# Getting pure gold (shining)



## Noxx

Hello,
I would like to know what I must add/change to a standard AR process to get pure gold after melting it. Most of the gold buttons I get are not completly shining and seem to have a very thin layer of impurties. How can I correct that ?
Thanks


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## darkelf2x1

try an acid wash after the melt down to clean up the gold, but your probably better off waiting for the pros on the board


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## Noxx

No acid wash won't help...


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## Fever

Try increasing your surface area prior to AR cleansing. You can do this by "shotting" your gold, which essentially means to pour your molten gold into water so that it forms BB's similar to rifle shot. This would allow the acids to interact with more of the gold surface. Just an educated guess really, hopefully some of the heavyweights will chime in on this....

Fever


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## Harold_V

It has everything to do with how you're refining. 

There are NO shortcuts. If you want pure gold, you MUST follow accepted practice. Remember, those that went before us have gone through this time and again----and have perfected a process that will yield good quality------so if you're interested in achieving that level, follow instructions that are at your disposal. Don't experiment-----leave that for others with time on their hands that are content to re-invent the wheel. This is particularly important for you, considering you're trying to establish a refining service. 

Depending on what you're starting with, you may have a hard time achieving a good level of purity the first time through. That's to be expected. Part of the problem is mechanical drag-down, where you're working with very heavily contaminated solutions, part of which follow the gold. They're not always easy to wash out, even when boiling with HCL. 

My advice to you is this:

Process your gold the first time, using conventional means. Allow as little in the way of contaminations (metals) as is humanly possible, to be included with the gold. Use only clean vessels. Wash them well between operations-----and use BonAmi cleanser if necessary to remove stubborn stains. Do not use other cleansers, for they scratch the glass. Filter before precipitating, and insure that the filter does not allow particulate matter to pass. If it does, re-filter, or go to a better filter grade. A Whatman #2 does an outstanding job for first refined metals, although they are not cheap. I used them exclusively for filtering first run gold chloride. I felt they were worth the extra money. At all times, keep your beaker covered with a watch glass of appropriate size, to prevent contamination from other sources. 

Precipitate your gold using conventional methods, collect it and wash it well. It's best to use a precipitant that does not add contamination. I preferred SO2, but there are others that work equally as well, I'm sure. 

First wash should be in boiling HCL and tap water. Boil for a prolonged period of time. Take up the solution with tap water, decant after the gold has settled, then rinse with tap water, which should again be brought to a boil. After it has boiled for a period of time, add more tap water to cool the lot, then decant as before. Rinse again, and do it until the wash water comes off clear. Next, wash the gold with ammonium hydroxide and tap water. Heat it until it boils. You'll notice that the solution gets discolored. How much is determined by how dirty your gold was when you started. The ammonia evaporates fairly quickly, so you can't boil very long. Add tap water to cool, decant, and follow up with a tap water rinse, again, boiling the water. Add tap water to cool, then decant. You now repeat the HCL and tap water wash. You'll be amazed that suddenly more contaminants will come off. Boil well, add water to cool, decant, repeat the water rinse, decant, then, and this is important-------start the refining process all over again by dissolving the well washed gold powder in aqua regia. I'll talk about that in a minute, but these are indicators you should have observed along the way, aside from the fact that you could see contaminants being washed from your gold powder. 

The gold powder, which started out quite dark, is now much lighter in color. 

It may have been rather loose and flocculent, but now is eager to agglomerate, so it forms lumps and settles quickly. 

While these instructions sound like a lot of wasted time, when you process what you think is pure gold, you'll see evidence in the remaining solutions that it was not. The evidence of which I speak will be in your solution when you've extracted the gold for a second time. It's a lot of work which is why I re-refined my gold in large lots, often as much as 200 ounces at each refining, so the time spent yielded a large return. 

When you precipitate for a second time, one of the things that you can do to help eliminate unwanted elements is to use a different precipitant than the first time. I never bothered with that, but it's good advice if you're fighting with a given contaminant and can't get rid of it by other means. That was never a problem for me. 

Wash the gold powder the second refining by the same methods and sequences as the first refining. Make sure all your equipment is scrupulously clean. Force dry the gold when it's washed by heating the beaker at a very low heat for a long period of time. Avoid allowing the beaker to achieve boiling temperature---you get minor steam explosions that blow gold out of the container. As the gold dries, it's a good idea to swish it around the beaker occasionally, which prevents the gold from bonding to the beaker. The residual matter in water tends to form around the gold and bond it to the beaker. While it's a contaminant of sorts, it does NOT alloy with your gold, so it is not a source of lowering the fineness unless you have strange elements in your water. For me, it was not a problem. 

Once dry, you can then melt your gold. A clean, never used for anything but pure gold, dish can be used. It should be covered with a coating of borax, but nothing else. DO NOT USE ANY SODA ASH. If there are any oxides present, they'll be reduced and absorbed by the molten gold instead of locked in the flux. 

Your torch should be cleaned of loose crud before melting your gold. Run fine abrasive cloth over it until it's very clean, then wipe it down with a damp cloth to remove any traces of dust. Think clean every inch of the operation-----otherwise you undo all the hard work you've done getting your gold pure. 

Your other option is to operate a small gold cell, but you must have several ounces of pure gold for the electrolyte.. That is likely not a viable choice for you at this point in time.

Harold


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## Harold_V

Fever said:


> Try increasing your surface area prior to AR cleansing. You can do this by "shotting" your gold, which essentially means to pour your molten gold into water so that it forms BB's similar to rifle shot. This would allow the acids to interact with more of the gold surface. Just an educated guess really, hopefully some of the heavyweights will chime in on this....
> 
> Fever



Gold is NOT cleansed via AR----that dissolves the gold, and it makes no difference if you start with melted gold or not, although melted gold dissolves at a much slower rate, so it's a good idea to not melt unless you are striving to eliminate something that comes out upon melting. However, melting, alone, will not yield pure gold. You can remove traces of oxides by a sulfuric pickle, but if you re-melt the gold, you quickly discover they are not gone. The contamination isn't a surface thing, it's throughout the gold. Thus, you can't wash melted gold and improve it's quality to any degree----the contaminants must be left behind when the gold is precipitated from solution, then the gold powder washed well to eliminate dragdown. 

Harold


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## goldsilverpro

Harold,

Did you pre-mix the aqua regia. If so, did you use urea or did you boil it down to syrup to get rid of the nitrates?

OR,

Did you use the two acids separately to keep from using excess nitric, thus eliminating the need for urea or boiling down?

I think you told me the latter but, I can't exactly remember. That's the method that I prefer.


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## Harold_V

No one in their right mind premixes aqua regia. It gasses considerably once mixed, so it is nearly impossible to store without problems. That's not to say you can't, but why would you? It takes but seconds to combine the acids, and there are no hazards involved regards heat reactions. What would anyone gain by pre-mixing? 

The only exception to that might be for making testing solutions, which are normally created in very small volumes, so the problems associated with storing them are correspondingly smaller as well. 

When I dissolved gold, it was rarely done blindly. I had a reasonable idea of the amount of gold present, and had concluded that an ounce of nitric (tech grade) with no less than 4 ounces of HCL would dissolve a troy ounce. An excess of HCL presented no serious problems, but it had to be evaporated due to my particular method of refining, so I tried to hit the proper volumes as closely as possible. I always started slightly low, and allowed the acid to work until totally exhausted. I'd take the beaker to the state of boiling. Once there were no further signs of brown fumes, I'd add a little more HCL to the mix to see if there was any further action. If not, the evaporation process was started, assuming there was no gold left undissolved. If all the gold hadn't been dissolved, I'd add a calculated amount of nitric to the mix and watch for a reaction. If there was none, I'd add a little HCL. You get pretty good at it, so you don't use too much. 

Key to success is working in a fume hood, where you can heat the acids and get instant results. If a guy is working for pleasure and doesn't care if it takes a day or two, whole different story, but I had to get things done. I often had as many as ten batches of gold in process at one time, with more waiting in the wings. Refining time had to be short, without short-cutting quality. 

I used no shortcuts for the evaporation process aside from using a button of once-refined gold to consume any extra added nitric that wasn't needed. I didn't use urea, and I wouldn't use urea now if I was refining. I see no need. The button was weighed before it was introduced to the lot, and weighed when it was removed in order to trach the amount of added gold. Unused nitric was consumed without adding volume to the container by this method. 

I used the evaporation process for more than one reason. I wanted my solutions as concentrated as possible, especially when re-refining. Precipitation, being an exothermic reaction, there wasn't enough cooling capacity for the process to be successful without icing -----so I used concentrated solutions (well evaporated, so they didn't destroy the filter paper) and added ice to the beakers for precipitation. That step was very important to success. You may recall that I used SO2 to precipitate. I was very pleased with it-----but you do need a fume hood. 

Although sue considered my operation a knee jerk affair, I processed thousands of ounces of gold over the years. I'd put my quality up against that of any major refiner------unless they were parting in a cell. I don't think I'd claim four nines, but one of my customers had my gold assayed and reported that that particular lot was found to be 9997. I was pretty proud of that. I have no doubt that some of my results would have been 9999, but I also think it wouldn't be routine. 

Harold


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## goldsilverpro

Harold,

I guess I had misunderstood you earlier. I thought you were alternating acids to prevent excess nitric, as I was. But, both ways work.

I probably haven't evaporated an AR solution in 28 years. I have never used urea in aqua regia solutions. This is because I never have any excess nitric, ever. The first few drops of my precipitating agent dropped gold. This is the proof of no excess nitric. If you have excess nitric, the precipitant reacts with the nitric before it drops gold. I started out following Hoke to the letter and, in 1979, I worked for a guy that was the greatest refiner I have ever known. He showed me the trick. I've covered this several times but, no one seemed to pay attention. I've never heard of anyone else doing this. The last time I owned a refinery, I shipped gold weekly as 99.99% and got top dollar. This was spectroed several times and always was up to par. I never had a lot rejected.

(1) As you did, I calculated, approximately, how much of each I needed and measured them out. For uninquarted Karat gold, this was about 125-150 mL of HCl and 25 mL of HNO3. My mentor didn't measure anything out. He just poured the acids back and forth from gallon jugs and never overadded

(2) Put the gold in a beaker or pyrex coffee pot and put this in a 5 quart white Corning Ware dish, in case of breaks and dribbles. Cover the gold with the HCl and heat it until steaming. I usually also add about 5% - 10% water. To make things easier, try to make sure you've added a little more HCl than necessary. This extra won't cause any problems.

(3) Add a small amount of nitric and let it work until the reaction slows down. Give it a slow stir and then another addition. Repeat this until there is no reaction with a fresh addition. Note: At the first addition, the reaction is vigorous and then, it slows down quickly - this addition is consumed quickly. The next addition will be less active at first and will take longer to complete - and, so on. When you first learn this, you might overshoot the nitric. After doing it a few times, you'll hit it right on the button. You have to get used to how it feels. At first, if you add too much nitric, you can always use urea but, it'll never be as pure.

(4) Add a bit of HCl, let it heat up, and watch for a reaction. If there is no reaction, you are finished. If you started with an excess, this will be the case. If there is a reaction, add some more HCl and let it heat up.

(5) If the HCl reacted, add a bit more HNO3 and watch. If there's a reaction, wait until it stops and add a bit more. Repeat until no reaction and try the HCl again.

(6) The idea is to go back and forth until you've hit the exact amount of nitric and, at least enough HCl. If you added a slight excess of HCl to start with, however, you won't have to go back and forth much. I rarely used all of the nitric that I had initially measured out.

Towards the end, go very easy on the nitric additions and give them a long time to completely be consumed. Towards the end, the pieces will be well caked with silver chloride and the acid penetrates slowly. Towards the end, keep it real hot - just below boiling. Towards the end, stir often. Also, during the process, stir before each addition. Always keep the beaker or pyrex coffee pot covered with a watch glass or a kitchen saucer when you're not stirring or adding. Never boil the solution. If you do, you can't tell the difference between fizzing and boiling.

When it's finished, transfer to a clean bucket. Add 3 times it's volume of tap water. This dilution will precipitate about 99% of the silver as silver chloride. To about 4 gallons of dilute aqua regia, add about 60 mL of battery acid and stir. This precipitates the lead. Allow to settle.

I'll go over the precipitation later.

NOTES:
(1) For Karat Gold, this direct dissolving could take as much as 8 hours. You will probably dissolve only about 98% of the gold, on the average. The remaing undissolved gold should be inquarted.

(2) To speed things up and dissolve 100% of the gold, you can first inquart the karat gold (reduce to 25% gold) with copper or silver, dissolve in nitric, pour off the nitric and rinse a few times, and treat the remaining gold powder in a much smaller amount of aqua regia. This process will take about 4 hours, after the gold has been shotted.

(3) If you only have 10Kt gold, or less, you can leach all of the silver, copper, zinc, etc., with nitric, without inquarting. Keep it quite hot.

(4) This method will do about 5 tr.oz. of karat gold in a coffee pot and about 10 oz. in a 4 liter beaker. I keep the amount of gold low to keep the solution levels low. Once the solution level is more than about 3" deep, the reaction is slower. I usually had 8 or 10 setups working at the same time.

It was late and I was tired when I wrote this. I'll look it over tomorrow to check for errors.


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## Harold_V

goldsilverpro said:


> Harold,
> 
> I guess I had misunderstood you earlier. I thought you were alternating acids to prevent excess nitric, as I was.



I think we're not communicating well, or I may have stated what I did in a poor fashion. While I may have worked slightly differently from what you described, the objective was the same. I did alternate acids, and I never premixed my AR---it was mixed on demand. Our processes were very much alike. 

The problem with your method, and mine as well, is that you *can* introduce too much nitric. I was always careful to not do so, evidenced by the amount of added gold in each batch (from the button used in evaporation), and always evaporated to full expulsion. I routinely added additional HCL a couple times as the solution reduced to heavy concentration, which insured that the nitric was consumed. A small amount of the added gold being dissolved assured me that all the gold in the lot had been digested, that there was none left behind. That was to insure that the customer wasn't cheated. 

Your method would have been in serious conflict with my procedure-----I had to keep the level of concentration very high, as I outlined. The one advantage to yours is that you worked with much more dilute solutions, so mechanical dragdown was likely reduced. Had I not re-refined my gold, that would have been a problem. I've mentioned it before, but I'll do it again. When I re-refined my gold, I ran it in large lots, starting with 75 ounces. That was split in four beakers for precipitation. Each beaker was a 4000 ml----that started with a liter of gold chloride. To that I'd add ice to bring the level up to a full beaker. I then immediately precipitated the gold. When the gold was down, the solution was hot. As I said, precipitation is an exothermic reaction, which gives up all the heat energy used in dissolving the gold. 

One comment on 10K. While it does process without inquartation, you can inquart and process far faster. I processed school rings by the pound------and wouldn't dream of not inquarting. The difference in process time is hours------hours I couldn't waste. 

