# AR Process not completing



## chawimac (Mar 31, 2012)

Hi All,

I am having problems getting the AR process to finish dissolving my gold. Here is what I am doing:

I am using technical grade chemicals, mixing 4 Parts HCI + 1 part HNO3. Nitric gets added in two batches. Heat is added after second nitric addition reaction subsides.
Gold comes from scrap jewelry that is melted and poured in water to obtain popcorn. Vacuum pin is obtained to assay material before processing.

The problem arises at the end of the process. The silver sludge left behind has about 5% gold! I can't seem to get it all out!

Below a picture is included of the small reactor I set up in my shop. (Reactor)

Next is a picture of the XRF of the material that goes into the reactor. (Input)

Also what the material looks like after the process. (Output in Reactor)

The final product. (Au/Ag Bar)

Assay of the final product. (Output)

Hmmm I reached my pic limit. Anyways, what I find is that when the input material is 8-9% silver the resulting sludge is very white. When it is closer to 11% silver it gets pretty black. At 12% or so I get this problem. I thought the max silver content for this process was 15%. I would love to hear everyone's opinion ans thoughts on this.

The silver sludge gets washed with water sever times, drained, mixed with soda ash and anhydrous borax in equal parts, melted and poured.

Oh BTW I have been warned before about being un-explicative, so you can reference my other post where I learned a ton about Nitric! 

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=53&t=13236 

Thnx!


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## Barren Realms 007 (Mar 31, 2012)

Did you inquart this with silver to bring it down to 6K and then run the shot from that in nitric to remove the silver, PD and any other base metals before running this material thru AR?


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## chawimac (Mar 31, 2012)

No.

Its a 2 kilo batch, not practical to inquart and should not be necessary.


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## Barren Realms 007 (Mar 31, 2012)

chawimac said:


> No.
> 
> Its a 2 kilo batch, not practical to inquart and should not be necessary.





> The problem arises at the end of the process. The silver sludge left behind has about 5% gold! I can't seem to get it all out!




Hmmm, well you know I realy don't know then. 

You might do a search on Steve's web site and find some information on your problem with silver chloride stopping your process because it covers your gold in a shell that the AR will not penetrate.


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## butcher (Mar 31, 2012)

Nice reactor. 
I do not know if this will help. I am assuming you have in-quartered the gold, made shot and have dissolved as much base metals in nitric as you could.
Is it possible the percentage of gold to silver ratio in this shot, how well the melt was stirred and how well they were mixed in that melt, and how well the nitric reacted to remove the silver, and what form the gold was in after the nitric parting (powders or pitted gold shot), and whether you crushed the clumps and reacted with more diluted nitric and heat in this stage to remove silver completely as possible, or rinsing afterwards, could this be a reason you are getting the results you are?

You may have left silver un-dissolved trapped by gold in this step of parting with nitric. Maybe size of shot, how long it reacted in nitric acid and heat used, or percentage of silver to gold ratio in the in-quartering stage here may change the results?

Silver chloride can be very fluffy, and can trap liquids easily; also it is possible you are dragging some gold down with the precipitation of silver, thick solutions full of chloride salts, cooling too quickly, (or the gold is not being dissolved into solution)?

But I am not sure if this silver (and gold), we are discussing was dissolved into the solution and precipitated out, or if it was un-reacted powders left in the bottom of your reaction vessel? 

If un-reacted powders (did not dissolve into the gold chloride solution of your reaction vessel during the aqua regia process) it could be here, that the silver (left from nitric parting stage), Has now protected the gold from being dissolved completely into the aqua regia, leaving silver and some gold in the bottom of the aqua regia reactor vessel?

5% gold seems a little high, in your photo of the silver the crystals are fluffy, I do have some questions, this fluffy silver chloride in the screen filter of your picture, is this silver and other powders that would not dissolve in your reactor, or were they dissolved and then precipitated back out of solution?

Were you using urea to neutralize the nitric, (more salts in solution) and how dilute are you getting your solution, before precipitating silver from your gold chloride solution, how fast are these solutions cooling after leaving the heat and pressure of your reactor? 

In my mind several different things or a combination of these can be the answer to your question.

Is all of the silver and the gold dissolving into solution, (silver in the nitric step), and (gold in the aqua regia step)?

