Help with Nitric Acid Elimination

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briguy2112
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Help with Nitric Acid Elimination

Post by briguy2112 » June 3rd, 2010, 6:23 pm

So I made my AR, and roped my gold in. I ended up with a greenish yellow liquid. I filtered it like 5 times till all I had was the liquid. So I start to add Lye to neutralize all the Nitric acid. I had to keep adding it a spoonful at a time. I must have added about 2 cups before it stopped fizzing. Now I have a very cloudy white powder on the bottom of the bucket. Is there any way to fix this? I tried filtering and still have it there. If I add the SMB will it destroy all the gold getting mixed in with the left over lye? Please help. Also the AR turned a very royal green color and not yellow. Does that mean I have a lot of copper and will that precipitate out with the gold? I have been reading posts all day and cannot find the answer. Thanks to all of you for contributing to this very informative forum.

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Re: Help with Nitric Acid Elimination

Post by butcher » June 3rd, 2010, 6:34 pm

NaOH + HCl ---> NaCl
NaCl = table salt

there are better ways to get salt for your fries.

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Re: Help with Nitric Acid Elimination

Post by samuel-a » June 3rd, 2010, 7:58 pm

can gold drop down as hydroxide by addition of NaOH?
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Re: Help with Nitric Acid Elimination

Post by chemist » June 3rd, 2010, 9:25 pm

Why did you add lye to neutralize the nitric acid? The lye would also react with the hydrochloric acid (as butcher noted).
Normally the nitric acid is destroyed by evaporation or addition of urea. The HCL need not be neutralized prior to precipitation.
The green is probably due to copper. When you precipitate with SMB some of the copper will be mechanically dragged down, but not much. The final powder should have less than 1% copper. You will need to redigest with AR and reprecipitate to get high purity gold.

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Re: Help with Nitric Acid Elimination

Post by briguy2112 » June 4th, 2010, 12:09 am

chemist wrote:Why did you add lye to neutralize the nitric acid? The lye would also react with the hydrochloric acid (as butcher noted).
Normally the nitric acid is destroyed by evaporation or addition of urea. The HCL need not be neutralized prior to precipitation.
The green is probably due to copper. When you precipitate with SMB some of the copper will be mechanically dragged down, but not much. The final powder should have less than 1% copper. You will need to redigest with AR and reprecipitate to get high purity gold.



Can I use baking soda or anything else I can't seem to find Urea anywhere locally. They have fertilizer with urea in it but it has a bunch of other crap too. Or can somebody tell a different name it may be under? Or another product I may use? Thanks again for all the help. Also is this 1st batch shot? I am just doing little batches trying to get it right, so its not a big deal if it is. I am using 1/10 gold filled items per batch and using 1 pound of it at a time. I have another batch ready in AR for tomorrow. and another for Saturday. Please let me know.

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Re: Help with Nitric Acid Elimination

Post by Barren Realms 007 » June 4th, 2010, 12:18 am

briguy2112 wrote:
chemist wrote:Why did you add lye to neutralize the nitric acid? The lye would also react with the hydrochloric acid (as butcher noted).
Normally the nitric acid is destroyed by evaporation or addition of urea. The HCL need not be neutralized prior to precipitation.
The green is probably due to copper. When you precipitate with SMB some of the copper will be mechanically dragged down, but not much. The final powder should have less than 1% copper. You will need to redigest with AR and reprecipitate to get high purity gold.



Can I use baking soda or anything else I can't seem to find Urea anywhere locally. They have fertilizer with urea in it but it has a bunch of other crap too. Or can somebody tell a different name it may be under? Or another product I may use? Thanks again for all the help.
No don't use the baking soda.

Urea is the perticular name of the fertalizer, just like ammonia nitrate, sodium nitrate & potassium nitrate. It will not take as much as you think to neutralize the nitric in your solution. Just depends on how much you have. Got to a specialty garden store, corner flower store, just look for a small place that sells plants and shrubs and you can ask them where you can find urea or other small garden stores.
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Re: Help with Nitric Acid Elimination

Post by Noxx » June 4th, 2010, 1:56 am

chemist wrote: Normally the nitric acid is destroyed by evaporation or addition of urea.
I'm sorry but that's not the case. Urea will remove NOx in solution but not nitric acid. In fact, you can add a handful of urea to red fuming nitric acid to make it "white".