Harold


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## goldsilverpro

Harold, I'm very glad to know that you use the acids separately. Most people don't. How did you learn to do this? I haven't read Hoke for awhile but, I don't remember her doing it.

I'm glad that this all important thread finally occurred. This stuff is hard to explain but, is very straightforward in practice. Hopefully, the readers can understand what we're saying. If not, they should ask specific questions until they understand the mechanisms used in both our processes. Also, those others who are producing good gold should participate and detail their processes. Every good refiner uses the same basics but, all vary in the details. The more variations we know, the better we can settle on our own excellent process.

We both understood early that, besides getting all of the gold, high purity had to be the main goal. This is what separates the men from the boys, in this business. It's just as easy to produce good gold as it is to produce bad gold. The basic steps are the same. It's all in the details - the tricks.

Harold, you're right. It's always possible to add too much nitric. At the start, I did it more than a few times. More nitric makes things go faster and there's a tendency to overadd. However, when I discovered that I had to pay the piper, down the line, I developed more patience. Urea produced less pure gold and I avoided boiling down like the plague. With a little experience, I learned to avoid overadding and it got to the point that it didn't happen. 

There's one thing I don't understand, Harold. How did you get rid of the silver? You obviously did, but I can't see how. When I first started, I ran experiments to find out how much silver would dissolve in aqua regia. I found that silver was quite soluble in concentrated aqua regia but most of it dropped out at a dilution of 3 to 1. After that, the curve flattened out and further dilution didn't drop much more. I found that, if I didn't dilute at the start, the silver would come out later, when the aqua regia was diluted by the rinses. This would combine with the dropped gold and contaminate it.

Sometimes, when my one furnace was tied up, I ran the karat gold scrap as is. Usually, though, I inquarted. Inquarting gives several advantages. It is faster in the long run, although there are additional steps. The aqua regia dissolving is very fast, the solution gives much less volume to work with, and the solution is mainly gold, since most of the other metals are eliminated by the nitric. This higher purity aqua regia makes it easier to end up with pure bars. And, maybe the most important, you don't have to deal with that nasty silver chloride that sets up like concrete on the stuff you're trying to dissolve.

I don't remember the nitric leaching of 10KT gold taking that long. I would guess 3 or 4 hours. I usually did it on large batches of class rings. I had a couple of class ring manufacturers that gave me their scrap.

In recent years, I rarely had to redissolve and go through the aqua regia process twice. The times I remember involved the first drop being contaminated with platinum group metals. I eventually learned to get rid of the Pt. gp. early on.


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## lazersteve

goldsilverpro said:


> I eventually learned to get rid of the Pt. gp. early on.



What do you mean by 'early on' ? Please explain how you would remove the PGM's.


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## Harold_V

goldsilverpro said:


> Harold, I'm very glad to know that you use the acids separately. Most people don't. How did you learn to do this? I haven't read Hoke for awhile but, I don't remember her doing it.



Two things lead me to work that way. One was the fact that there is little agreement on what constitutes the proper ratio of HCL and nitric when making AR. I've read a ratio of 3/1 and up to 5/1. Armed with the idea that too much HCL does no harm, I started adding more HCL almost at the outset of my learning curve. Still used too much nitric, because I wasn't familiar with the behavior of the chemicals, but as my skill increased, the excesses diminished. 

Understand that I relied on a small overage. It was my way of insuring the customer wasn't cheated. If, when I evaporated, the button of gold I added to the dish didn't give up some weight, there was a distinct possibility that I had left behind some of the customer's gold. That's not hard to do if you're running filings, or if your shot, from inquarting, was run poorly in the nitric operation. 



> We both understood early that, besides getting all of the gold, high purity had to be the main goal. This is what separates the men from the boys, in this business. It's just as easy to produce good gold as it is to produce bad gold. The basic steps are the same. It's all in the details - the tricks.



I feel we each develop our own methods, but if you deviate too far from accepted practice, your results can, and probably will, be suspect. I have a lot of respect for those that went before us. They went through all of these things time and again----and, luckily for us, passed on their findings. As far as I'm concerned, only if a person can't acquire a particular chemical is there reason to not follow accepted practices. The sole exception would be if one's hobby is to experiment. If the goal is to extract and purify gold, getting cute and creative is likely to lead to a considerable amount of frustration, and yield less than acceptable quality. 

The other point to consider, and it's diametrically opposed to my thinking and logic, is that some of these guys have no interest in the gold-----to them it represents nothing but money. If they can extract (concentrate) the gold, then market it to others at a reasonable price, their objective has been met. Wouldn't work for me, for I have a killer instinct that drove me to perfection----but that doesn't make me, or them, right or wrong. 



> Harold, you're right. It's always possible to add too much nitric. At the start, I did it more than a few times. More nitric makes things go faster and there's a tendency to overadd. However, when I discovered that I had to pay the piper, down the line, I developed more patience.



That was the best teacher I could get----even though Hoke spoke of the subject, you have to step in that oil before you understand how dirty your shoes will get! :lol: 



> There's one thing I don't understand, Harold. How did you get rid of the silver? You obviously did, but I can't see how.



Depends. When running filings, which yield very dirty gold the first time through, I simply filtered it from the gold chloride. When inquarting, there was very little left behind, and it was also filtered from the chloride solution prior to precipitation. 



> When I first started, I ran experiments to find out how much silver would dissolve in aqua regia. I found that silver was quite soluble in concentrated aqua regia but most of it dropped out at a dilution of 3 to 1.



Please accept this comment in the spirit in which it's offered!  

That's nonsense! It is common knowledge that silver can not exist in an acid solution in the presence of chlorine. I've yet to read anything that would support what you said, with one exception. Rose discusses the fact that the odd atom of one element will display characteristics of another, in this case he was discussing silver and gold, at least as I recall. Remember, I've been away from this stuff for well over ten years, and as I've stated time and again, all my books are in storage. At any rate, my choride was always taken up with water, although very little. Anything that was willing to precipite did, and was filtered off. I never found traces of silver in the second refining----*NEVER*.



> After that, the curve flattened out and further dilution didn't drop much more. I found that, if I didn't dilute at the start, the silver would come out later, when the aqua regia was diluted by the rinses. This would combine with the dropped gold and contaminate it.



What you're describing sounds like lead, not gold. Unless you had assays run to verify what you experienced, I'd question your observations. I can state with honesty that I never experienced anything like that---but I always insured that I had discharged traces of lead. 



> Sometimes, when my one furnace was tied up, I ran the karat gold scrap as is. Usually, though, I inquarted. Inquarting gives several advantages. It is faster in the long run, although there are additional steps. The aqua regia dissolving is very fast, the solution gives much less volume to work with, and the solution is mainly gold, since most of the other metals are eliminated by the nitric. This higher purity aqua regia makes it easier to end up with pure bars. And, maybe the most important, you don't have to deal with that nasty silver chloride that sets up like concrete on the stuff you're trying to dissolve.



Before you prime newbies with the idea that they can run karat gold that way, with success, please try to remember that silver is not soluble in AR. It converts to a hard, impenetrable crust that stops AR dead in its tracks. I've done my share of experimenting in that regard, and know all too well that you can literally boil 14K gold in AR for days and not have it dissolve. Readers should understand right off that if there is a content of sliver that exceeds 10%, you're likely to have great difficulty dissolving gold unless the cross section is so thin that the metal has been fully penetrated before the chloride layer has been fully formed. That's why it was a successful method for running filings, although even in that case they were first treated to a prolonged boil in nitric, to remove as much silver and base metal as was possible. Karat gold was my bread and butter-------I ran it daily in multiple batches. 



> I don't remember the nitric leaching of 10KT gold taking that long. I would guess 3 or 4 hours. I usually did it on large batches of class rings. I had a couple of class ring manufacturers that gave me their scrap.



Yes----3 or 4 hours. Inquarting made that a half hour, and eliminated the follow up operation, whereby you had to melt the bits that refused to dissolve, inquart, and start over. It delayed the batch too long. It was just plain faster, easier and better to inquart at the outset. 



> In recent years, I rarely had to redissolve and go through the aqua regia process twice. The times I remember involved the first drop being contaminated with platinum group metals. I eventually learned to get rid of the Pt. gp. early on.



You're not going to try to convince me you achieved 9999 that way, are you? Nothing I've ever read indicates that's a reasonable expectation, and my personal experience, and I'm damned thorough and careful, lead me to believe that it's nearly impossible. I do think you can achieve 9995 with reliability----as long as you're not processing filings that have not been melted and inquarted. 

I agree with you in that if one is to refine, setting the goal for anything less than 9999 makes no sense, but achieving it isn't easy. Only parting properly with a cell will yield consistent results, and then you're at the mercy of your support equipment. Something as simple as a dirty torch tip can lower the fineness (they shed copper oxide). I wasn't willing to settle for less than the industry standard of 9995, and worked hard to exceed it. I was very happy with my results, and think I would be less than truthful if I was to claim consistent 9999. 

Harold

Edit: changed words so they made sense


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## lazersteve

Harold said:


> whereby you had to melt the bits that refused to dissolve, inquart, and start over.



Harold, 

I experienced this same situation even after inquarting? :? Is this because I didn't get the gold to fully alloy with the silver? 

What is the accepted process for alloying gold and silver for inquarting
( i.e.: 3 parts silver, 1 part gold, melt gold, add in silver, mix (?), etc.).

Thank you for your valuable input.

Steve


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## lazersteve

Harold said:


> I do think you can achieve 9995 with reliability----as long as you're not processing filings that have not been melted and inquarted.



Harold, 

Am I correct to conclude that this to means inquarting is a precusor to higher purities?

I have adopted the purer is better mentality lately. The thing I noticed right off of the bat was the additional work involved in attaining the higher purity product. I think it's worth the extra work if you really want the purest gold possible. My goals are sort of a cross between yours and some of my own. I'm not processing gold for the money, but for the future value. I've sold a few ounces of my gold early on, but now I'm stockpiling it as a retirement plan. Knowing it will be worth more when it is the pureest possible, I'm driven to attain the highest purity I can. 

On the flip side, time is of no concern for me as it was for you. You had many customers waiting in the wings, where I have only my curiosity and desire to learn as my driving force. Since I have more time to ponder the philosiphy of gold refining, I tend to be creative and try out some uncharted territories along the way. Granted I waste some time doing so, but I too must step in the oil to realize how dirty it is! :wink: 

Keep up the great post Harold, I sincerely feel you are the heart and soul of this forum.  

Steve


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## goldsilverpro

> That's nonsense! It is common knowledge that silver can not exist in an acid solution in the presence of chlorine.


Harold,
One of the first things I learned was that silver chloride is soluble is strong aqua regia. Not a lot but, certainly enough to severely affect the final purity of the gold. It reacts similarly to lead but, to a lesser extent. Before dilution, the filtered solution is perfectly clear. Upon dilution, the dissolved silver chloride precipitates. Therefore, the standard way of precipitating it is to dilute the aqua regia. Some say 2 volumes. Some say 4. My experiments said 3. I was quite surprised that you didn't agree with it. Nearly every refining book I've ever read states this fact. And, it is a fact. I don't have a copy of Hoke any more but, I seem to remember that she mentioned it. You might check your copy.

My experiments were simple. I cooked some AgCl in standard 3/1 aqua regia, filtered it, most probably through glass fiber filter media, and then analyzed the silver dissolved in the aqua regia by atomic absorption. Then a I diluted it a bit, filtered it, and again ran it on the AA. I repeated this several times and then plotted it on a graph. Three dilutions removed most of it.

I only have 4 refining books left. Two didn't mention it. The first edition of Ammen (pp117) said to dilute it 3 or 4 times but, didn't say why. 

I did find more than a mention of it in the last book. This was in a an IPMI (International Precious Metals Institute) book of the papers that were given at the 1980 IPMI Symposium on Recovery, Reclamation, and Refining of Precious Metals, held in San Diego. I was an IPMI member at the time and attended. The IPMI is probably the most prestigious PM organization in the world. In the papers, is a long article entitled "Silver Chloride". Here's a quote from that paper, page 3. The author documents these statements but, I won't supply the references unless you want them.

"It (silver chloride) is somewhat soluble in concentrated HCl and heavy metal chlorides. Solubility in these increases with temperature and concentration. Solubility in chlorides appears to be by the formation of complex chloroargentate ions.... Solubility in HCl and heavy metal chlorides is of interest because of how it relates to aqua regia systems. In aqua regia dissolution the liquid consists of a very concentrated mixture of heavy metal chlorides, usually at elevated temperatures. These are ideal conditions for the dissolution of AgCl. Even small amounts of silver chloride, if left in solution, can have a marked effect on the purity of the gold produced. This is especially true for the third and forth decimal places of fineness. Fortunately most of the AgCl can be removed with water. One to two volumes are *usually recommended* for this dilution during the clarification stage."

So, what I said is true. 

I've thought about your process to try and determine why you had no silver problems. (1) If you always inquarted, your aqua regia would have much less heavy metal chlorides so, less AgCl would be retained. The experiments I ran, however, showed some retention with no heavy metal chlorides but only aqua regia alone. (2) After boiling down, I assume you added water (diluted) and filtered. This is probably where you got rid of it.



> Before you prime newbies with the idea that they can run karat gold that way, with success, please try to remember that silver is not soluble in AR. It converts to a hard, impenetrable crust that stops AR dead in its tracks. I've done my share of experimenting in that regard, and know all too well that you can literally boil 14K gold in AR for days and not have it dissolve.



Although neither of us likes the direct aqua regia process, without inquaration, it is the standard aqua regia process that most refiners use. You and I are in the minority. As I understand, one reason you used it was because you wanted to get every milligram of gold dissolved so you could be honest in accounting with your customers. Most refiners could give a damn about 100% honest accounting. They know that, sooner or later, it'll all come out in the wash. Of course, by that point, it would belong to the refiner. In my case, when using direct aqua regia, it was on already purchased material. I rarely worked on a recovery basis. I preferred inquarting because, as one of your reasons, I hated fighting with the silver chloride. If you reread my post, you will see that I never promoted direct aqua regia. I just showed how it was done.



> You're not going to try to convince my your achieved 9999 that way, are you? Nothing I've ever read indicates that's a reasonable expectation, and my personal experience, and I'm damned thorough and careful, lead me to believe that it's nearly impossible.





> What do you mean by 'early on' ? Please explain how you would remove the PGM's.



Early on in life, Steve.

In 1969, I was head chemist for a large refinery in L.A. Our Wohlwill Cell (gold purification cell) solution was often too contaminated with base metals and required frequent solution changes, in order to maintain high purity gold. I started experimenting with ways to extend the life of the solution. We had a well stocked lab and had quite an assortment of chelating agents. Most were variations of EDTA. Chelate comes from the Greek word Chelos, which means "claw". It grips metals in several places, like a claw, and holds them in solution. I figured that, if I added EDTA to the solution, it would chelate the base metals and prevent them from plating out with the gold.