Are these metals being precipitated from concentrated solutions, or how fast or what state the precipitants form, causing other metals to be entrapped into the crystals as they form?

Then also how are you rinsing the powders?

Seems like all I have is more questions? 
Sorry no real answers.


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## martyn111 (Mar 31, 2012)

I don't get why you think that inquartation isn't practical or necessary, but we won't argue about that.



chawimac said:


> The silver sludge left behind has about 5% gold! I can't seem to get it all out!



Have you tried 'cornflaking' your final silver output (95% silver + PGM's / 5% gold) and disolving in 50/50 nitric/ distilled water, the resulting black powder will be your gold, the silver nitrate can be cemented with copper


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## chawimac (Mar 31, 2012)

I did not inquart this material.

I don't mean to be stubborn, but if I inquart 2 kilos of gold (at 50.58 purity) I would have to add 2 kilos of silver. Now I need to run 2 batches not one. The chemicals used are very dangerous and would hate to do twice the work. Thus I fail to see the reasoning behind inquarting this type of materials.

The question was what the threshold is or should be as far as silver content in the alloy to prevent the silver chloride stopping the reaction. I was told by a refiner that it was 15% with AR. Not true I gather.

Obviously I now will re-process the silver to get the gold out, but am trying to avoid this and doing twice the work.

Butcher: The picture is not a screen filter, but the bottom of the reactor. You are seeing a heating mantle. The stuff there is what did not dissolve in the reaction. 

The solution gets flushed out about half hour after the reaction stops and then we add about double the volume of water. Sometimes we add ice if available but most of the silver is left in the reactor anyways. The gold that comes out from the process reads 99.6 in the XRF but there is a margin of error, so I think its a pretty good number for one run.

And yes I use urea, as in my stubborn head I fail to see why not. Even though I have been advised not to.

Thus the problem is at the end of the AR process not dropping or filtering. 

Thoughts?


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## martyn111 (Mar 31, 2012)

What is the source of your feed material?
If you don't want to inquart and you don't want to re process your silver then the only other option I can see is you increase the gold content of your feed material until you have reduced the percentage of silver to an acceptable level for AR digestion.


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## Geo (Mar 31, 2012)

chawimac said:


> I don't mean to be stubborn, but if I inquart 2 kilos of gold (at 50.58 purity) I would have to add 2 kilos of silver. Now I need to run 2 batches not one. The chemicals used are very dangerous and would hate to do twice the work.



if you have one kilo of pure gold, you would need three kilos of silver. maybe i misread, but if this is what you meant then disregard this.


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## its-all-a-lie (Mar 31, 2012)

Wouldnt it be cheaper to do the job with the correct process first? This way you dont have to refine the same batch more than one time and thus saving dollars. Doing the same thing over and over again and expecting different results is the definition of insanity, i thought we were refining?.


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## butcher (Mar 31, 2012)

chawimac, 
We will all do what we think is best. 
Maybe you could try using one of the other methods and see if you like the results better.

I am still in love with that reaction vessel it is cool.

You could also refine your silver in a cell and get the gold back there, but you would most likely need to re-dissolve it in nitric to bring up the purity first (or fool with replacing the electrolyte).


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## Palladium (Mar 31, 2012)

I have read this thread twice just to make sure I was getting it. You have been giving the answer you are looking for several times in this thread, but yet you refer to it as stubbornness. Your procedure is flawed. And what I mean by that is yes you can run high gold with a high content of silver but the results are exactly what you are experiencing now. When you run gold this way it always needs cleaning up and that usually means running and dropping it again then acid washes. I didn’t hear you describe any washing procedures that you may do to clean your gold up. Did you drop the lead out before you precipitated? Refining is not a one step procedure. Most processes require many steps to separate these metals. That’s why we use the inquarting method and it works 10 out of 10 times. Until you realize this you will do nothing but have problems and wonder why. I haven’t run the numbers but geo said about 3 kilos of silver to inquart. You said you was processing like 2 kilo’s of gold. With that much money can you really not afford that much silver. Plus it eliminates the silver chloride problem. The silver collects your palladium, platinum and other metals for recovery later. It sure much makes your job and process easier. But hey! Keep doing it that way if it works for you. Try the other route and guarantee you will not be sorry. I like your setup you have there.