If you want to neutralize an acid, you need a base.
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Re: Help with Nitric Acid Elimination

Post by Harold_V » June 4th, 2010, 3:43 am

Funny. I processed gold, using AR, for more than twenty years. Never, ever, did I use urea. NEVER!

Have you given any thought to evaporating? Seems to work. It's in Hoke's book.

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Re: Help with Nitric Acid Elimination

Post by briguy2112 » June 4th, 2010, 2:36 pm

Harold_V wrote:Funny. I processed gold, using AR, for more than twenty years. Never, ever, did I use urea. NEVER!

Have you given any thought to evaporating? Seems to work. It's in Hoke's book.

Harold
How long should I heat it for? I know from reading the forums NOT to boil it. But how long do I need to keep it heated, and how do you know when all the Nitric is gone? Thanks again all for helping this newbie out :D

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Re: Help with Nitric Acid Elimination

Post by philddreamer » June 4th, 2010, 3:24 pm

Hi briguy2112!

Go to "Gallery"; click post "13gm gold slug", download "inquarting" attchm'nt.

Read it. The answer is there.

Have a good one!

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Re: Help with Nitric Acid Elimination

Post by Harold_V » June 5th, 2010, 4:51 am

briguy2112 wrote:How long should I heat it for? I know from reading the forums NOT to boil it. But how long do I need to keep it heated, and how do you know when all the Nitric is gone?
Again, that's all in Hoke, but if you want my slant on the subject, you heat the solution at a low heat, so it slowly evaporates. The admonition to NOT boil is spot on. If you evaporate too quickly, you lose values, something I learned the hard way. Losing the gold wasn't enough, it ended up on the side of my travel trailer, turning the area purple.

So then you heat slowly, allowing the solution to concentrate. Note that as the volume decreases, the temperate can rise, particularly if you are using an evaporating dish.

As the solution gets concentrated, you witness a color shift. If you are working with a relatively clean solution, it will go from orange to red, to a dark brownish red. If you evaporate too far, you can precipitate some of the gold, so don't let it get past a dark red/brown color. You introduce a little HCl, which will help eliminate the excess nitric. If you have done your work well, there will be very little present, and, assuming you have concentrated the solution adequately, when you introduce the HCl, you will see brown fumes emanate from the gold solution. That's the nitric being expelled. Do this three times, or until when you add HCl, you no longer see any fumes escaping.

Again, please read Hoke. All of this has been well documented.

A trick I used, and used for years, with excellent results, was to add a button of gold to the gold chloride solution when I started evaporating. That way, as long as you maintain a little free HCl, any nitric that remains will be consumed by dissolving the gold button. That way you can eliminate the repetitive evaporation and HCl additions. Do remember---if the solution is lacking in free HCl, even though there may be some free nitric present, it won't be expelled. So then, insure there's free HCl present at all times. It does no harm, aside form making it harder to filter without your filter failing. That problem can be addressed simply by diluting the solution well before filtration.

Luck!

Harold
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Re: Help with Nitric Acid Elimination

Post by chemist » June 5th, 2010, 6:44 am

Noxx wrote: I'm sorry but that's not the case. Urea will remove NOx in solution but not nitric acid. In fact, you can add a handful of urea to red fuming nitric acid to make it "white".
If you want to neutralize an acid, you need a base.
I will take your word for it since I am not an expert on the urea method. I always thought that the urea reacted with the excess nitric acid. If all it does is force out the NOx, what use is it? It would seem that a hot solution can't have very much NOx dissolved in it for very long.
I certainly recognize that a base (lye) will react with an acid to form a salt, but I have never seen anyone here refer to neutralizing the nitric acid that way.
I like the method described by Harold. Reaction with a 24k button during evaporation has always seemed to be the easiest method to destroy any excess nitric acid in the solution.

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Re: Help with Nitric Acid Elimination

Post by lazersteve » June 5th, 2010, 9:55 am

Chemist,

I have adopted a mentality that if you don't add too much nitric when dissolving your gold, it won't have to be removed in the end.

The keys to this approach are first to do some preliminary math on the required amount of nitric to dissolve all of your material, and second to add the nitric in small increments until the metal is totally dissolved. This is something I learned from GSP. I've used Harold's method also, but I prefer not to add the excess acid in the beginning.