When I added the specific type of EDTA to asample of cell solution, all of the gold dropped out. Surprise, surprise. For about a hour, I was very disappointed. I really thought it would work. Then, it dawned on me that I might have a new precipitating agent for gold. I started doing lots of experiments and maximized the process. We melted several batches of gold dropped from heavily contaminated aqua regia, under pristine conditions, and sent off samples to be analyzed for all impurities. To my amazement, none were under 99.99% pure. Some approached 99.999%, believe it or not. Some of these aqua regia solutions were intentionally contaminated with all of the platinum group. Still, the gold was above 99.99% pure, with only one drop. I'm not saying that the company always shipped 99.99% gold, because they could introduce impurities during the melt. I am saying that the powder was most always 99.99%.

None of the company experts could figure out why it worked. Later, I concluded that formaldehyde, a common gold precipitant, was released when the EDTA product neutralized the aqua regia. You could smell it. The base metals were tightly held into the solution and didn't come out with the gold. I never could figure out what happened with the silver and platinum group but, somehow, they were held into the solution. The company pretty much shut down the Wohlwill operation and went with my invention for everything. We called it EZ-Drop. I was a hero based on a failed experiment. The company was running about 10,000 ozs/month and ran the process for several years, until they were bought out by a big conglomerate.

When I left, I continued using it until about 1980, although I always kept some around for gold containing platinum group. From the late '80's though the mid '90's, when I owned my last refinery, I had no need for EZ-drop. I specialized in recovering 80/20, gold/nickel braze from military and commercial jet engine parts. Another reason I stopped using this product was that chelating agent wastes, with their tightly bound heavy metals, are very difficult to waste treat. The EPA hates them. Also, the EDTA product was expensive. In 1969, it cost about $650 per drum, of which, under optimum conditions , you could drop about 3000 ozs of gold.

*Note to Harold* I am correcting something in the third from the last paragraph. When we sent out the EZ-Drop samples, we didn't melt them. We sent them out in powder form. The melted samples were for another project. It's been 38 years and I remembered wrong.


----------



## Harold_V

goldsilverpro said:


> That's nonsense! It is common knowledge that silver can not exist in an acid solution in the presence of chlorine.
> 
> 
> 
> Harold,
> One of the first things I learned was that silver chloride is soluble is strong aqua regia. Not a lot but, certainly enough to severely affect the final purity of the gold. It reacts similarly to lead but, to a lesser extent. Before dilution, the filtered solution is perfectly clear. Upon dilution, the dissolved silver chloride precipitates. Therefore, the standard way of precipitating it is to dilute the aqua regia. Some say 2 volumes. Some say 4. My experiments said 3. I was quite surprised that you didn't agree with it. Nearly every refining book I've ever read states this fact. And, it is a fact. I don't have a copy of Hoke any more but, I seem to remember that she mentioned it. You might check your copy.
Click to expand...


Well, your comments are certainly in keeping with what Rose had to say about random silver atoms behaving as if they're gold. Just checked my Merck index, which clearly states that it is "superficially attacked by HCL", which likely explains the entire subject, particularly when I read your comments below. . 

I'm going to quote your entire statement, below, thinking that what you have to say is very important, but most of all, revealing. Good stuff, Maynard!



> My experiments were simple. I cooked some AgCl in standard 3/1 aqua regia, filtered it, most probably through glass fiber filter media, and then analyzed the silver dissolved in the aqua regia by atomic absorption. Then a I diluted it a bit, filtered it, and again ran it on the AA. I repeated this several times and then plotted it on a graph. Three dilutions removed most of it.
> 
> I only have 4 refining books left. Two didn't mention it. The first edition of Ammen (pp117) said to dilute it 3 or 4 times but, didn't say why.
> 
> I did find more than a mention of it in the last book. This was in a an IPMI (International Precious Metals Institute) book of the papers that were given at the 1980 IPMI Symposium on Recovery, Reclamation, and Refining of Precious Metals, held in San Diego. I was an IPMI member at the time and attended. The IPMI is probably the most prestigious PM organization in the world. In the papers, is a long article entitled "Silver Chloride". Here's a quote from that paper, page 3. The author documents these statements but, I won't supply the references unless you want them.
> 
> "It (silver chloride) is somewhat soluble in concentrated HCl and heavy metal chlorides. Solubility in these increases with temperature and concentration. Solubility in chlorides appears to be by the formation of complex chloroargentate ions.... Solubility in HCl and heavy metal chlorides is of interest because of how it relates to aqua regia systems. In aqua regia dissolution the liquid consists of a very concentrated mixture of heavy metal chlorides, usually at elevated temperatures. These are ideal conditions for the dissolution of AgCl. Even small amounts of silver chloride, if left in solution, can have a marked effect on the purity of the gold produced. This is especially true for the third and forth decimal places of fineness. Fortunately most of the AgCl can be removed with water. One to two volumes are *usually recommended* for this dilution during the clarification stage."
> 
> So, what I said is true.
> 
> I've thought about your process to try and determine why you had no silver problems. (1) If you always inquarted, your aqua regia would have much less heavy metal chlorides so, less AgCl would be retained. The experiments I ran, however, showed some retention with no heavy metal chlorides but only aqua regia alone. (2) After boiling down, I assume you added water (diluted) and filtered. This is probably where you got rid of it.



I had to think about that for some time. The method I pursued could have easily included traces of silver as chloride, based on your quoted comments, for which I thank you. 

Incidentally, I have the loose-leaf from the same symposium you mentioned (IPMI), but mine is dated March 10-13, 1981, San Diego. 

I obviously eliminated silver chloride, although unbeknownst to me, when I did my wash with ammonium hydroxide. I knew it was removing copper that didn't come out with the first HCL wash, but had not considered that I might also be removing silver. If that is not the case, then my gold certainly must have contained traces. While I diluted my solutions, they were never diluted by three times (I already covered that in my previous post)-----but I can clearly see that there is a benefit in doing so. I never had my gold assayed, and had a customer not done so, I'd have never had a clue. I just worked on my quality until it would melt without traces of oxides, and had a great surface. It think we're in lock step in that regard----those qualities come only from very pure gold. 



> Although neither of us likes the direct aqua regia process, without inquaration, it is the standard aqua regia process that most refiners use. You and I are in the minority. As I understand, one reason you used it was because you wanted to get every milligram of gold dissolved so you could be honest in accounting with your customers.



I've never had the privilege of touring a major refinery----so I'm not at all up to speed in what they do,and how they do it. I stand to learn a considerable amount in that regard. 

I'm held captive by my trust in Hoke's book. I had messed with my gold in the hopes that I could produce clean gold without jumping through all the hoops. My first button was frosty, leaned somewhat green, and was obviously not pure. I tried to dissolve in in AR by boiling for hours, which turned into days. The silver content was way too high to permit dissolution, and the button ended up with a very ugly coating of silver chloride. It may be soluble in AR, but not enough to permit refining without reducing it to respectable levels. As I said, I boiled my button for hours on end in AR, and dissolved no gold in the end, once the impervious layer of chloride had formed. 

I finally read the book and resorted to inquartation. Miracle of miracles, I ended up with relatively pure gold once I followed the instructions and quit being cute and creative. That's why I always recommend the newbie follow good and accepted practice. It's not because I do it that way, and there's no other way-----it's because it's very simple to do, and best of all, it works, and works every time. I fully realize there are other ways, perhaps some of them even better, but it's pretty hard to beat the basic process Hoke presents-------and they can be done without expensive equipment. I assume major refiners are heavy into contained vessels of sorts, where they can conduct these dissolutions at elevated temperatures and can deal with the resulting fumes, likely recycling them to the source of origin. Care to comment on that? 



> In 1969, I was head chemist for a large refinery in L.A. Our Wohlwill Cell (gold purification cell) solution was often too contaminated with base metals and required frequent solution changes, in order to maintain high purity gold. I started experimenting with ways to extend the life of the solution. We had a well stocked lab and had quite an assortment of chelating agents. Most were variations of EDTA. Chelate comes from the Greek word Chelos, which means "claw". It grips metals in several places, like a claw, and holds them in solution. I figured that, if I added EDTA to the solution, it would chelate the base metals and prevent them from plating out with the gold.



Excellent explanation of a process snipped ------

That certainly explains your position,and I thank you for that. Clearly, what I had to say is true----first refined gold is unlikely to exceed 999-----and is often far worse. Your process was and is very impressive. 

On that subject, the IPMI literature I have in my possession addresses pretty much the same thing, but in refining the platinum group. Instead of precipitating the platinum from dirty solutions, they precipitate the base metals, then go after the values. I don't recall any of the details----it's been well over 12 years since I last read the papers, but, once again, your concept is well supported by the endeavors of others. 

I hope readers have learned something from this long drawn out post. I know I have. 

Harold


----------



## Harold_V

lazersteve said:


> Harold,
> 
> I experienced this same situation even after inquarting? :? Is this because I didn't get the gold to fully alloy with the silver?
> 
> What is the accepted process for alloying gold and silver for inquarting
> ( i.e.: 3 parts silver, 1 part gold, melt gold, add in silver, mix (?), etc.).



Not being fully alloyed would certainly be one of the things to consider. The other would be if you had used enough nitric acid, or not. If you're working your metals cold (no hotplate), it's a lot easier to achieve the results you did. Heating makes a huge difference in that the turbulence tends to keep the insoluble in suspension and keeps the solution in action, better exposing the metal to the acid. Hot acids work much faster than cold acids. 

Gold and silver will eagerly combine, but you do have to give them a reason. My normal procedure was much the same as a manufacturing jeweler would use, which is to simply stir the heat with a carbon rod. You can buy them from a jewelry supply store, or you can even use a carbon rod that is used for air arcing metals. Welding supply stores sell them, although you might have to buy a box. Any good sized welding shop would probably have them and sell you a couple. They're not very expensive. A buck should buy you a rod. They last a long time, slowly burning away where they contact the molten metal. So you'll know, they break fairly easily, so get the largest one you can find, for strength. I used ½" diameter rods. They're a bit "clunky" at first, but the end burns away to form a taper, so you end up with a small end that works for small lots. 

The stirring takes only a second or two, but be advised that the carbon transfers heat quickly. I held my carbon rod with a pair of wheel weight pliers----which doubled as the gripping device to pour the molten mass into my container of water (I used clay melting dishes for small lots). The angle of the pliers was perfect for that purpose, but a bit of a compromise for stirring. No matter, you do it only briefly, anyway.

When you pour your metal into water, there's no better way than to simply pour out of the lip of your melting dish in a fine stream. Move about over the water so you don't concentrate the metal in one spot. When I poured large heats, it wasn't uncommon to end up with a large mass otherwise. Pouring this way doesn't yield shot-----it yields what I like to call corn flakes. They are thin and irregular, and dissolve quickly. 

It's important to keep the gold content around the 25% bracket. You won't always be successful, for there are surprises. If you get involved with a lot of dental gold, for example, you have to add a serious amount of silver to offset the higher gold content. By sharp contrast, if you run a batch of 10K, particularly old 10K, that is actually borderline 9K, it takes very little. My policy was to add about 105% in silver of the weight of the mixed scrap gold I'd process. It kept me in the ballpark. Considering 14K is 58.3%, you ended up quite close to 25% gold content. 

The problem with inquarting too low (under 25% gold) is that you risk the gold breaking into fine powder. That's not a problem, all you have to do is wait for the stuff to settle before decanting. For me, that wasn't a good thing because of the need to turn the gold quickly. 

If you don't use enough silver, the nitric process will not be successful in that the gold is so dense that it eventually isolates the undissolved metal from the acid. In that case, all you can do is give the stuff a prolonged boiling in nitric, and hope you penetrate to the center. If you start over, you have to add a huge amount of silver because you're dealing with near pure gold on the exterior. I think you see where I'm going with this. 

The other negative of not having enough silver is that you don't get a clean extraction with the first operation, so the metal you dissolve isn't as clean as it otherwise may have been. As you might imagine, the cleaner your solution, the cleaner the gold will be that precipitates. It's also important that the precipitant you use is very selective Some reagents have a propensity to precipitate other elements to some degree, and there's always the problem of drag down. Washing the gold well after precipitation is key to improving the quality, but a second refining really does the trick. By then, your contaminants are very few, and if you don't add anything to your solutions to yield a color (I didn't), you can see what is left behind by the second refining. It was always a proud moment when my solution was clear. A sure sign that my first refining had been carried out well. 

It might not hurt to mention that not all gold needs to be inquarted. White gold, for example, can be directly dissolved in AR with success (no silver), but you miss out on the first operation, where you remove base metals. I don't recommend the procedure, but it does work. 

The gold you're recovering from your cell needs no inquarting, as I'm sure you know. Just don't melt it. If I was to refine it, I'd incinerate it, papers and all, getting it hot enough to convert carbon to CO2. Avoid heating to the point of forming prills. I'd then give it a wash in boiling HCL, rinse, and go straight to AR. The gold from that operation would, in all likelihood, not need a second refining. The HCL wash should remove anything that's questionable. Be sure to keep Hoke's recommendation in mind to add a few drops of sulfuric when evaporating, if you go that route. You may not need it, but it does no harm. If you go the urea route, I'm afraid I'm not much help-----I never used it, nor would I if I was refining now. 

Tonight I may have learned something that should have been obvious to me. GSP had claimed that some silver goes into solution in AR. Rose had discussed that to some degree in his book, but there was no explanation as to the cause. GSP provided that information. I suggest that if you refine in small quantities, that you dilute your solutions. If you run concentrated solutions like I did, be certain to do an ammonium hydroxide wash to remove traces of silver chloride that get through the operation. 

I'd like to comment on your quest for pure gold. I'm very pleased to hear you talk that way. There is no doubt in my mind, to do anything less, particularly in your situation, where your intention is for retirement, you couldn't make a more sound decision (it worked for me!). You open the door to selling your gold to any consumer, and at full value. Otherwise you'd be locked in to selling to a refiner, or to a recycling source. You can always fall back on that in an emergency. No reason you shouldn't put that money in your pocket, and the reward from turning out ultra pure stuff is worth the effort in personal satisfaction. My proudest moments were always when I was finished with re-refining large batches. 

When the day comes that you can melt your gold and not have oxidation, you'll know you're getting close. It's not all that hard, Steve. Take it slow and easy, as you have, and it will turn out fine. Pay strict attention to your washing cycles, and keep your vessels clean. Keep your vessels covered with the appropriate watch glass, too. I washed my glassware with BonAmi to remove any traces of staining. You have to have a different mindset when you strive for better than 9995!

Harold


----------



## Harold_V

lazersteve said:


> Harold said:
> 
> 
> 
> I do think you can achieve 9995 with reliability----as long as you're not processing filings that have not been melted and inquarted.
> 
> 
> 
> 
> Harold,
> 
> Am I correct to conclude that this to means inquarting is a precusor to higher purities?
Click to expand...