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## NobleMetalWorks (Mar 31, 2012)

I like your reaction vessel also, what is it exactly? I don't have enough experience to be giving anyone, any advice on anything, sorry I couldn't help there. But I am very very curious about your set up. If at all possible, could you take some pictures when you have time and maybe explain it?


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## chawimac (Apr 1, 2012)

I will post another thread with the reactor, fume scrubber, the works.

As far as the amount of material to inquart, if you see the pictures of the XRF you will notice the material is about 50% gold. Thus to get it to 25% it would take 2 more kilos of silver. Correct? (its a 2 kilo batch!) The starting material is gold scrap.

From what has been posted the only possible error aside from the high silver content is perhaps not mixing the metal enough when making the popcorn.

Now I am curious why everyone seems to be against the whole idea of not inquarting? I don't know how refiners work but I have seen a couple and did not see any inquart (That I have seen!). So why the attacks of insanity at the process?

As far as the washes I only use water. I am not interested in 99.999 pure gold. Its easier to just buy it. Ironically my interest is in the silver, hehe. I sell the gold at a better rate when it is almost pure, save in silver. That is why I am processing this. I like silver and think its a better bet to save in silver than gold. (Please bicker about your disagreement about my investment philosophy in another thread.)

I tested for lead, none there. Thus I did not want to use yet another deadly chemical. (See the pattern? This stuff is seriously dangerous and when you use gallons of it the danger level rises exponentially.)

I tried the silver inquart process and it kicked my butt twice until I got a hang of it. Am not fond of it at all!! I have great respect for the nitric.

So back to the original question. What is the maximum percentage of silver in the alloy to prevent silver chlorides stopping my reaction?


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## Geo (Apr 1, 2012)

sounds like you need to set up a silver parting cell. the resulting silver (if done correctly) will be 99.99% so the 5% gold and other impurities will not matter as all that will be left behind in the anode slimes.


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## chawimac (Apr 1, 2012)

Siver Chlorides


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## Barren Realms 007 (Apr 1, 2012)

I feel that is more than 5% of te 2 kilos that is shown in the 1st photo. Why have to go back and process this amount a 2nd time when you can follow the suggestions given to you and found here on the forum and do it only once. Love the reactor also BTW. 8)


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## Palladium (Apr 1, 2012)

Well I don’t know how to help you if you won’t listen to reason. I’m not trying to be hard here I’m just pointing out the obvious. Yes you have seen other refiners use this process. I use the same type process when I am running karat with stones and such. I don’t use it when I’m running scrap with no stones. Why? Because it causes problems. Your already corn flaking so just adding silver to inquart at that point is no big deal. You said you like to collect the silver so for me it’s a no brainer to use that silver to collect the other metals and to make my job easier. Do you not see the reasoning in it? With all the trouble your having and the extra steps that are added because of the problems in your processing can you not see how taking the long way around can sometimes be the short cut your looking for? You’re going to have to learn to use these dangerous chemicals as you call it if you plan on doing any serious refining. Yes these chemicals can be dangerous, more dangerous than a gun is in untrained hands, but with the proper training and respect that gun can becomes a tool and not just an object of destruction. I don’t know what to tell you. Anybody else???


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## lazersteve (Apr 1, 2012)

Typically gold must be 18kt (75% Au) or better and have a high surface area to avoid the silver chloride coating you are seeing when using straight AR. The silver chloride will still form, but it should not trap as much of your gold as you are currently seeing.

You can process karat gold directly in AR if you atomize the material first as detailed in a previous thread (find with a search for 'atomizer'). You can still expect some of the gold to be tied up in the resulting silver chloride.

People inquart their karat gold so as to avoid the problems you are seeing. Silver is cheap and is recycled in the process. The silver also acts as a scavenger for your Pd and Pt in the karat gold.

As you have found, cornflaking is not providing you enough surface area to ensure extraction of the gold from the silver chloride crust. You'll need a method of increasing the surface area much higher than cornflaking to see better results. Atomizing is this method in my opinion.

Steve


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## samuel-a (Apr 1, 2012)

Yup... while scrolling down i thought the exact same things as Steve.

You need high surface area, you can achieve that cheaply with a high water pressure pump and large nozzle.
Situate the nozzle about 2-3/8" above water level at about 30° angle and pour slowly. Try to aim the drops into the jet, but just above where the jet meets the water. It will not atomize the metal, but will form relatively small shots.