I have not had problems with excess nitric in my solutions since adopting this methodology. I don't evaporate, use urea, or add extra gold. I simply add SMB and the gold precipitates. On rare occasion, if I have a slight excess of nitric due to the fact that I could not determine the actual amount of required nitric by calculation, the SMB will foam up and release the brown fumes. For this reason I always fill my beaker no more than 2/3 full of pregnant solution. I also keep a spare empty beaker of equal size on hand in case I have a large foam over. The precipitation is also done with the primary beaker in a flat white corning ware casserole dish.

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Re: Help with Nitric Acid Elimination

Post by Harold_V » June 6th, 2010, 2:19 am

GSP's recommended method of using only the amount of nitric that is required to do the job is great advice. Problem is, you rarely know exactly how much gold you have present. It is also time consuming to allow acids to work until they are totally exhausted. Not an issue if you are hobby refining, but when I processed for gain, time was everything. I ran behind almost constantly, and could ill afford to allow beakers to sit for hours, hoping to wrest the last bit of nitric from a solution. It makes good ecological sense, but does not make economic sense, not on a commercial basis, especially when you purchase nitric for $4/gallon.

Armed with my comments, above, you can clearly see that when you approximate the amount of gold present, and use a corresponding amount of AR, you will be very close, and accomplish the mission in short order. If there is extra nitric, that insures a speedy dissolution. Adding a button afterwards, during evaporation, takes little time, and is 100% effective in eliminating the free nitric. Do consider that I processed with concentrated solutions, so evaporation was an expected part of the operation. For the record, it was unusual to dissolve more than a quarter ounce of added gold. You get quite good at estimating the content after years of handling the material.

Were I to refine today, I would avoid using urea.

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Re: Help with Nitric Acid Elimination

Post by briguy2112 » June 6th, 2010, 10:28 am

ok Batch 2 a total bust also. I am working with 8 oz of filled and plated jewelry. I am using 300 ML of HCl and 100ml of Nitric. I let it sit for 2 days i added about 100ml more AR after day 1. I end up with a dark green, black solution. I filter it about 4 times to get all the solid material out. I then did the reduce via heat. I added about 100ml more HCL to get all the solids clean. So I had about 400ml of liquid. I reduced it down to about 200ml and then added more hcl to back to 400ml. reduced again, add more hcl to 400. then on the third time I reduced it down to about 150ml. There was a sivelry film on the top and a powdery substance on the bottom. I let it cool for about 6 hours or so, I added about 500ml of distilled water It turned a light green. Then I filtered it like 4 times . I added about 10 grams of SBM in 2 gram increments, but no gold to be seen. No mud, and no gold spongy material. Where did I go wrong? I know there was gold in the material. It was all marked 14k ge or 1/10 GF. I need advice before I try the 3rd batch. I envy all of you that worked to get this process down, because the theory and the practice is 2 totally different thing. Thanks again everyone.

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Re: Help with Nitric Acid Elimination

Post by philddreamer » June 6th, 2010, 10:50 am

Brother bri, you haven't been read'n. If you would have read you would know that the best way to recover gold GP & GF items is to use lazersteves sulphuric cell. Go to his website & watch the video; over & over, before the 3rd batch! You have a big mess in your hands & is 'cause you didn't do your home work! :lol:
Slow down, I know how you feel, anxiuos. Be patient & learn "why" it has to be done "this" way, & NOT "that" way. There's a reason. I made the same mistake; trust me, read.

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Re: Help with Nitric Acid Elimination

Post by lazersteve » June 6th, 2010, 11:15 am

Harold_V wrote:GSP's recommended method of using only the amount of nitric that is required to do the job is great advice. Problem is, you rarely know exactly how much gold you have present. It is also time consuming to allow acids to work until they are totally exhausted. Not an issue if you are hobby refining, but when I processed for gain, time was everything. I ran behind almost constantly, and could ill afford to allow beakers to sit for hours, hoping to wrest the last bit of nitric from a solution. It makes good ecological sense, but does not make economic sense, not on a commercial basis, especially when you purchase nitric for $4/gallon.

Armed with my comments, above, you can clearly see that when you approximate the amount of gold present, and use a corresponding amount of AR, you will be very close, and accomplish the mission in short order. If there is extra nitric, that insures a speedy dissolution. Adding a button afterwards, during evaporation, takes little time, and is 100% effective in eliminating the free nitric. Do consider that I processed with concentrated solutions, so evaporation was an expected part of the operation. For the record, it was unusual to dissolve more than a quarter ounce of added gold. You get quite good at estimating the content after years of handling the material.