In my opinion, yes. It stands to reason that anything you do to remove unwanted substances from your gold before it goes into solution will decrease the contaminants that come down with the gold. They need not precipitate to contaminate------they hitch a ride mechanically---and don't always wash out well. Eliminate them and there is nothing to ride with the gold. 

You also have to keep in mind that some things simply don't contaminate gold. Water, for example, that has no heavy metals contained within, will not add negative things to your process. That it contains other elements is obvious, but they just ride through the process. They don't report in the final product. 



> I have adopted the purer is better mentality lately. The thing I noticed right off of the bat was the additional work involved in attaining the higher purity product. I think it's worth the extra work if you really want the purest gold possible.



I've already commented on your quest-----and I wish you luck. Trust me, Steve, the pure gold is its own reward! It's worth the effort, especially for guys with a hint of perfectionism. :wink: 

Harold


----------



## lazersteve

Harold said:


> The other would be if you had used enough nitric acid, or not. If you're working your metals cold (no hotplate), it's a lot easier to achieve the results you did.



I'm sure I used enough nitric (70% Lab Grade). I even poured off the first batch and added more to be sure. I didn't get much more action. I think heating is the issue. Since I don't have a fume hood yet I do everything cold and just wait it out. As I've stated many times, I'm in no hurry. 

Oddly enough the inquarting I filmed for the Separating Silver from Gold tutorial worked fine with no heating. Maybe I didn't get quite enough silver in the alloy on this batch? The last possiblity is the amount of powder gold that has formed, it almost seems as though it's preventing the nitric from contacting the alloy. I've been stirring the solution on a regular basis and it still seems to be SLOWLY eating away the last tiny bits of the alloy. Hoke mentions in one of the early chapters of her book to go thru the gold powder after inquarting looking for bits that have not dissolved. She recommends adding them to future inquartation batches.

Thanks Again Harold,

Steve


----------



## goldsilverpro

Steve,

The gold powder forms a crust on the pieces you're dissolving just as silver chloride forms a crust in the aqua regia. This greatly slows down penetration of the nitric. Heat would help enormously. With strong heat, you could most probably get 100% dissolution quickly. I have used nitric, many times, on 10KT (40% gold) and have been left with nothing but gold powder.

Another possibility. I assume you torch melted when you inquarted. If so, you may have gotten incomplete mixing of the alloy. This could have created some pieces that were richer in gold when you poured the shot. It's easier to mix the melt in a crucible furnace. You simply stir with a carbon rod. You can buy these rods or scrounge them. They are used in arc lights. You could probably use these to stir the torch melt. If you preheat them to red, before stirring, no gold will stick to them. You can also use the rods to remove slag, although it won't stick to a red hot rod. To remove slag and not the gold, just heat the rod slightly. This is touchy. If it's too cold, it will pick up gold and slag. If it's too hot, it won't pick up anything. If it does pick up gold, just melt it back into the dish. I've never tried it on a torch melt but it should work. Probably, just holding the rod above the melt for a few seconds would heat it enough. Just wipe the rod quickly around the edge of the melt and remove it.

In the tutorial, you may have had less than 25% gold. I wouldn't recommend going much lower than 25%, though. When you do so, the gold can come out as a very fine slime. It seems to never settle and it is very hard to filter.

You need heat, unfortunately.


----------



## Harold_V

lazersteve said:


> I'm sure I used enough nitric (70% Lab Grade). I even poured off the first batch and added more to be sure. I didn't get much more action. I think heating is the issue. Since I don't have a fume hood yet I do everything cold and just wait it out. As I've stated many times, I'm in no hurry.



There were a few batches I ran that were difficult to process. In my case it was a matter of not having added enough silver, so the end result is much as you describe. Even with a hard boil for a prolonged period of time, there were occasions when all action ceased, yet the core of the material being processed didn't have the base metals removed. 

What I discovered in that instance is that you're more or less between a rock and a hard place. The only thing that works with certainty is to melt any un-dissolved pieces along with an ample amount of silver, to lower the gold content. Seems like if you run the first results in AR to exclude the gold, by the time it has been removed, the silver exposed will have formed a hard crust and makes running the balance of the material in nitric next to impossible. Re-melting eliminates all the headaches. However, in your case, where you're not in a hurry, could be that you'd have respectable results simply by allowing the remains to sit in some nitric. Do remember that nitric will be more active with some water included. I'm at a loss to explain the hydronium ion, but it, somehow, comes in to play and does wonders for dissolving silver. Reagent grade nitric is slow to attack silver, but does so with a vengeance with the slightest addition of water. I experienced that routinely when I made electrolyte for my parting cell. I think GSP could verify this information as well. 

All of this tends to be troublesome and clumsy at first, Steve, but it gets to be routine and happens seamlessly as you progress. You arrive at the point where it's no big deal-----you just do it -------and it works. And when it yields problems, you'll understand why, and instinctively know what to do to solve them. 

Keep us posted!

Harold


----------



## goldsilverpro

> Reagent grade nitric is slow to attack silver, but does so with a vengeance with the slightest addition of water.



Very true, Harold. I think you hit the nail on the head. I've always read that a 50/50 blend of concentrated nitric and water works the best. In practice, I've found this is true and always end up cutting my nitric 50/50. Of course, I always use a lot of heat. When cold it will probably be different. Try about 10% - 20% distilled water. You might need a little more power, than normal, to cut through the gold barrier.

Another problem is that, in most cases, strong acids hold less metal, per volume, than weaker acids. Remember your working with solubility constants in chemistry. One exception is the solubility of silver in sulfuric, which works opposite - don't ask me why. When using concentrated nitric, the solution quickly becomes saturated with silver. Sometimes, you'll see silver nitrate crystals form on the chunks of metal. This can grind the reaction to a halt. Dilution increases the solubility of the silver. 

I always dissolve big silver contact points in nitric. I cover the points with cold distilled water and start feeding in the nitric, a little at a time, to keep it from foaming over. A vigorous reaction starts almost immediately, even though the solution, to start, only contains about 10% nitric and the solution is cold. Soon, I have all the nitric in that I've calculated it needs, plus enough water to make 50%, by volume. The bucket is so hot you can hardly touch it. In the morning, everything is dissolved. The only thing left is the crud.


----------



## lazersteve

You guys have a great point, but the reason I specified the concentration of the acid was to make clear that I wasn't using 'homemade nitric acid'. I diluted it as per my tutorial approximately 50/50 (1 part 70% HNO3 to 1 part distilled H2O) which would be close to 35% HNO3.

Steve


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## goldsilverpro

Back to square 1. Can't you heat it even a little? Maybe, run your heat gun over it a little? Maybe a little more strong nitric will help.


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## lazersteve

Sure I can , give me a few minutes and I'll let you know how it goes.

Steve


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## lazersteve

I heated the beaker until it was warm to the touch. No signs of a reaction, no bubbles, no vapors, nada. I added 10 mL more of 70% Nitric, nothing. The total solution size is about 100 mL.

The remaining pieces look silvery red with a moss of brown powder clinging to them. They are about the size of BB's. I see four of five of them amongst a 1/4" deep mossy brown mass. When swirled you can barely make out the BB's.

What next?


Steve


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## Noxx

Maybe you could try to break the gold «crust» covering the pieces with a glass rod...


----------



## lazersteve

It's not so much a crust as a loose moss. When I swirl the beaker it floats off of the BB's freely revealing the silvery red metal underneath.


----------



## Harold_V

lazersteve said:


> It's not so much a crust as a loose moss. When I swirl the beaker it floats off of the BB's freely revealing the silvery red metal underneath.



Red flag!
Check the item with a magnet. It sounds like you may have a piece of iron that's precipitating copper----but that's a long shot. If it is copper, adding new acid should dissolve it-----but you say it doesn't dissolve. 

When you inquart properly, the gold left behind, unless it breaks down to fine powder, which is often black, will be a dark reddish brown color, and will usually be the perfect image of what it was prior to dissolution of base metals, although it might be slightly smaller. There would be no reason for globules to grow (if they're not copper)------unless they are gold globules, being precipitated by some unknown element. None of your gold should have gone into solution with this process, so my money is still riding on the thing being magnetic. This is a strange one, Steve.

Harold


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## lazersteve

Harold,

Thank you for the reply, the material is *not* magnetic, I just checked it with a very powerful magnet and it didn't budge.

Here's a closeup of the stuff:







It's hard to see so I circled some of them in the photo.


Steve


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## Harold_V

Long shot, Steve. Could you have possibly included some aluminum in the lot? Something has to be responsible for the growth of which you speak, and it should be soluble in nitric. After all, what it grows from came from nitric solution. Aluminum would be a likely candidate at it is not soluble in nitric, but would easily precipitate copper (and silver).

I'm baffled! 

If it was up to me, I'd boil it hard in nitric, then go to AR----and let the chips fall where they may. Once in a while you come across something that seemingly has no solution. I'm not suggesting this is one of them, but without being able to do to it what I would do to it, and make observations that may mean something to me, based on my past experiences, I'm afraid I'm out of guesses. Keep posting your results, and maybe we can get this thing resolved. 

Were it not for growing nodules, I'd suggest all you need to do is re-melt with more silver, but this thing bothers me-----the growth does, anyway. 

Can you tell me what you started with? If so, can you describe each piece to the best of your ability? There may be something in what you used that's key to this thing. Some newer jewelry, for example, has no precious metal content. Class rings are amongst them as I recall. Sure could be wrong, though. I've been away too long. 

Harold


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## lazersteve

The source material came form the stripping cell.






I'm sure you've seen the pictures of it along the way here and there on the forum. I melted it without flux and it appeared to be mostly gold with a hazy or milkly (hard to describe) whitish red surface coloration weighing 11.5 grams. I was shocked at how impure the cell gold came out this time exactly the opposite of what I expected :?: 

From here I parted the gold with the silver I showed you earlier :






I melted the silver and gold together in a brand new clean melting dish and cornflaked:






I put the cornflaked material in a beaker with diluted nitric acid. The results are as you saw in my previous post.

Steve


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## Noxx

Thanks for the great replies guys. I'll probably build a tutorial on this when I will get good results. Thanks to Harold for the quick How-to guide.


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## Harold_V

Steve,

We'll get this figured out now!  

How I wish I'd have had a chance to talk to you about the material from the cell before you inquarted. 

One of the purposes of inquartation is to expose gold so it can be dissolved. In your particular case, the gold was already very finely divided------which explains its color (colloidal), as you know. In this instance, there is nothing to gain from inquartation, although I figure you probably did so for a tutorial. 

This material would have been a perfect candidate for a direct AR process, no inquartation required, simply because you already had it finely divided. You can even reduce unwanted elements when in this state. The nice thing is, with proper pre-treatment, you very well could come up with 9995 (or better) gold without a second refining. The finely divided state of the material is ideal!

One of the great ways to eliminate an unwanted acid, so it won't affect the next operation, is to incinerate. That also oxidizes elements, so they might go into solution when they, otherwise may not have. Copper oxide, for example, is soluble in sulfuric, but clean copper is not. I've mentioned this because there are times when you must go from a nitric dissolve to an HCL wash before extracting gold. Jewelers floor sweeps are a good example. Incineration eliminates the nitric, so the HCL doesn't touch the gold, but cleans up the material so you don't have problems with filtering your gold chloride solution. 

Anyway, I'd have incinerated what you had, then boiled it in HCL, which would have removed substances that make filtration of gold chloride difficult. That's a critically important step if the source of your gold is related to tin, which, in electronic scrap, is very likely. 

After the HCL wash, I'd rinse the material with water, allowing everything to settle well before decanting. Hot water accelerates the settling time. If the solution was quite dirty, I might give it more than one rinse. Once I was satisfied, I'd go directly to AR. 

Now that I understand the source of your material, can you tell me how much silver you used as compared to the weight of the gold? In this instance, you'd have to use roughly three times the weight of the gold, which you would assume to be pure for the sake of the calculation. 

If you used less, and you didn't stir, you have probably landed on the source of your problem. The un-dissolved bits are likely high karat alloy---better than 10K. They won't break down in nitric once you've dissolved the surface away. The gold, which normally honeycombs, is too dense to permit penetration of the nitric. That condition is to be expected if you didn't use enough silver, or some of your gold didn't get well mixed with the silver you added. I still have no explanation for the growth you've experienced. 

Harold


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## lazersteve

Harold the ratio of silver to gold was just shy of 3 parts sliver to 1 part gold. Lack of proper stirring must have been the problem.


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## PhillipJ

Trying to understand all that's going on in this topic is a little above myself. Although I did learn a lot. Just trying to figure out what evaporate means.

Anyhow, I took Harold's advice on washing the gold & got a lot of garbage out. On 2nd refinement I tried to control the nitric as best I could, but it still needed a little urea.

Before I precipitated, I diluted 3x water then added a good slug of sulfhuric acid like GSP says, and filtered it. I warmed the solution on a coffee plate and precipitated with sodium met. I boiled a little water and mixed the sodium met then dumped it in. It kinda boiled in a flash when I added it. The plastic spoon I used to stir it with came out coated with yellow shiny gold.

The gold that dropped was also a shiny gold color. As if it was gold dust. Not all of it dropped, so I added a little more sodium met. and the rest dropped a light brown like it normally does.

Anyone know what happened that it dropped all shiny? It's a real light tan / gold color and acts slippery like silica sand. Or is it really that clean and supposed to be that way?

In the pictures, the little white dots are reflections of light on the shiny gold mud.


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## Harold_V

Congratulations, Phillip!

That light color you referenced is exactly what the pure stuff looks like. When I used to discuss the second refining, I'd often comment on how 
"blonde" the gold came down. 

I'm not sure I know what I'm going to say is true, but my thoughts are that when there is little in the way of contamination present, the crystals of gold will grow larger, thus they begin to develop faces that reflect light directionally. Very finely divided gold doesn't do that, and eventually diffuses light in all directions, so you see it as black, or dark purple. In addition, because the gold has little in the way of contamination, it's far more eager to agglomerate. You'll notice that when you abrade the stuff, it will shine as if it's been melted. Dirty gold powder won't do that, or, if it does, it takes a lot more energy to make it do so. 

There is no doubt in my mind, the color of the gold, as it precipitates, is a good indicator of the purity, but in no way should be construed as an assay. 

I'm pleased to hear you found evidence of contamination upon washing---it's an important step that can't be stressed too much. Relying on flux to purify gold is a serious mistake. Sort of like wearing perfume instead of taking a shower!  

I'd like to comment on the use of plastic when precipitating gold. I've already stated that I don't recommend it. It has a strong affinity for precipitated gold, so unless you recycle the containers after use, you'll lose values. Your gold plated spoon is exactly what I'd have expected. 

If you use a glass vessel that isn't scratched, you can use a plastic policeman to rid the glass of clinging gold. Scratched vessels become a real problem. Gold will firmly attach to the scratches, making removal almost impossible. My work habits revolved around using specific beakers for precipitation. As old beakers were retired, I'd promote the beakers, and start using the new ones strictly for precipitation. If you're using other vessels, the same concept would apply------so keep that in mind when you select your labware. 