Were i you, i would lose the Drip Tip and replace it with an anchor shape o/h stirrer.
You have plenty of ground glass joints to fit a spiral condenser to.

To summarize, to improve your process you need:
- More surface area to react.
- Vigrouse stirring.
- working at boiling temp'.

p.s - an addition funnel (for nitric) may come in handy as the reaction my be too fast and get out of hand.

edit:
p.s 2 - anyway you look at it, your AgCl and the resulting silver will have some gold reported in it. If you could press the AgCl, you will increase the recovery of gold significantly.


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## chawimac (Apr 1, 2012)

Thnx all for your input. Much appreciated.


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## Dr. Poe (Apr 2, 2012)

This may be something that one would want to ponder: When dissolving gold with some silver and getting the silver chloride precipitation if this action takes place in sufficient spectrum of light some of the exposed silver chloride is charged and prone to reduction to silver metal. Once reduced to metal the silver can occlude some gold by cementation. Once occluded, the gold is protected from aqua regia (by metallic silver) and remains in the silver/silver chloride mix. The remedy is obvious: Do the reaction either in the dark or under a red light. Back in 1968, we toned black and white photos with gold chloride in photography class in high school. Perhaps this may be the reason for gold remaining in your silver chloride mass. Dr. Poe


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## 4metals (Apr 2, 2012)

It is not uncommon for karat gold run in aqua regia without inquarting to leave gold behind in the chlorides. Do you know the assay of the silver in the starting bar? If the assay was much more than 7 1/2 % the silver chloride encapsulates some of the gold, the higher the silver assay, the more gold is retained in the chlorides. 

I see production refining lots with silver up to 9% processed in aqua regia in large tumblers and the resulting chlorides can run as high as 1% in the silver bars. If they allow the silver to go higher the retained gold can exceed 5%. Personally I would rather refine in the light and not worry about the silver chlorides reducing in the light as there will always be some gold in the chlorides. The silver bars recovered from the aqua regia refining are perfect feedstock for a silver cell. Recover .999 fine silver and your gold will be in the slimes.


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## Lobby (Apr 2, 2012)

Many of you mention gold and silver precipitating from the AR solution due to the solution being too concentrated. Is this correct?


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## 4metals (Apr 2, 2012)

Silver always comes out of aqua regia as silver chloride. Gold will come out of aqua regia when it gets saturated with base metals which effectively cement out the precious metals. This is often confusing. If you are dissolving gold in acid along with base metals and you have a positive stannous reading, then after adding more scrap you have a negative stannous reading, the gold has dropped from the excessive base metals. 

No big deal, simply decant the barren acid off the solids settled to the bottom and add more fresh acid.

Until you are accustomed to dealing with acids loaded with metals, it is a good idea to follow Harolds recipe to eliminate the base metals before cleaning up the gold.


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## Lobby (Apr 2, 2012)

Thanks.

The reason I ask is that I've had situations somewhat similar to the Original Poster where the "gold would not dissolve." Frustrating, to say the least.

This happened with the current batch. Several smallish pieces of metal wouldn't dissolve, yet when I added a button of 24k gold (as per Harold's suggestion), it reacted well. Hmmm.

I dropped the gold this afternoon. Will wash and melt tomorrow. The undissolved metals will be separately melted and analyzed. Let's see what I find out.


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## chawimac (Apr 3, 2012)

Here is the post that I am writing with pics of my setup:

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=61&t=13739

Thanks all for the help and hope the discussion follows the post as I have plenty of questions about equipment.


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## Lobby (Apr 9, 2012)

Lobby said:


> Thanks.
> 
> The reason I ask is that I've had situations somewhat similar to the Original Poster where the "gold would not dissolve." Frustrating, to say the least.
> 
> ...



My results were quite interesting.

Here's a pic of the undissolved gold. Note the 24k piece to dissolve the unreacted AR (ala Harold).







I picked the undissolved gold pieces off the filter paper and melted them. I couldn't help but pick up a little AgCl, so I added a bit of soda ash to the flux to convert the AgCl to Ag. 











Total weight of the pieces = 1.4 g 

31% gold, 69% silver, no Pt nor Pd (by XRF - thanks Dan Dement!)