Were I to refine today, I would avoid using urea.

Harold
You are correct Harold, there is a distinct difference in the amount of time required to perform the incremental process. When I'm in a pinch for time I tend to use your method on occasion.

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Re: Help with Nitric Acid Elimination

Post by goldsilverpro » June 6th, 2010, 1:09 pm

Harold,

I think you knew that I would have to put in my 2 cents worth on this subject.

There are several ways to successfully refine karat golds. Let me preface this by saying that I truly believe that your method of inquartation and, finally, boiling down is the absolute best method for the members of this forum to use. The reason being is that, if they follow your instructions, this method will work each and every time. For this reason, there will be less frustration for the beginners. Also, since you had to satisfy your customers, I think that your choice of method was the best. However, since the gold I worked was already mine, I never inquarted or boiled down and never will. And, I would bet that our final products were equally pure. Also, I have very successfully used the "minimum amount of nitric" method for 30 years and I don't think you would put me into the category of a hobby refiner.

To everyone else, here's a little of my history and the history of this method:

(1) My first true experience in big time refining started in 1968, when I was hired as Senior Chemist for a new refinery in LA. At that time, this was the largest gold refinery West of the Mississippi. This same company was also the world's largest seller of precious metals plating systems. I was in charge of manufacturing the plating solutions, routinely analyzing and troubleshooting plating systems for our some 1500 customers, assaying refining lots (about 100 fire assays per day), and developing refining systems. Since we were using the refined gold to make plating salts, the necessary gold purity was 9999. At first, the company had big problems producing this purity. They were using AR, ferrous sulfate or SO2, and Wohlwill cells. They didn't want to inquart or boil down because of the time involved and the additional dissolving equipment that was needed.

For about the first six months, our gold was only pure enough to sell - about 9995. To make the plating salts, we had to buy expensive 9999 gold on the open market. Most of the gold we were refining (usually powder) came from processing electronic materials and the workers used premixed AR. I eventually discovered a unique chelating agent that would drop 9999 gold. It actually worked better with a lot of extra nitric in the AR and it chelated the base metals, kept them in solution, and prevented them from contaminating the precipitated gold. This eliminated any need for inquartation, boiling down, or Wohlwill cells. At that point, my method was adopted and was used to refine hundreds of thousands of ounces of 9999 gold, over a period of several years.

The chelating agent was expensive, however, and, it could have been eliminated or reduced, had I known about the "minimum nitric" (and, purifying in the melt) method at that time.

(2) I started my own refinery in about 1972 and used the chelating agent to drop the gold. In 1979, I went to work for a guy that used the "minimum nitric" method. He and David Fell were childhood friends and had worked together for the largest karat gold refiner in LA - where they learned the business. I don't know if Dave also used the method or if my boss had invented it. I do know that I have never heard of any other refiner using it and have never seen it in print. My boss used twelve 4 liter beakers (each with a cover and attached exhaust hose that took all the fumes to a manifold and then to a scrubber) to dissolve the gold and, in 1979-1980, we had so much karat gold scrap that the 12 beakers were always being used. We also sometimes used a 50 gallon glass-lined, steam-heated Pfaudler kettle, when we were over-burdened with too much scrap for the beakers.

His method was to first cover the karat gold jewelry (as is) with HCl and heat it. Then, he would add a splash of HNO3 from a gallon jug and let it react. This was repeated until an addition of HNO3 produced no reaction. At this point, either it all was dissolved or more HCl was needed. He would then add more HCl. If nothing happened, it was finished. If the HCl produced a reaction, he let it work until the reaction subsided and then added more nitric. He used the HCl and HNO3 separately, back and forth, until there was no reaction from an addition of either. He never estimated or measured either acid, yet never overshot the nitric. He had done this so many times, he just knew, by looking, when he had added the right amount. He dropped the gold with sodium sulfite and cleaned the gold with fluxes in a gas crucible furnace. If he couldn't get the gold to at least 9995 (maybe 5% of the lots), he used a big set of 6" rolls to roll the bar super thin and then quickly redissolved it in AR. From start to finish, the gold was always done in one day - usually 8 to 5.