Evaporate can be taken literally. When you use too much nitric, one of the options to rid the solution is to evaporate it until it's expelled. You heat the solution (best done in an evaporating dish, which presents a very large surface for evaporation, but it can be carried out adequately in a beaker) at a low heat, allowing the contents to go into the atmosphere. If you do it at the proper speed, it happens with no losses of values. If you go too fast (too hot), you can often see a slight yellow tint to the gasses------a sure sign you're losing gold. 

As you evaporate, your solution changes color. It borders on the impossible to tell you from what to what, because the color is heavily influenced by the metals contained within. Assuming you have only gold, it starts life somewhat honey colored, and darkens to a deep red as the solution evaporates. If you add HCL (which actually helps expel the nitric, but you have to carry the evaporation to the red stage before it does), the solution reverses color and gets lighter, and you can often see a brown cloud coming off (that's the nitric being expelled). 

Hope the explanation helps. The best advice I can offer you is to get a copy of Hoke's book------it's totally outlined. Get the book, even if you can successfully process gold. There's one hell of a lot of useful information in it for the novice. I can't over state the value of that book. 

Harold


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## goldsilverpro

PhillipJ, 

Great looking gold. You've really come along fast. If you rinse and melt it well, you're going to have a very high purity ingot.

Harold,

I agree with you in most every aspect. You know my feelings in the plastic vs glass controversy, so I won't get into that. I would like to discuss the subject of cleaning up impure gold in the melt.

It's much more difficult to clean off purity gold in a melting dish than in a crucible furnace. However, it can be done in both. I'm talking about gold that still has base metals in it. I'm not talking about gold contaminated with Pt group metals. With Pt group contamination, you have to start over and redissolve it in aqua regia. 

I try, as you do, to do everything possible to get the gold very pure before melting it. Sometimes, though, it is slightly off purity and needs a little flux work. At this point, I will play with it until it is pure. It takes, at the most, 10 extra minutes. Probably, 98% of the time, I am successful. If I understand your past posts, you see the need for fluxing as a bad thing and will put it right back through aqua regia. I don't understand your reasoning and maybe I have misunderstood you. I look at flux cleaning as only another gun in my arsenal. The end product is all that counts. It doesn't matter how I get there. 

The blond gold is great when you get it, but it's not necessary for pure gold. At least, not that I've ever noticed. Most times, the darker gold is just as pure. The darker gold is more finely divided and, therefore, is harder to rinse. I never really paid much attention to color, since I had developed good rinsing techniques and I knew I could clean most anything off purity in the melt. We both knew what high purity gold looked like. The gold we both produced met these stringent visual requirements. You ran your gold through twice. I ran mine once and cleaned up problems in the melt. Both ways worked. Same end product. Same deep pipe, gorgeous color, and super well-defined crystal.

I worked for a guy that was the best refiner I've ever known. Along with silver cells, his main expertise was karat golds and he could do them faster than either of us could imagine. He didn't inquart but he cast a bar and ran it through a huge set of power rolls. He rolled it paper thin, then coiled it up and put it into aqua regia. If it was brittle, the rolls crumbled it into a jillion pieces. In both cases, it had much more surface area than any shot you've ever seen*. After aqua regia, he melted in a dedicated pure gold furnace and was a master at flux cleaning. I would guess that he could clean gold as low as 99.5%, or less. For gold he couldn't clean - a rarity - or gold with Pt group, he ran it back through aqua regia and used a different precipitating agent.

* I noticed that, in the link for the Italian refining machine that aflac gave, they use a metal atomizing gun to shot the gold. This would be the absolute best way to optimize the dissolving speed of the aqua regia.


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## PhillipJ

Harold,

Thank You for your advice here. I like to read what you have to say at this site because of your hands on experience.

Had it not been for this site and folks like yourself I would have continued to refine poor quality gold without knowing any better. Now I am going to reprocess what little I do have.

Nobody that I know, or ever heard of around my area does refining or even has a clue that there are precious metals in electronic scrap. That leaves me to do much by the seat of my pants. The supplier of the sodium nitrate only gives limited directions.

It's great that guys like you and the other experienced refiners here are willing to share their tricks so us newcomers don't have to guess and wonder.


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## Harold_V

goldsilverpro said:


> It's much more difficult to clean off purity gold in a melting dish than in a crucible furnace. However, it can be done in both. I'm talking about gold that still has base metals in it.



The thinking is flawed where fluxing to purify is involved. Fluxes do not remove clean metals, only the oxides. Unless you introduce something to fully oxidize the metals, they won't be removed, regardless of the system. The only improvement you can expect is the removal of already oxidized metals, and then only if the entire mass is exposed to the flux. To further complicate the matter, If you get stupid and add reducing agents (soda ash, for example), you not only don't remove the oxides, you reduce them and add them back to the gold as clean metals. The gold will come out shiny if kept under a flux cover, but it is not pure. 

Clearly, melting under a flux cover has a limited effect on the fineness of gold, We're that not the case, all a refiner would have to do is melt his gold with flux and have it come pure. Both of us know that doesn't happen. Fact is, that's the reason I started double refining. Fluxing alone would not improve the quality to my level of satisfaction. I can't speak for others. 



> I try, as you do, to do everything possible to get the gold very pure before melting it. Sometimes, though, it is slightly off purity and needs a little flux work.



That may have happened to you, but it didn't happen to me. Now you understand why I asked you about your reports of consistent 9999 gold. As I've already stated, I double refined my gold for years to avoid the problem----secure in the knowledge that it rarely comes down in good quality the first precipitation----. Further, the quality suffers far more with gold from dirty solutions. Directly dissolving karat gold with AR by thinning it is a great example of asking for problems. The base metals, along with silver, are included in the solution. Why would you expect to precipitate 9999 quality, when drag-down alone would be significant. Remember, I never said it wouldn't work----fact is, I refined bench filings that way, and got terrible quality gold as a result. It was that gold that became my added metal for evaporating solutions. By melting it, the quality was slightly improved, but the second dissolution proved the key to success. Buttons that came from that gold were always off color (oxides).

It's been well documented that it's not easy to exceed 9995 with the AR process, although not impossible. As a result, I double refined my gold-----if for no other reason, I am an honest person and don't enjoy lying to myself, let alone a customer. I made no guarantee that my gold exceeded industry standard of 9995, although it surely did----but I *did* guarantee it met the standard. It was a safe way to conduct business-------no one calls you a liar when they get more than they bargained for, but you'll never be forgiven if you advertise 9999 and deliver 9997. 

Notice that my ingots were marked simply "Fine Gold"? It was. 

My method of melting was very telling of impurities. For one, the gold had every opportunity to get fully oxidized, not being melted under a flux covering, and an oxidizing flame used, not a reducing flame. That was on purpose. Should there be any base metals, the gold not only would come out discolored, but the melting dish would show signs of oxides. I'm very proud to announce that my melting dish was used until it was too thin to be of service, and was colored light purple-----time and again. So, my friend, while my first run gold may have been questionable, my second run gold was not-----ever. The only purpose flux served in my case was to "grease' the melting dish. There was NEVER a flux cover, just enough flux to keep the dish wet. There is no oxide to absorb when there are no base metals present. My second run gold never required a pickle. 

On the subject of the color of gold when it precipitates, I made observations, and not once, but over years. I was always more concerned with quality than I was profit------so, to me, this was an important issue. The things I mention, below, are absolutes as far as I'm concerned, and were well supported by the end results I achieved. Please bear in mind that I used sulfur dioxide to precipitate, so nothing was added to my solutions to influence colors. 

1- Gold that precipitates from dirty solutions will come down dark. It's a function of the contamination level. It is NEVER pure. It isn't just a matter of being finely divided, although being finely divided is symptom of being dirty. 

2- Gold that precipitates from clean solutions will come down blonde---without fail. The sole exception is if the solution is quite dilute, at which time the gold forms smaller crystals, but they never lean towards black, they are slightly darker golden colored, and not as bright as larger crystals. The color, when washed, does not change, for they are dark because they are finely divided, and not reflecting light directionally. 

3- Gold that precipitates dark, from dirty solutions, will always lighten in color with a good and proper washing. That involves more than a rinse---it requires boiling with HCL, rinsing well, and the use of ammonium hydroxide. There is no question, the quality of the gold is improved by this process. 

4- Gold that precipitates light in color (blonde) generally changes little, if any, when washed. The color is light, and it stays that way. A sure sign the gold is pure. The wash solution does not change color, for it is absorbing nothing. 

To me, the observations I've made indicate that the color of gold as it precipitates is a very good indicator of the quality. It would take a lot of evidence to sway my opinion, and I've not seen enough thus far to have that happen. 

Harold


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## Harold_V

PhillipJ said:


> Harold,
> 
> Thank You for your advice here.



You're very welcome. Phillip. I take great pleasure in assisting those that have a similar agenda to one I had. Not everyone cares about the overall quality, but to me that was of uppermost importance. 



> Nobody that I know, or ever heard of around my area does refining or even has a clue that there are precious metals in electronic scrap. That leaves me to do much by the seat of my pants. The supplier of the sodium nitrate only gives limited directions.



It's not uncommon to find most folks lacking even the most basic of understanding of gold or silver refining. Gold, since '32, was so tightly regulated by our government that it was illegal to refine unless you had a federal license. As a result, little has been published in that regard, and what little that has been published, aside from Hoke's book, has been at a level that would be unlikely to be useful to the novice. I encountered that at every turn when I was attempting to learn. Had it not been for my good fortune to place a phone call to an elderly benchman that had experimented with refining, and owned a copy of Hoke's book, it's very possible that I would have stumbled along with no success. 



> It's great that guys like you and the other experienced refiners here are willing to share their tricks so us newcomers don't have to guess and wonder.



Aside from passing along the things that I confirmed by observations, and the pursuit of perfection, I take no credit for any of the things I post. Hoke's book was key to my success. If followed, you will be successful, although there may very well be other methods that yield comparable success. That's not the point-----Hoke hands the information to you --------there is almost no learning curve. You might keep that in mind if you move beyond gold and work with the platinum group. 

Harold


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## goldsilverpro

Harold,

We could argue about these things til the cows come home. I just hope our bantering is instructive to the readers. I think we both have to search our memories to come up with this stuff. I know I do. No matter how we did it, we both came out with very similar final products. I admire you for perfecting a system to put out pure gold. You should realize, however, that probably no one else in the world uses your exact system yet, there are many other aqua regia refiners that put out gold as pure as yours, with one drop, myself included. From day one and many 10's of thousands of ounces later, besides the economic aspects, super pure gold has always been a pride thing with me. You're the only person I've ever met that routinely uses double aqua regia. I see your logic behind this. I just took a different approach.

About half of the gold I sold went into the manufacture of gold plating salts. Since I started out in the gold plating salts industry, this is where my contacts were. This industry has some of the most stringent gold purity requirements of any other industry. These salts were mainly sold to electronics mfgrs. and were all made with 9999 gold. Anything less would show up in faulty plating and the salts mfgr. would be out of business. My gold was suitable to enter this system.

Since pure gold ingots have a specific visual appearance, I chose to do nothing that would eliminate these visual effects. I wanted any educated buyer to have no doubts that my gold was pure. I didn't fire polish or buff the surface, for example. I didn't stamp my bars. I NEVER tried to sell gold that had oxide discoloration and never used acid to remove it. In my system, this discoloration was rare. When it happened, I remelted and cleaned it up. When I couldn't clean it up, I put it back into aqua regia, the last resort, as far as I was concerned.

In your post, you used words like, "the thinking is flawed" and "stupid", when referring to my methods. Although these words get my blood pressure up a bit, I try to calm down and look at this thing logically. I think that sometimes you feel that anyone with different experiences than you is flat out wrong. When we were refining, we operated in different worlds of industry. Your business was mainly with jewelers. Mine was in the more broad high tech world in L.A., mainly in the electronics manufacturing sector. We both satisfied our customers with pure gold. Most likely, your gold would be satisfactory in my sector and mine in yours. As Steve's signature says, "The proof is in the pudding."

I don't know where you got the idea that I cover the gold with flux. I never allowed that to happen. That would have really been stupid. I only used very small pinches of flux, mainly alternating between borax and niter. I usually used one pinch of soda ash, at the start, to adjust the flow of the flux. If it did reduce oxides, it made no difference, since all were eventually removed with niter. The molten gold forms a convex meniscus and the flux slides to the edge of the button. When I had too much flux, I usually let the gold barely solidify and then poured off the still molten flux. I'm talking about when using a melting dish. When using a crucible, it's diameter was much larger than a melting dish and the buildup of flux around the edge of the meniscus isn't as much of a problem. When you add niter, you can see the oxides rise to the top from the interior. The melt is always kept moving with the torch. When base metals are still present, there is a whitish film on the surface. This is a surface effect caused by the oxidizing flame and/or the oxygen in the air. When the base metals are gone, the gold has a brilliant metallic mirror surface with no evidence of white. Further additions of niter don't affect this surface. All of this is much easier to perform in a crucible furnace.

In order of decreasing particle size, gold goes - shiny metallic - blond - tan - light brown - medium brown - dark brown - almost black - black - black slime - purple, all with intermediate shades in between. With all of these, on a microscopic level. the individual particles are bright and shiny and probably crystalline. Only the eye sees them in bulk, in these colors. I would wager that I could, with some experimentation, start with 9999 gold and produce each of these colors, by varying the parameters. When refining, I have seen every one of these. In my experience, the finer gold is, the more difficult it is to filter, leach, and rinse out the contaminates. When really fine, these things become impossible. Therefore, the finer the gold, the more likely the gold will be impure. I always shot for lumpy, fluffy, light or medium brown gold. More like a sponge than a powder. This stuff rinses and leaches beautifully, maybe even easier than the heavier blond powder. Sometimes, the last, maybe 1%, of the gold dropped darker than the rest. I don't know why this happened, but it seemed to cause no problems, since the bulk was of good color..

When filtering, our leaching/rinsing system was a bit different. I went hot water rinses - approx. 50% nitric leach - hot water rinses - ammonia leach - hot distilled water rinses. We both used ammonia. I used it for silver chloride and, I think, you used it to detect any blue solution of nickel or copper. Only traces of these metals produce a strong blue color in the ammoniacal solution. I rarely got any blue because of the large amount of rinsing done, on my spongy gold, before the ammonia. You used HCl and I used nitric. I feel that nitric will remove everything that HCl removes, plus more. I never did understand why you used HCl.

By "dirty solutions", do you mean those that have base metals in them or those that have been improperly filtered?


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## aflacglobal

This might sound a little gay, but i love you guys. where have you been all my life ?

I can only hope to gain the knowledge you gentlemen have.

I can pretty much follow the topics and i understand the math.
but still that's not the same as experience.

Thanks gentlemen,

Ralph


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## Harold_V

goldsilverpro said:


> Harold,
> 
> We could argue about these things til the cows come home. I just hope our bantering is instructive to the readers.