This amounts to about 0.9% of the initial gold that was undissolved. Is a 1% undissolved rate typical? 


The batch I'm working on right now also had some left over gold. (I haven't collected it yet). Looks like this is a systemic thing with me.


Thoughts?


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## nickvc (Apr 10, 2012)

Well the mix of silver to gold seems a little low for dissolution in nitric and that's where I suspect your problem may be, the nitric hasn't reacted with these pieces, they may also have been shielded from it and when then put into AR the silver forms a chloride coat which stops the gold been dissolved. A second treatment with hot nitric might dissolve those pieces but it would take time and if time is important I'd simply remove any pieces left after AR and put into the next melt.


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## Lobby (Apr 10, 2012)

I had the same thing occur on the batch I'm currently working on: incomplete dissolution of the cornflakes, while a 24k nugget placed in the solution to finish off the nitric readily reacts. 

I'm starting to think that a percent or so of inquarted metal not dissolving in AR is normal and I should just plan for it.


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## Geo (Apr 10, 2012)

i agree with Nick, passivization occurs when a coating of silver chloride stops the reaction. it could be the mix of metals that your using to inquart.


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## Lobby (Apr 10, 2012)

Just regular old 925 sterling.


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## maynman1751 (Apr 10, 2012)

Are you sure that you are getting a thorough mixing of the silver and gold during the inquarting melt, stirring the molten metals with a carbon rod? You probably already know that if the metals are not mixed well it's possible for some of the shot to be too rich in gold to dissolve. Just something to think about!!!!


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## Lobby (Apr 10, 2012)

Getting ready to start Batch 8:






Stirring rod at the ready. Gold underneath, silver on top.


:mrgreen:


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## Harold_V (Apr 11, 2012)

Lobby said:


> Several smallish pieces of metal wouldn't dissolve, yet when I added a button of 24k gold (as per Harold's suggestion), it reacted well. Hmmm.


Most likely not a mystery at all. If you've read Hoke, you have a firm understanding of the effects of silver in gold alloy. I'll describe what it looks like, from which you may be able to draw a conclusion as to why your gold wouldn't dissolve. 

When a piece of gold has excessive silver content (I would suggest greater than 10%, or less, if you're working with ambient temperatures), when you apply AR, the free gold on the surface readily dissolves, and traces of silver that are exposed convert to silver chloride. If the percentage of silver is low enough, the silver chloride is shed, exposing more metal beneath the surface from which it came. However, when the concentration level is too high, it continues to form, but does not shed. Instead, it forms a hard inert coating that prevents acid from contacting the metal beneath. Even prolonged boiling won't penetrate the surface, which, more or less, becomes impervious. 

If you were to remove metal that has been so altered, you'd notice that it has a rather strange green/gray color. It can be processed by re-melting, adding a sufficient amount of silver (inquarted) so it can be parted successfully with dilute nitric, or it can be cleaned with ammonium hydroxide, then sent back to AR. However, if the pieces are large and thick enough, that isn't a solution, as the condition will repeat until all of the inner metal has been dissolved. It's a waste of time to not re-melt with silver. 

Harold


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## Lobby (Apr 11, 2012)

Harold_V said:


> Lobby said:
> 
> 
> > Instead, it forms a hard inert coating that prevents acid from contacting the metal beneath. Even prolonged boiling won't penetrate the surface, which, more or less, becomes impervious.



Thanks so much, Harold.

Looking at the pic of the particles on the filter paper again, the hard silverish crust on the gold is evident.

The batch I completed yesterday had incomplete dissolution in AR also: about 1 gram out of a total of 61 grams of gold: it looks like I'm maintaining about 1% undissolved gold. I'll quit worrying about it and just recycle that gold from the filter papers in the subsequent batch.

Is this a common occurrence? Did you have this occur often with your AR steps?


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## Harold_V (Apr 11, 2012)

Lobby said:


> Is this a common occurrence? Did you have this occur often with your AR steps?


Not common, no, but it did occur occasionally. Generally when I didn't hit the desired 25% gold content when I did my inquarting. I had a "rule of thumb" that seemed to work quite well, which was to weigh the incoming gold scrap, then add 110% of the weight with scrap silver. The only time I deviated from that was if there was a showing of dental gold included, at which time I'd add more silver to offset the typically higher gold percentage. On rare occasion, the silver content might be too low, so the nitric digest was difficult, and occasionally incomplete. On such (rare) occasions, I would re-melt, adding more silver. 