Anything that didn't dissolve in the AR (maybe 5%) was accumulated and treated separately at a later date. He had a quirk that he didn't want anyone to rinse the yellow out of the filter papers. They were accumulated and burned and the yield was used to throw a party. Since all the gold was already bought and paid for, he didn't have to satisfy anyone as far as the yield was concerned. It was a fun place to work.

(3) When I owned my next refinery, I started estimating the amounts of acids needed. This was mainly done to make sure I had an excess of HCl to start with. That way, I didn't have to do the back-and-forth thing with the acids. When an addition of HNO3 produced no reaction, I knew it was finished. For karat gold, instead of using the customary 120 ml of HCl/ounce, I used 150 ml. I didn't worry about the nitric, since I was good enough by then to know when I had added exactly enough. I usually measured it out into a beaker, though, as a precaution against having a brain f**t and dumping in too much by adding it straight from the jug.

(4) To use the "minimum nitric" method, you should keep these things in mind:

(a) Any mixture of HCl and HNO3 will dissolve gold. You don't need 3 to 1 or 4 to 1 AR. As an example, for one certain type of application, I always used a 50% Nitric/45% water/5% HCl to dissolve the gold.

(b) When dissolving a quantity of metal, both the HCl and HNO3 are consumed at definite rates for each. In the case of gold, when only one of the acids has been totally used up, the dissolution of the gold will cease.

(c) For dissolving gold or gold alloys, I haven't pre-mixed aqua regia for the last 30 years and will never do it again. When you pre-mix it, it is very likely that you'll need to use urea or to boil-down, both of which I have a tremendous aversion for.

(5) I'm not going to go into details on using this method, since I have gone over it many times on this forum. All I will say is that it is simple and fast (especially when the alternative is boiling-down) and it works. Like Steve just said, you just have to adjust your mentality.
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Re: Help with Nitric Acid Elimination

Post by machiavelli976 » June 6th, 2010, 2:26 pm

nice one ! should be read by all new members and not only. i shall move the post below the board policy. great spare of time for everyone! :P

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Re: Help with Nitric Acid Elimination

Post by chemist » June 6th, 2010, 3:48 pm

I am but a small grasshopper attempting to drink from the fire hydrant.......

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Re: Help with Nitric Acid Elimination

Post by 4metals » June 6th, 2010, 9:10 pm

I constantly face a situation where the client wants to refine gold, mostly from jewelery scrap. Again they are paying on assay so inquarting is not used as any gold remaining in the chlorides is recovered in the reduced chlorides bar. But these guys are not chemists, and they need a number. I can't tell them to do what GSP just explained, they want a concrete number.

So I have to give them a number, the number I work off of is 1 liter of acid will digest 7.5 troy ounces of karat scrap, any karat. I then tell them to make up acid at a ratio of 4:1. So if you have 7.5 ounces, divide 1000 by 7.5 and come up with 133.3 ml per ounce, total acid. Divided by 5 gives you 26.6 ml for Nitric and times 4 gives you 106.6 ml Hydrochloric. This number proves to be close, and generally provides a good digestion. (If silver is under 8%) Often when doing diamond removal, the scrap is not melted first (for obvious reasons) and some pieces stubbornly resist digestion. I have found that after the acid has had a good boil and is no longer blowing red, an addition of 10% of the startup Hydrochloric will again kick off the nitric reaction and result in a more complete digestion. Kind of counter intuitive to add HCl to get the solution to blow red again, but it's the free HCL that matters here.

These guys always have nitric left over after digestion. It's a production environment and often some of these guys have "refiners" who aren't the sharpest crayons in the box. If they haul their wastes, I suggest adding urea prills. If they treat their waste, I do not. Then we gas with SO2 and gas off the nitric. Never do they boil down to remove nitric.

If there were an easy works every time formulation to use I would use it, but I think for the most part the readers of this forum are better informed and more responsible and capable of not using too much nitric and that is the best approach, as masterfully spelled out by GSP.
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Re: Help with Nitric Acid Elimination

Post by briguy2112 » June 7th, 2010, 12:42 am

philddreamer wrote:Brother bri, you haven't been read'n. If you would have read you would know that the best way to recover gold GP & GF items is to use lazersteves sulphuric cell. Go to his website & watch the video; over & over, before the 3rd batch! You have a big mess in your hands & is 'cause you didn't do your home work! :lol:
Slow down, I know how you feel, anxiuos. Be patient & learn "why" it has to be done "this" way, & NOT "that" way. There's a reason. I made the same mistake; trust me, read.