Why do you think I challenge you on subjects with which I don't agree? It is my objective to not only expose things that I feel are wrong, but to describe, to the best of my ability, what's wrong with them, as I see them. I'm not sue, who tossed a wet blanket on subjects but refused to say why. Readers should have every opportunity to not pick up bad habits, which both of us have, no doubt. Our discussions serve a good purpose, even if they annoy you. 



> I think we both have to search our memories to come up with this stuff. I know I do. No matter how we did it, we both came out with very similar final products. I admire you for perfecting a system to put out pure gold. You should realize, however, that probably no one else in the world uses your exact system yet, there are many other aqua regia refiners that put out gold as pure as yours, with one drop, myself included



If that was the case, why would any of them run parting cells, or for that matter, use the Miller process? 

Sorry, I don't agree. Everything I've read indicates that even 9995 on a consistent basis isn't a reasonable expectation for a first refining, and my experiences back that notion perfectly well. That isn't to say that you can't achieve it, but to expect it routinely borders on the unreasonable. I'd be particularly hard pressed to believe you can do so with karat gold that has been directly dissolved with AR by dividing it finely in lieu of inquartation, where base metal and silver content are reduced. The direct AR process isn't a great deal different from how I processed filings from a jeweler's bench, which consistently yielded poor quality gold, and that's after a prolonged boil in nitric until there was no further action. This was after incineration and before AR. Why would you, or anyone, expect gold that comes from a dirty solution (dissolved base metals of all kinds) to be as clean as gold that comes from a clean solution? You don't feel there's more dragdown? 



> In your post, you used words like, "the thinking is flawed" and "stupid", when referring to my methods



Sorry, you're wrong. I did not make reference to them because they are "your methods". I made my comments because they're true. Note that I did NOT tell you you were stupid, nor that your thinking was flawed. I have no clue where you were taught to use those processes, which could have very well been passed to you by someone that was well meaning, but poorly informed. 

If you use those procedures, that's your choice, but I outlined exactly what's wrong with them. Remember, doing something for an eternity that is not in your best interest will not turn it to something that *is* in your best interest. Hundreds of people doing something stupid doesn't make it smart. You get my drift. 

You may have learned to live with the consequences of these things, but I don't think I can stand by in clear conscience while you endorse methods that have a potential to create more problems than they solve. Both of them do exactly that. 



> Although these words get my blood pressure up a bit, I try to calm down and look at this thing logically. I think that sometimes you feel that anyone with different experiences than you is flat out wrong.



Wrong again. I've clearly stated that there are many ways to achieve the end result, but I've also stated in clear English that if readers follow the advice stated in Hoke's book, one thing is assured. They will achieve success. Not sometime, but every time. Fact is, even Hoke presented options. I chose to exercise those that appealed to me, or were most convenient. I do not think my way is the best, but it was the best for me-----having tried various means for many operations, in keeping with Hoke's recommendations. If they worked for me, they can work for others as well, saving them the task of reinventing the wheel. 



> I don't know where you got the idea that I cover the gold with flux



This sort of lead me that direction: 

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=337&highlight=needle+scaling

In the link you said:



> Needle guns are quite powerful. I used to use them to remove slag from ingots. They might break up IC's. The problem is to confine the material so it doesn't fly all over. Your chamber might just work. Not a bad idea."



I poured gold without any flux on my ingots. How did it, otherwise, get there on yours?



> Since pure gold ingots have a specific visual appearance, I chose to do nothing that would eliminate these visual effects. I wanted any educated buyer to have no doubts that my gold was pure. I didn't fire polish or buff the surface, for example. I didn't stamp my bars.



Yet you clearly stated "Needle guns are quite powerful. I used to use them to remove slag from ingots." 

Not only does slag leave tell-tale signs where it was on the ingot, but the removal by mechanical means, particularly by a scaler, defaces the ingot surface beyond recognition. You can't have it both ways. 



> I only used very small pinches of flux, mainly alternating between borax and niter. I usually used one pinch of soda ash, at the start, to adjust the flow of the flux. If it did reduce oxides, it made no difference, since all were eventually removed with niter. The molten gold forms a convex meniscus and the flux slides to the edge of the button



That reminds me of the guy that gets pulled over for running a stop sign. He insists to the cop that he slowed down---which is the same as stopping. Cops say to him------"Tell you what we'll do. I'll start thumping the hell out of you with my night stick. When you think you've had enough, you tell me if you want me to slow down, or stop".

Tell me, which would you prefer? You have a container of hot water and some salt. You don't want the salt in the water. Is it easier to keep it out, or to get it out once it's dissolved? That's the type of reasoning you're presenting to the readers. I don't agree, and I'm not going to agree in a week or a year. What a prudent individual does is keep it out, not toss it in and pretend it's not a problem. You, my friend, are passing a perfect opportunity to learn that soda ash is a reducer, and should not be included in flux for fine gold. You want to thin your flux? Use fluorspar. It does a better job, anyway. 

I don't recall EVER needing to thin my borax when melting pure gold. The only time it got thickened was when there was an abundance of base metals. I trust you read my comments about melting my second refining. Melting dishes had only one color beyond clear-----a purple tinge----from colloidal gold. Borax, when clean, is not particularly viscous at the melting point of gold, but quickly sets as the gold freezes. Pouring any off when the gold has set is a tall order. You might be successful in scraping it out. 

Hoke discusses raising the quality of questionable gold by the addition of niter (potassium nitrate). I tried it several times----never with success that was in keeping with my goal. Maybe you settled for less than I wanted. Dunno. I wasn't content to have gold that had oxides----and I never was successful in eliminating them by that means, not even after a quarter hour of heating with an oxidizing flame (a Hoke torch, fired by natural gas and oxygen). There was clear evidence they were lowered (dirty flux), I'll grant you that-------but-----again------if achieving high quality gold was as easy as melting with a proper flux, that's what we'd all be doing. It doesn't work---although it does remove some oxides. Maybe if I'd have spent a couple hours! 



> When I had too much flux, I usually let the gold barely solidify and then poured off the still molten flux



Been there, done that, got the T shirt, learned it didn't work. You don't think I tried every dodge in the book, too? I ended up double refining because it DID work, the other dodges didn't. My original method (first year or two of refining) of returning gold was to melt in a dish, with enough flux to reach the edge of the button, but not to cover it. The moment it froze, but was still red, I'd sprinkle a light covering of borax on the surface, then extract the button from the flux iwth tweezers. It was then pickled in sulfuric acid. The button was delivered to the owner, not shot. The flux, by now, was very sticky, and would not pour. 



> Therefore, the finer the gold, the more likely the gold will be impure.



This is a cause and effect situation. My observations were that gold precipitated from dirty solutions came down very fine---and dirty. I never did get gold to precipitate fine from clean solutions. It was so eager to agglomerate that the particles came down large, often very large. The contamination in dirty solutions prevents that from happening, at least from my observations. You're certainly entitled to see it the way you do------but I'm every bit as convinced that I am correct as you are. 



> I always shot for lumpy, fluffy, light or medium brown gold. More like a sponge than a powder. This stuff rinses and leaches beautifully, maybe even easier than the heavier blond powder. Sometimes, the last, maybe 1%, of the gold dropped darker than the rest. I don't know why this happened, but it seemed to cause no problems, since the bulk was of good color..



I'm pretty sure I can address the different colors. I've already stated that color is a function of concentration. Here's one for you to consider. 

On rare occasion, when I'd re-refine, I'd have a touch of nitric still left in solution. The gold came down fine, but when it came time to wash the gold (with HCL), I'd get the slightest of dissolution. Stop washing after allowing it to boil for a brief period (to consume the nitric with the precipitated gold) and then ice the solution. The precipitation from the now very dilute solution produced gold that was slightly darker than the balance of the precipitated gold. There was so little present that it did not agglomerate as well as the heavily concentrated solution on the original precipitation. 



> When filtering, our leaching/rinsing system was a bit different. I went hot water rinses - approx. 50% nitric leach - hot water rinses - ammonia leach - hot distilled water rinses. We both used ammonia. I used it for silver chloride and, I think, you used it to detect any blue solution of nickel or copper. Only traces of these metals produce a strong blue color in the ammoniacal solution.



No, I had no need to detect copper. It did expose it if it was present, however, for, as you allude, the slightest trace of copper displays a bold blue color. I'd find hints of blue, but not routinely. I used ammonium hydroxide for one reason. When you change pH, elements that are in solution are prone to precipitate, so by going from acid to basic and back to acid, I had the opportunity to convert any sort of contaminant the could prove troublesome. Washing well with ammonium hydroxide is just one more step you can take to improve the quality of gold without adding anything to it that can prove harmful.



> You used HCl and I used nitric. I feel that nitric will remove everything that HCl removes, plus more. I never did understand why you used HCl.



By now you should understand that I am a student of Hoke. I used HCL because it is the recommended wash. You do recall that we're talking about a chloride solution, yes? Unless you take steps to eliminate all traces of chlorides, you risk dissolving your precipitated gold when you wash with nitric. I think so, and Hoke thinks so. I wouldn't dream of using nitric for the final wash, and I'm not concerned that it worked for you, or not. Assuming you do the nitric wash, and have a negative reaction, you'd be walking a very dangerous line when you started introducing ammonia to a gold chloride solution, a risk I'd rather not take. One thing sure, you wash with HNO3 long enough and that's going to happen, just like the occasional batch that contained a trace when I washed. I don't want to be held responsible for providing even a hint of something that can jeopardize a reader unnecessarily. If you can present cites that prove my position to be in error, I'd welcome the input. You likely understand that I'm not all that keen on opinion. I already have some that we don't agree on. 

I'm not concerned if readers follow my recommendations, or not. What I am concerned with is that they use practices that don't create problems, and don't harm themselves or their loved ones. Follow the advice in Hoke's book-------the pitfalls have all been addressed. It will tell you how to wash your gold-------although I'm pretty sure it doesn't address the use of ammonium hydroxide. I had to learn that from a novice refiner. Wish I had my book at hand. 


Here's the deal. You bring an ounce of pure gold to my shop, and I'll provide one. We'll make a setup to refine the two ounces. I have enough nitric and HCL and sulfuric to do the processing. Together, we'll alloy it to 14 K yellow, then we'll process it by your means. If you can produce gold with a single precipitation that melts without oxides, the gold is yours. If it has oxides, any oxides, the gold is mine. I'm willing to put my money where my mouth is. I trust you have enough faith in your grandiose claims to do the same. 

Harold


----------



## aflacglobal

:shock: :shock: :shock: :shock: :shock: :shock: :shock: :shock:


----------



## goldsilverpro

My sentiments exactly, aflac.

I'm going to bow out of this, Harold, with a few closing statements. These long argumentative posts are wearing me out and we both are saying the same things over and over. It's a fact that we both produced excellent gold using different methods. This doesn't surprise me as much as it does you. I've probably known 50 professional refiners in my life and, with few exceptions, they all had similar goals and developed their own ways of producing good gold. I once worked for a guy who could care less about making pure gold. He shipped 99% and took a beating. This philosophy drove me nuts and I quit after a month.

Maybe, your dropping gold from concentrated solutions caused the first drop to be crappy. I seem to remember having trouble along those lines, At an early point in life, I started diluting the aqua regia 3 times before filtering and that seemed to take care of a lot of former problems.

I will concede that doing double aqua regia is a more guaranteed method of getting pure gold, especially for the novice. Maybe you're right in wanting these guys to do it. For me and every other professional refiner I've ever known, however, it's a big waste of time, energy, and money. Also, few or none of these guys inquarted. 

The Hoke book is the best book for the beginner that I know of. However, it was written 67 years ago and, since then, there have been a lot of innovations in aqua regia refining. 

Although an old method, the Miller chlorine/Wohlwill cell method is still the state of the art for refining gold. Once the initial outlay is covered, it's the cheapest, most reliable way of refining large quantities of gold. It's not used because the refiner can't get 9999 with aqua regia, no matter what you've read. It's like a refining machine, with set parameters and few variables. It avoids the very subjective method of using aqua regia. It avoids the workers screwing up the more sensitive aqua regia process. But, since it's very expensive to set up, only the big boys can afford it.

The definition of an ingot is metal in a bar form. The standard method for processing circuit boards is to burn - grind - screen - melt the metallics - ship the dust (pulps) and ingots to a copper smelter. The ingots produced run about 65% copper and, along with the pulps, they contain all of the other 20, or so, odd metals and PM's on the boards. These big 50# ingots have slag all over them, which must be removed. The needle gun worked the best for this purpose. These are the only ingots I have ever used the needle gun on.

I haven't read Ms.Hoke for awhile but, if I remember right, she used HCl to get rid of the iron from the ferrous sulfate she used to drop the gold. You and I don't normally use ferrous sulfate so, why use HCl? I can't think of anything else that would be present for it to dissolve. I haven't done aqua regia for awhile and I told you I have to search my memory to recall how I did certain things. I'm 67 and the CRS, Can't Remember S_ _t, gets a little worse each year. Of course, I thought of the presence of chlorides in tap water and from the aqua regia. My mamma didn't raise no stooped kids. Since you reminded me, I remember rinsing with distilled water in between the tap water rinses and the nitric acid. I also remember testing the last rinse before nitric for chlorides, with silver nitrate.

On to different things. Refining isn't a one trick pony. Enough has been written on aqua regia refining for the novice to do it. The info is scattered but, it's just about all there. In 1989, I made a list of 250 refining topics to write articles on. Refining karat gold was only one item on that list. I still have that list. I was going to do a refining newsletter. I could probably double the list today. Only about 10-20 of these have been covered on this forum. On to bigger and better things!


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## aflacglobal

Yes please do go into the ultrasonic thing. I can see this now.
I Think.


----------



## lazersteve

I've repaired a ton of the control and oscillator boards for these rigs. The company that hired us to fix them used them for cleaning fuel injectors on engines. It's basicly just a high frequency (15-30khz), high power 'audio' amplifier circuit, noting too fancy. The tank was SS with a piezo element on it to excite the liquid. They put a lye solution in the ones I worked on. I may even have some schematics still laying around in my shop somewhere.

Steve


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## aflacglobal

I understand the working , even the design theory. No problem.

Now explain to me how this is used in the refing process. Get technical, i don't care. Hell i know it works for grand pa's teeth.
I won't to know the other. Who was it started this ? GSP do fill us in.

Ralph


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## goldsilverpro

That would sure be the way to do it, Steve. They cost an arm and a leg to buy. Another source is to find a freon vapor degreaser. Most of these had an ultrasonic driven pool of freon at the bottom of the tank. When freon went down, most of these were scrapped out. They are stainless and you usually find them in a scrapyard that specializes in stainless, like restaurant equipment. You know anything about these, Ralph?


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## aflacglobal

I'm not sure of the way it is used in refining. Let me explain. I have worked in many fields. Don't ask. The job just means more than the money. Trust me. 
But i have put together many systems , some of my own design. 
In the refining field. Hell no. 