I did not have the luxury of identifying each piece that was melted. It often came in in large volumes, and, because I processed individual lots, there was no need for me to assay. I had no good way of knowing the percentage of gold, so there was room for error when I'd inquart. Do keep in mind, inquartation will work through a wide range, however, so unless you err on the side of too little silver, the material will always part. It's just that the remaining gold may crumble, making separation of the fluids from the solids a little more difficult. A nuisance thing, really. 

Harold


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## Lobby (Apr 11, 2012)

Hmmm.

You must have normally received about 10k scrap. 110% of scrap gives about 25% gold, if the incoming scrap is close to 10k. But if it averages 14k (admittedly higher grade scrap), then I calc that closer to 190% of scrap weight with Ag is required.

Since this is the gold I buy at my scrap biz, I typically separate the various karat gold. I then calculate an "exact" inquartation amount. As I'm pretty sure I'm stirring well enough, I'm probably going to try "infifthing" :mrgreen: instead of inquarting for the next batch. It would be nice if I just didn't have to add another step to my processing.


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## dtectr (Apr 12, 2012)

Maybe I'm tired and my pain pills haven't kicked in yet, but G-zus !
Chawimac - if you can't afford the additional silver, [unless you were left it and your too expensive glassware by a rich old uncle], (yeah - I read the other thread) - congratulations on wasting money on equipment and then pissing off the only ones qualified to pluck your ass from the fire!)
Maybe you've refined several troy ounces of gold, (or pounds of silver, since it turns you on more) - I haven't yet but what I have managed to recover, refine and sell is thanks to the presentation of millenia of knowledge here at GRF; so when I see someone get in trouble by ignoring simple explanations of more complicated processes, then beg for help, then ignore sound, acknowledged direction, then insult the individuals who try to politely put his stupid ass back on track - I find that I am at a loss for words, for once. 
My dad called it "spending a dollar to save 15￠". My grandfather said "Measure it twice and cut it (a board, in his case) once."
You have 2 options at this point, as I see it - 
1. Continue on in the foolish course you've been pursuing, with the results you've been realizing, or 
2. Accept the direction offered here in the spirit it was intended, and begin seeing the full potential of the stock you are processing. If that doesn't appeal to you, you could always send me your feedstock and let me process it, according to established procedures - who do YOU think will end up with more money at the end of the day?


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## nickvc (Apr 12, 2012)

Chawimac the point your missing when you say the big refiners don't use inquartation is that they use assays or xrf readings to make sure they don't have too much silver in the mix to cause the problems your having, the other point to remember is that that they need fast, very fast turnarounds of their materials and a little left over to be refined next time is no big thing to them compared to the huge amount of money that could be tied up for days on end. They run these processes day in day out so the material is rarely tied up for long if you are doing the same fine if not your wasting chemicals and time trying to copy them, you have been advised on the best course to take but seem reluctant to follow the advice, your choice but the people advising have been doing this successfully for years while you are struggling....does there seem to be any correlation between the two?


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## Harold_V (Apr 12, 2012)

Lobby said:


> Hmmm.
> 
> You must have normally received about 10k scrap. 110% of scrap gives about 25% gold, if the incoming scrap is close to 10k. But if it averages 14k (admittedly higher grade scrap), then I calc that closer to 190% of scrap weight with Ag is required.


Sorry, you're wrong about *everything*. 

Lets look at it like this:
I'm going to assume that the lot I received was only 14K.
I'm also going to talk about grains, so we can get down to fine details. 
I'm going to assume that the 14K I speak of is really not 14K, but likely 13.5 K, which is not unreasonable. 

Based on that, I'm going to assume that the gold content is 56%. That means that from the (troy) ounce of gold received, there is contained within 268.8 grains of gold. 
That means that it must contain 211.2 grains of silver and base metal. 

If I add 110% of the received weight in silver, I'd add 528 grains of silver to the 211 grains already present. That totals 739 grains of silver/base metal. Overall weight would now be 1008 grains. Divide 268 grains by 1008 and you get 26%, which is well within the acceptable parameters of inquartation (Anything up to 35% can work---it's just more fiddly). 