Have a good one brother!

philddreamer

I watched every vidoe in there. Are you talking about the antiquating method?

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Re: Help with Nitric Acid Elimination

Post by philddreamer » June 7th, 2010, 1:03 am

Do you mean "inquarting"? No, that's for karat gold; you melt 25% gold/ 75% silver. Its the video of the gold sulphuric cell. Here is a photo of mine.
You use it to de-plate the GP & GF items with it.
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Re: Help with Nitric Acid Elimination

Post by briguy2112 » June 7th, 2010, 8:31 am

awesome video now after this would I do the same SMB method to extract the gold from the liquid of the cell?

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Re: Help with Nitric Acid Elimination

Post by lazersteve » June 7th, 2010, 8:57 am

Here's how to proceed starting with a full cell:

Black Powder from Cell

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Re: Help with Nitric Acid Elimination

Post by shyknee » June 7th, 2010, 9:40 am

briguy2112 wrote:ok Batch 2 a total bust also. I am working with 8 oz of filled and plated jewelry. I am using 300 ML of HCl and 100ml of Nitric. I let it sit for 2 days i added about 100ml more AR after day 1. I end up with a dark green, black solution. I filter it about 4 times to get all the solid material out. I then did the reduce via heat. I added about 100ml more HCL to get all the solids clean. So I had about 400ml of liquid. I reduced it down to about 200ml and then added more hcl to back to 400ml. reduced again, add more hcl to 400. then on the third time I reduced it down to about 150ml. There was a sivelry film on the top and a powdery substance on the bottom. I let it cool for about 6 hours or so, I added about 500ml of distilled water It turned a light green. Then I filtered it like 4 times . I added about 10 grams of SBM in 2 gram increments, but no gold to be seen. No mud, and no gold spongy material. Where did I go wrong? I know there was gold in the material. It was all marked 14k ge or 1/10 GF. I need advice before I try the 3rd batch. I envy all of you that worked to get this process down, because the theory and the practice is 2 totally different thing. Thanks again everyone.
I reread your post ,and it is obvious you did not go to completion and removed the values when you filtered(hope you did not throw it out).

you should always remove the base metals first then use AR.

You will have to process your filters and solids to get at the values
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Re: Help with Nitric Acid Elimination

Post by briguy2112 » June 7th, 2010, 3:18 pm

ok so after I reduce and add hcl and reduce again and add more hcl. then I filter and add 4x distilled water, what color should I have? I seem to have a very light green to blueish color. It this correct? All the vids and post list you end up with a yellow liquid. I don't want to add the SMB if this is wrong. I am sorry for being such a huge newb at all of this, but I am learning LOL. Hope I don't spend a fortune to do it tho. I made a pretty cool Fire brick smelter that I will post pics of when my wife tells me where the camera is. Lazer Steve when I grow up I wanna be just like you :D

P.S. I the cell method do you make the positive side just like you made the negative side with the lead? only it does not go into the liquid?

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Re: Help with Nitric Acid Elimination

Post by lazersteve » June 7th, 2010, 4:21 pm

Don't go by color, go by a stannous test. If the stannous test positive, you have gold in the solution.

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Re: Help with Nitric Acid Elimination

Post by briguy2112 » June 7th, 2010, 6:19 pm

lazersteve wrote:Don't go by color, go by a stannous test. If the stannous test positive, you have gold in the solution.

Steve

Cool I did that and it tested positive. So I mixed about 8 grams on SBM in hot water to dissolve. I dumped it in and mixed it up very well. I think I can see black stuff in the bucket, The liquid went from a light green to a dark brownish color. but the SO2 smell is awful. I mean really pungent. Does that mean there was still Nitric acid in the mix? Will the smell go away with time? Does that mean I added to much SMB or not enough, or is it normal? I am a very smart guy but I really suck at this SIGH :*(

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Re: Help with Nitric Acid Elimination

Post by lazersteve » June 7th, 2010, 7:34 pm

That's nasty smell is normal. It's a choking odor that will make you cough and sneeze.

Nitrogen dioxides are red-brown and tend to smell similar to chlorine gas. Don't breath any of these as they are very bad for your health and can have delayed health effects.

The dark sediment is your gold.

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