But the same basically applies in all system designs. complicated or complex systems are nothing more than made up of other tiny systems or controls. Which are made up of ???? other dam controls. I know my systems , now you gentlemen are teaching me what i need to know to work on my next project. 

The experience and the chemistry.
When i worked for a defense contractor we had a batch cleaner that we would lower the parts into. M-16, grenade components, stainless parts.
It was lowered into a 6x6 well. About 10 ft deep . at the bottom it sit in a vat of acid. Don't know what it was, but i didn't want to at the time. I was a machinist makeing $ 28. hr . why it the hell would i want to play with acid.

The acid had a frequency modulator field made up of about 10,000 of these miniature things.
Around the top of the well was two rings one at the top. another 6 ft down.
From these rings they sprayed liquid nitrogen. To catch any of the vapors that rose from the well. Trust me these things turned acid in fog.

I understand that. But what about it's application in the refining process. Why use ? what would be its purpose. Please explain at quark and lepton
level if that's it.
Would it help. would it speed it up. Removes impurities.

Hell i got a vibrator. No not that. (for my back) lol.
Somebody stop this madness before i my brain reaches critical mass.
Danger will Robinson, danger.


Ralph


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## Harold_V

aflacglobal said:


> When i worked for a defense contractor we had a batch cleaner that we would lower the parts into. M-16, grenade components, stainless parts.
> It was lowered into a 6x6 well. About 10 ft deep . at the bottom it sit in a vat of acid.



What you just described is a vapor degreaser. You sure it was acid? They're generally charged with trichloroethylene. Adding ultrasonic to it would be the ultimate in cleaning. 

Harold


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## aflacglobal

YOU GOT IT !!!


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## Harold_V

I worked defense as well. I'm a retired machinist/toolmaker. 

We had just such a critter at Sperry. They're not held in high regard these days------OSHA doesn't much like them.

Harold


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## aflacglobal

i was in machinist school


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## Harold_V

goldsilverpro said:


> I'm going to bow out of this, Harold, with a few closing statements. These long argumentative posts are wearing me out and we both are saying the same things over and over



This entire thread has lost it's perspective. Bowing out "with closing statements" that challenge published and well accepted practice is hardly "bowing out".. (washing with HCL, for example) 

The question as asked was:



> Hello,
> I would like to know what I must add/change to a standard AR process to get pure gold after melting it. Most of the gold buttons I get are not completly shining and seem to have a very thin layer of impurties. How can I correct that ?
> Thanks



Your insistence that it's easy to precipitate 9999 gold doesn't address the issue, so unless you're prepared to disclose your method, so all of us can achieve your level of excellence, I, too, see no good coming from this as it stands. Turning it into a pissing contest about how well you can precipitate gold doesn't help the guy that wants to know how to improve his quality by the AR method. That was, after all, the point. I've done my level best to address that issue-----and have Hoke waiting in the wings as my reasons. You did read my comments about being a student of Hoke, I presume? :wink: 

Harold


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## AgAuPtRh

In nearly 30 years of being in the Wood/cabinets/furniture/architecture business -- I can remember only a handful of times when situations like this would arise. 

Here's my take and request. 

This here has been one the most informative threads so far, in my opinion, on the forum. up to a point !!!!!!!! 

Personally I don't care which one of you is "Right" --because more likely than not both of you are. I don't need to know who is "better" "more Better" "right about absolutely everything" or who is the top dog around these parts. And I'll tell you why-----------I came here to learn not to see who's best -- I didn't come here to pick sides for some kind of vote -- I don't spend what precious time I do have waiting to come in to this forum to see who WON. 

I'm a busy man -- Regular job, side work, another small business venture and at the same time studying and reading and testing to learn the Art of Refining. Some of my ventures/comittments will be completed/ended here in a couple of weeks which will allow me the time to really get in to the meat of this trade and start practicing/processing/refining. I've been preparing for this for some time. With loads of literature, chemical glassware, building my own furnace, and more.

I believe I have the capabilities to read whatever--Hoke, Smith, Brady, Rose, Amman, Humble, and make the right choice for my situation and needs, and trust that choice and decision. I don't need to have anyone thinking for me or deciding "what" I need to learn or "How" I need to learn it. I haven't seen once in reading Hoke, Smith, Rose, Amman or whoever that spends anytime at all needing to be right -- About Anything. They just confidently present their methods and let the reader decide. 

Certainly would be cool if it was the same here. 

That's my take.

Here's my request. 

If you two need to have a pissing match -- take it out back. You are disturbing the students. Or as I once heard from a friend 

Come down off of your cross and build a bridge -- so you can get over it. 

in other words---- do your business in private email to each other. That option IS open you know. 

That's my take


----------



## goldsilverpro

AuAgPtRh,

You're 100% right, of course. I wondered when somebody would speak up and I really appreciate your doing it. These things start out innocently and then they sort of snowball. On the surface, it looked like a "top dog" thing but, I don't think that either of us felt that way. It was sort of an intellectualism thing gone sour. We sort of dragged each other into it and learned how to push each other's buttons. Like I said, it snowballed. Harold may feel differently, but that's the way I see it.

Whatever the motives, I vow to never get into one of these situations again. I've been in 2 or 3 of them now, and they all have ended badly. They are time consuming, energy zapping, and annoying to the other members. I apologize. I seem to be apologizing a little too much lately and need to stand back and examine my motives. The more this stuff happens, the less the other members participate. This is very bad, because the 200+ members are the heart and soul of this forum. Without you guys, this forum is nothing. Forums are like a living organism and it doesn't take much to kill them.

Sorry again, guys. If I do this again, please call me on it immediately.

Chris


----------



## aflacglobal

Can't we all just get along ? LOL

It's natural to want to be the alpha dog.
After all where would we be without competition and free enterprise.
I guess we can all agree to disagree.

I still love all you guys the same.
I'm new at this, but i take everyone advise and then i make my own
well informed decision. I'll listen to anybody, then it's up to me.


Ralph


----------



## Paige

It sure is nice being the dumbest kid on the block. You know you're never gonna being fighting for the Alpha Dog spot. I immensely enjoy learning from all of you A.D.'s.

Paige

For me, there is no way but up! Thank all of you soooooo very much!!!!!


----------



## aflacglobal

True that, Tex.


----------



## Paige

Oooooooohhhhhhhhhhhh, got me. Thru the heart.

Pai
g
e


----------



## aflacglobal

:shock: :roll:


----------



## PhillipJ

> On rare occasion, when I'd re-refine, I'd have a touch of nitric still left in solution. The gold came down fine, but when it came time to wash the gold (with HCL), I'd get the slightest of dissolution. Stop washing after allowing it to boil for a brief period (to consume the nitric with the precipitated gold) and then ice the solution



I had this happen to me, on my 2nd refinement, 1st rinse, with HCL and water. The solution turned a little yellow. I precipitated it in the normal fashion and did not put it on ice, because I didn't know.

Is there any reason that the 1st rinse couldn't be done in plain water to avoid this?

Also. Does it really matter if the rinse is with HCL or nitric. As long as the end result is clean.


----------



## Harold_V

PhillipJ said:


> On rare occasion, when I'd re-refine, I'd have a touch of nitric still left in solution. The gold came down fine, but when it came time to wash the gold (with HCL), I'd get the slightest of dissolution. Stop washing after allowing it to boil for a brief period (to consume the nitric with the precipitated gold) and then ice the solution
> 
> 
> 
> 
> I had this happen to me, on my 2nd refinement, 1st rinse, with HCL and water. The solution turned a little yellow. I precipitated it in the normal fashion and did not put it on ice, because I didn't know.
Click to expand...


The ice addition may not be needed in your case. I precipitated with SO2, and know from doing so that the precipitation process is exothermic in nature. It wasn't uncommon for my solution to get hot enough to slow down, or even stop the precipitation because the heat wasn't being dissipated. By cooling the solution, that didn't happen. Often times I'd add ice to a solution that had quit precipitating, and would achieve an almost instant reaction, which I attributed to the cooling. If you add your precipitant to your solution by mixing it with water, could be you provided enough of a heat sink to do the same thing. Hard to say. I've been away from refining for a long time now, and I used the same system for years, so the other methods are sort of a stranger to me now. 



> Is there any reason that the 1st rinse couldn't be done in plain water to avoid this?



My initial reaction is to say that it might be a waste of time, but maybe I'm wrong. The purpose of washing in acids is to remove undesired substances, which we both understand. Water in and of itself would be rather poor at doing that, but the fact that there's a trace of nitric remaining may be enough of an offset. I really don't know-------but my personal choice would be to stay the course and wash with HCL. I did that in practice, although I'm not saying it's the best way to go. It worked for me, so that was reason enough to do it. 



> Also. Does it really matter if the rinse is with HCL or nitric. As long as the end result is clean.



That's a reasonable question------one that will answer itself if you give it a go. 

Talking about eliminating the chlorides is a lot easier than doing it. The slightest trace of HCL in your solution when you introduce nitric will be no different than a trace of nitric when you wash your precipitated gold with HCL. In either case, you'll dissolve some of your gold. 

Assuming you can fully eliminate the chlorides, from my vantage point it may be every bit as good as HCL-----until the drying process. If you don't force dry the gold, it will retain enough nitric to burn your skin. It's a lot less forgiving of being handled than is HCL. 

The point I've tried to stress right along is that unless your thing is experimenting, there are tried and proven methods to achieve the desired end. As long as you have the necessary chemicals at your disposal, there's no good reason to deviate from accepted practice. If you're a curios type by nature, and like to experiment, one of the things that you should do before getting too creative is to read a Merck Index and understand the compounds of gold and silver. Getting creative with either of them can lead to an early death. 

In Utah, where I lived, a person with a chemical degree managed to blow a wall out of a lab by experimenting with a gold solution. I don't recall the details now, for it was about 30 years ago, but that was reason enough for me to stick to the book. Not being educated, I simply don't think I'm smarter than those that went before me. 

I've posted this picture before. It is a portion of the last lot of gold I re-refined just prior to selling my refining business. Note the color. Also note that it required no pickle, and was not melted under a flux covering. I know, beyond a shadow of a doubt, that my method worked----and worked very well. 

No------I make no guarantee that it is 9999. That number is difficult to achieve----which is the point I've tried to make right along. 

Harold

Edit: added words for clarity


----------



## aflacglobal

All right now i'm just hungry.

Milk and spoon anyone ?

That looks good enough to eat. 8)


----------



## Paige

Beautimus!


----------



## Noxx

Here is two pictures of one gold nugget I made using Butyl Diglyme. It weights 2 grams. It seems to be very pure.

But there is a «hole» in the middle. It formed when I cooled it in water. Is there a way to avoid that ?

Thanks


----------



## lazersteve

Excellent Button Noxx!!!

I see the BDG served you well!

The hole is what's known as a 'pipe' and is a sign of high purity as is the bright shine on the button. You can avoid the pipe by slow and even cooling of the button.

Great job with the BDG. 

Steve


----------



## Noxx

Thanks my friend 

I'll try to update the tutorial as soon as possible, I took a lot of pics :lol:


----------



## lazersteve

If run out of BDG just let me know and I'll take care of you.


----------



## Noxx

No problem ! Thanks a lot.

I try to keep every single drop lol. For my two grams nugget, I only use 80 ml and I recovered about the same amount. And I don't plan refining more than a few grams at once. For the moment, I'm just refining my own gold, for fun, because nobody sold his gold to me .


----------



## AuMINIMayhem

aflacglobal said:


> Can't we all just get along ? LOL
> 
> It's natural to want to be the alpha dog.
> After all where would we be without competition and free enterprise.
> I guess we can all agree to disagree.
> 
> I still love all you guys the same.
> I'm new at this, but i take everyone advise and then i make my own
> well informed decision. I'll listen to anybody, then it's up to me.
> 
> 
> Ralph



Well said, Ralph.. my sentiments as well.. 8)


----------



## aflacglobal

Thanks


----------



## catfish

Hey guys:

I have just finished up a batch of gold that started out looking bad. It was black, very fine and spongy. I used the method that Harold has outlined in this post on purifying gold. I am waiting on some new cupels to melt it.

I followed all the steps as far refining in AR, boiling in Hydrochloric for 5 minutes, rinsing, then boiling in water for 5 minutes, then rinsing, boiling in Ammonium Hydroxide for 5 minutes, rinsing, boiling in water for 5 minutes, boiling in Hydrochloric again for 5 minutes, rinsing, and boiling for 5 minutes in water. After all this I put it back in AR again and redid the entire process.

Attached is the finished product. Notice the gold is very light brown, clings together, and falls very fast in water. When I get it melted, I am going to send it to my gold buyer and have it assayed. I think it will turn out good.

Please note, the gold is still in water when I took the picture.

My many thanks to Harold and his fantastic knowledge and him sharing it with us.

My hat is off to you, Harold.

Thanks,

Catfish


----------



## Noxx

You absolutely have very pure gold.
Good job !


----------



## AuMINIMayhem

WOW!!! Great job, man!  






"Catfish hits the books and goes for the gold."


----------



## lazersteve

Very Nice!!!!

Great Job Catfish and Harold!!


Steve


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## goldsilverpro

Great looking stuff. Is that a Corning Ware dish I see? I think you would be wasting money by having an assay done. I think the results would be meaningless. Fire assaying is the most accurate of all methods. It's accuracy is .02%, but only at the hands of an excellent assayer, running duplicate (or, more) samples. By the looks of the material, it's purity is likely out of the realm of fire assaying's accuracy.

At this purity, the only inexpensive way to determine purity is to look at the ingot. You want no discoloration (usually reddish), great brilliant color, well defined crystal, and a pipe (a hole).


----------



## catfish

GPS:

Yes that is a corning ware bowl. I buy them for practically nothing at garage sales. My wife will not let me use hers. They are great for washing gold powder, and other things, etc. They will handle a lot of heat; the only problem is that you have to watch the level of fluid in the bowl when you are boiling something, for you can loose valuable gold due heavy bubbling effect with a shallow liquid level.(Been there, done that, and got the T-shirt to prove it)

Cris, I guess I am somewhat confused on your recommendation of not having the gold tested by fire assay method. What method would you recommend? I want to achieve a very high quality of pureness of my gold.

I get test results back on all my gold buttons that I sell, but they are tested by fire assay method. They test fairly well but I would like to improve the end results, but need an accurate method to let me know when I get there.

Any suggestions, you can give me would be greatly appreciated.

Thanks

Catfish


----------



## jimdoc

Catfish,
I think he is trying to say this you are posting in the wrong section.
You don't need any help, you got your diploma dude!!!!!!!!
I can't wait to see those results myself.
Also lets see the ingot when you are done, and that should show
what GSP is talking about with the crystals and the pipe, what he is
saying is that is a sure sign of very high purity, and a fire assay
will be a waste of money, because you will be able to tell from the
appearance of the final ingot or button. He is saying that an experienced buyer will be able to tell from seeing your results how pure it is.
Unless of course you are curious about the results for your own records,
and proof of your diploma.