Do keep in mind that the metal received was almost never just 14K, therefore my formula worked perfectly well unless there was something mixed with the gold that didn't catch my attention. 



> Since this is the gold I buy at my scrap biz, I typically separate the various karat gold. I then calculate an "exact" inquartation amount. As I'm pretty sure I'm stirring well enough, I'm probably going to try "infifthing" :mrgreen: instead of inquarting for the next batch. It would be nice if I just didn't have to add another step to my processing.


A decision you may come to regret. 

Pay attention to what you're being taught and put your creative thinking on hold. Can you not see that you are ignoring the silver and base metal that is present? Follow my instructions and you will achieve success. Of that I'm pretty sure, considering it served me perfectly well for over 20 years. Why anyone would screw around with this stuff, checking each piece for fineness, escapes me. I had far better things to do with my time, such as process gold for the *12+ hours I spent in the lab each day*. 

Harold

*I'm *dead serious *about that statement. I worked minimum 12 hour days 7 days/week for the last couple years I refined. It took all of my time to keep current with incoming work.


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## Lobby (Apr 14, 2012)

Harold,

I can't tell you how much I appreciate your responses, not only to me, but to entire refining community. You've taught us so much.

One example is your advice on adding a 24k gold button to finish the AR reaction and deplete the nitric acid. Prior to doing that, I'd have left over HNO3, but since I've started that, bingo, no more problems.

I also marvel at the elegant solution you came up with for adding 110% of the scrap's weight in silver. As an extremely busy refiner, I can see how that calculation saved you a bunch of time. That 110% addition works extremely well with real world scrap. Sure, if one only had 10k gold, the resulting inquarted gold concentration would be closer to 20%, but one hardly ever processes only 10k gold. For real world scrap (mixes of 10k and 14k), your 110% rule is about right on.


My main business isn't refining, but scrap gold buying. The reason I segregate my scrap by karat, is so that I can track my yields. As I don't have an XRF, nor an assay oven, math is about the only way I can confirm how much gold I'm selling.

And since I've only processed about 10 batches to date (I just joined the forum in January), gold yield has been of paramount importance to me. 

My early batches were troublesome. If one searches for the early threads I started, you'll find some of the silly mistakes I was making. But starting about Batch 5, my yields have been spot on. Between 98% and 103%. (Why 103%? Because there's invariably gold in the silver I'm using to inquart).

This focus on yield (not gold purity) is what's driving me: to not lose gold when I sell it. Thus my posts in this thread (how to get complete dissolution of the gold in AR).

My Batch 9 bar:







99.9% + gold, by two different XRF's, one a refinery

Funny thing: if you follow Harold's gold cleaning procedures, you make pure gold. Imagine that. :mrgreen:


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## Harold_V (Apr 15, 2012)

Lobby and I have been talking behind the scenes, and I offered him my apology for being the curmudgeon I have become (which was reflected in my response), but I believe he now understands that my purpose was to attract his attention in such a way that he would gain a clear understanding that my 110% addition is particularly important for guys that inquart random batches of gold. The time wasted checking each piece becomes troublesome over the long haul. As he alluded, it's rare for a batch to be either all 10K, or 14K, which accounts for the percentage mentioned. In practice, it rarely let me down, and saved me countless hours of time. 

I have commented, on several occasions, how important it becomes for the home refiner to become recognized as a (quality) refiner. Because my primary customers were manufacturing jewelers, they were accustomed to the quality of gold I produced, therefore they were willing to buy surplus when it was available. I became the broker for sales---often selling gold that belonged to one customer, to another. I did this free of charge--the only stipulation being that each _had to be my customer_. I refused sales to others, due in part to the fact that I always sold for spot, normally never available for the buyer, and the best possible return for those hoping to sell. My profit came from having a reliable customer base. Give that some thought. 

Harold


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## CASACEO (May 15, 2012)

I must say I love this forum. I have been reading articles for hours and have learned so much. I too had little gold beads that were covered in blackness and didn't completely dissolve in AR. I had even previously sanded off the black residue to reveal gold (oops :evil: ) I am new and learning from my mistakes, and now from the mistakes of others. Thanks GRF community!!


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