----------



## jimdoc

When you get to a certain point in your refining abilities
assays are like badges. You can be confident in saying this
when selling your gold;
Assay, Assay, I Don't Need No Stinkin Assay!!!!!!!
And this song should be goin' through your head;

http://www.youtube.com/watch?v=GdNh9f2Wwm0&mode=related&search=

Or if you are a rock'n'roll refiner this one;
http://www.youtube.com/watch?v=JTfHxqwYUMk

For you federale refiners;
http://www.youtube.com/watch?v=ROIIQkLWdVw


----------



## catfish

GSP:

Please disregard my last post.

I am out of here.

Talk to you later

Catfish


----------



## PhillipJ

Thanks Harold.

Here is what I got using your cleaning method. I ended up redoing my 1st nugget.


----------



## Noxx

Nice nuggets


----------



## Harold_V

AgAuPtRh said:


> I believe I have the capabilities to read whatever--Hoke, Smith, Brady, Rose, Amman, Humble, and make the right choice for my situation and needs, and trust that choice and decision. I don't need to have anyone thinking for me or deciding "what" I need to learn or "How" I need to learn it. I haven't seen once in reading Hoke, Smith, Rose, Amman or whoever that spends anytime at all needing to be right -- About Anything. They just confidently present their methods and let the reader decide.
> 
> Certainly would be cool if it was the same here.
> 
> That's my take.



And here's my take. 

You, sir, do not know enough about refining to know when you're reading good or bad information. If you were, you wouldn't be here looking, particularly when you claim to have a library that is more than adequate to teach you how to refine. One of the books you claim to have read provides virtually everything you need to know to refine precious metals that you're likely to encounter. If you'd have read it as you claim, you'd already have a firm understanding of what I have been talking about. You obviously don't. 



> Personally I don't care which one of you is "Right" --because more likely than not both of you are. I don't need to know who is "better" "more Better" "right about absolutely everything" or who is the top dog around these parts. And I'll tell you why-----------I came here to learn not to see who's best -- I didn't come here to pick sides for some kind of vote -- I don't spend what precious time I do have waiting to come in to this forum to see who WON.



Well, you damned well should care, because one of these methods will give you more grief that you may desire. If you don't care which one of us is "right", why don't you go elsewhere? You certainly lend nothing to the forum-----and you're muddying the water for those of us that are trying to be helpful. 

What you don't understand, and likely never will with your attitude, is that someone here is offering you information that can spell the difference between success and failure-----with the added benefit of discussing risks that can be avoided. Best of all, it's coming to you free of charge, at least from me. 



> I'm a busy man -- Regular job, side work, another small business venture and at the same time studying and reading and testing to learn the Art of Refining. Some of my ventures/comittments will be completed/ended here in a couple of weeks which will allow me the time to really get in to the meat of this trade and start practicing/processing/refining. I've been preparing for this for some time. With loads of literature, chemical glassware, building my own furnace, and more



Well, "busy man", you won't have to worry about me providing you any conflicting opinions. I certainly have no intentions of spreading pearls before swine. Now you can take advantage of the offer by the other party to buy the same information that, up to this point, had been coming to you free of charge. 



> If you two need to have a pissing match -- take it out back. You are disturbing the students. Or as I once heard from a friend
> Come down off of your cross and build a bridge -- so you can get over it. in other words---- do your business in private email to each other. That option IS open you know.



As is your option to ignore what has been posted. 

Understand this: I am not insecure with my position as a refiner-----and have no doubts about the credibility of the information I provide. When a contest such as this goes behind the scenes, nothing good comes from it for the readers. I am not the least bit concerned with proving my position, not to you, not to GSP-------there is no pissing match. I know of what I speak. 

This isn't all about you and your preferences, not as far as I'm concerned. This is about me spending my valuable time trying to help people that want help, all without strings attached. If you don't like the way I present my information, tough! Just pay attention to the mistletoe I have attached above my butt. 

Harold


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## champ110

phillip, how much does that gold weigh?


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## PhillipJ

Six and 12 grams Champ


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## AuMINIMayhem

damn.. right at a half ounce troy.. good job! (They're beautiful!)


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## Palladium

Replay


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## Paige

And again.


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## teabone

Padding posts ??? Is that legal ????


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## Palladium

Not padding post.
Just pulling good and outdate topics back to the top of the thread. 
This one is a classic by harold :wink: 
This is the thread that explains your washing procedures. 8)


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## Palladium

8)


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## Ignatz61

Harold,
I can't claim six 9's purity but thanks to advice/admonisment from Harold I slowed down and followed tried and true procedures for dissolving and washing my gold. The two buttons in the photo are before and after following Harolds advice. I haven't had it assayed yet but the last one I sent in was .9214 I know this one is better than that. And the next will be better still. Thanks Harold.


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## Harold_V

Ignatz61 said:


> And the next will be better still. Thanks Harold.


You're very welcome, but if you'd like another tip, washing will improve your gold immeasurably, but if you really want to clean it up, consider refining a second time. 

While I have no scientific evidence of what I'm going to say, everything I experienced indicates it's probably true. 

When you precipitate gold from a dirty solution, impurities are dragged down along with the gold. Persistent washing appears to remove the majority, but not all of the contamination. A second processing liberates the trapped contaminants. Only when I started refining my gold a second time did I see an improvement. 

If you choose to give that idea a go----do what you've been doing right along, stopping short of melting. After you've washed the gold well and rinsed it so it's free of acid or ammonium hydroxide, re-dissolve the gold for a second filtration and precipitation. I used to force dry mine to insure it was free of chemicals. I'd heat it in the beaker until it had quit emitting fumes. 

When you re-dissolve, use the formula of a (fluid) ounce of nitric for a troy ounce of gold, and no less than 4 fluid ounces of HCl per ounce. A few drops of H2SO4 will insure you don't carry lead through the process. 

This may sound like a lot of extra work with little benefit, but you'll easily be able to see what you leave behind after you've precipitated the gold, especially if you use SO2 gas. I routinely double refined my gold, and almost always ended up with traces of blue in the residual solution after precipitation. 

The second precipitation yields gold of excellent quality, due in part to very little in the way of contamination being dragged down. Regardless, use the same extensive washing procedure as you did previously. I think you'll be pleasantly surprised at the improvement. If that be the case, please post your results, so others will benefit by your experience.

Nice improvement, by the way. Thanks for trusting my advice.

Regards,

Harold


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## Platdigger

It sure is good having you on this forum Harold!
Randy


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## Harold_V

Thanks, Randy. Just trying to pass along to readers the things that came to me only by the school of hard knocks. 

Harold


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## wop1969

goldsilverpro said:


> Add 3 times it's volume of tap water. This dilution will precipitate about 99% of the silver as silver chloride




Will this trick work on AP or AuCl "AKA" HCL/Clorox




goldsilverpro said:


> To about 4 gallons of dilute aqua regia, add about 60 mL of battery acid and stir. This precipitates the lead.



and will this work on AP or AuCl "AKA" HCL/Clorox as well


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## butcher

silver is pretty much insoluble as a chloride in water ( if high acid and oxidizer slightly more soluble). so this is were letting solution sit or heating to lower chlorides and not using too much acid or oxidizer and adding water several volumes of water help to precipitate the silver,

lead is insoluble as a chloride in COLD water (more soluble if acidic high or oxidizer) lead is slightly soluble in boiling hot water,
lead sulfate is insoluble, hot or cold, this is where a few drops of H2SO4 (sulfuric acid) can help to get the lead out.

lead is not very soluble in acid peroxide it is usually not to acidic and if you havent used too much peroxide it settles to bottom. silver similar.

lead can be in the HCl / bleach, letting sit and adding water will precipitate it if contents are not too high, if you dissolved alot of lead adding couple drops of sulfuric will also help. silver will also precipitate when diluted and less acidic,

since silver and lead are insoluble as chlorides they wont hardly dissolve in solution of HCL. although with high oxidizer some will this is a contaminate we eliminate by lowering the oxidizer in solution and diluting with water etcetera, then after precipitating gold with washing proceedures, we still are after these contaminates, and sometime by 
re-refinining a second time.


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## AuMINIMayhem

this may be a dumb question, but by adding more lead and cupelling would you not be able to drag out most if not all of the lead values?.. :?:


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## wop1969

Butcher, would it be a good practice for me to take my AuCl filter it clear then add few drops of Sulfuric and filter soilids then dilute with water, let it sit and filter out whatever is on the bottom?
then precip, rinse and repeat.

My AuCl sometimes has white stuff that does not sink well, and sometimes it looks kinda grey, and the longer the AuCl sits seems the more whitish stuff, like somthing is preciping as the acidity goesd down from gassing off. Now, since I know their is only AU, CU, and solders going into my AP baths then it has to be either lead or silver from the soilder, Correct?


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## butcher

it can help to boil a little chlorides off or just let it sit for a day or so, if you have lead few drops of sulfuric can help remove it in later step,
filter, add water to dilute ( this also lowers acid concentration so the silver chlorides and lead will precipitate, if after a day you still see some white powder in a dilute solution add a little HCL or table salt to help precipitate the silver as chlorides, in this dilute solution it should not be salts of your acids you are seeing. it is pretty much similar for Aqua regia solutions


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## wop1969

Sounds good.

One thing struck me when you said salts from the acid, I did not know about that and I knowticed if their is whit stuff floating on the bottom nad I dilute it goes away instantly. Am I correct to say that would indicate it is acid salt?


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## butcher

table salt can be made from HCL + NaOH muratic acid and sodium hydroxide to make sodium chloride NaCl and H2O,
when you add sodium hypochlorite (bleach ) to HCL hydrochloric acid (Muratic acid), NaClO + HCL, you will also be making some table salt in solution,

any acid and a metal like sodium or copper when added together make salts of those metals the sodium metal salt is just one of the salts we put on our french fries or food, some salts are water soluble some are not, some are soluble in acids, and some are not,

hope this helps


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## wop1969

IT does TYVM

Now I feel confident that the white stuff is salt not silver but, for the sake of getting clean gold I will use dilution and drops of sulfuric to get out any silver or lead..


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## Barren Realms 007

GSP 
Could you please elaborate on this? You probably have some where but I haven't seen it. Also will this work in HCL/clorox solution as well?

_When it's finished, transfer to a clean bucket. Add 3 times it's volume of tap water. This dilution will precipitate about 99% of the silver as silver chloride. To about 4 gallons of dilute aqua regia, add about 60 mL of battery acid and stir. This precipitates the lead. Allow to settle. 

I'll go over the precipitation later. _


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## Palladium

8)


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## goldsilverpro

Damn, Ralph,

You keep bringing up this damned thread and I'm just trying to forget it :lol:


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## goldnugget77

I didnt have chance to read all of this thread but in the first few pages Harold is saying to dissolve the gold in AR
Thats the impresion I got 
Hoke always says to remove the base metals first with nitric.
I could be wrong about this
Is this trued
Tommorow I will read this more carefully


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## butcher

Yes Harold would advise removing base metals, sometimes when we discuss things we may start at a certain point, especially when the person we are talking to already has an understanding of basics, it takes books and books to cover all the details, and it is hard to write them all in one post.
Harolds post here is excellent advice, the washing technique is just great, this info is worth copying and putting up on the refining wall.


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## Irons

goldsilverpro said:


> Damn, Ralph,
> 
> You keep bringing up this damned thread and I'm just trying to forget it :lol:


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## markqf1

Wow, Lassie sure has changed her looks! :lol: 

Mark


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## MargueriteMingorance

Harold_V said:


> lazersteve said:
> 
> 
> 
> I'm sure I used enough nitric (70% Lab Grade). I even poured off the first batch and added more to be sure. I didn't get much more action. I think heating is the issue. Since I don't have a fume hood yet I do everything cold and just wait it out. As I've stated many times, I'm in no hurry.
> 
> 
> 
> 
> There were a few batches I ran that were difficult to process. In my case it was a matter of not having added enough silver, so the end result is much as you describe. Even with a hard boil for a prolonged period of time, there were occasions when all action ceased, yet the core of the material being processed didn't have the base metals removed.
> 
> What I discovered in that instance is that you're more or less between a rock and a hard place. The only thing that works with certainty is to melt any un-dissolved pieces along with an ample amount of silver, to lower the gold content. Seems like if you run the first results in AR to exclude the gold, by the time it has been removed, the silver exposed will have formed a hard crust and makes running the balance of the material in nitric next to impossible. Re-melting eliminates all the headaches.
Click to expand...


Have you tried hammering it out into a thin sheet? More surface area will stop the gold from blocking access to the silver and other base metals.


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## Harold_V

MargueriteMingorance said:


> Have you tried hammering it out into a thin sheet? More surface area will stop the gold from blocking access to the silver and other base metals.


I didn't consider that as a viable option. I ran my operation for gain, and couldn't spend that kind of time messing with the material when I could remelt, adding more silver, and have it back in acid in just a couple of minutes, with _no fear of loss_. 

I'm not suggesting it wouldn't work---it would---but chasing the splintered values and spending the time just made no sense to me. 

By the way, more surface area isn't why it works. It works because the inquarted material, now being thinner, is dissolved to the core before a hard, impervious crust can form, isolating the remaining material from nitric. The increased surface area just happens to be the result of thinning. 

Harold


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## MargueriteMingorance

What is the name of this EDTA product? What is its formula? Did you add the salt to the AR solution? perhaps the sodium in it took the place of the gold, while the EDTA held everything else in solution.


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## goldsilverpro

MargueriteMingorance said:


> What is the name of this EDTA product? What is its formula? Did you add the salt to the AR solution? perhaps the sodium in it took the place of the gold, while the EDTA held everything else in solution.



That's being pretty pushy. This is one of few things that I invented and consider valuable. I doubt that I'll divulge it on an open forum although I'm sure that Manuel will have something to say about that. If you really want it, I will consider selling this information to you. I am including it in a book that I am writing, but who knows when that will be finished.


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## MargueriteMingorance

Whoa, hey, sorry, didn't mean to step on your toes. I'm not a refiner, I'm not looking to pry out your secrets. I was just curious what the mechanism was. Do you think it was the sodium going into solution that did it? EDTA doesn't decompose back into the formeldehyde it is made from, as far as I can tell.


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## Lou

Sodium is way smaller than gold? How would they trade places? No, it must be a redox and a VERY specific one at that!


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## AndyWilliams

Wow, great thread. Definetely worth the read to see the dynamics of this blog so long ago! Moreso, I think I gained a couple (tens?) of gold refining IQ points in the process. Thanks much for the read, and I think this should come back to the top frequently. I know I need to read it a few more times too.


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## butcher

Bump thread.


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## FrugalRefiner

Seven pages deep. Time to bump it again.

Dave


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## mugwarh

great read everyone should read this thread its very good info


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## Richard NL

Bump thread


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