# Aqua regia solution and trying to precipitate it.



## lets-fish (May 13, 2011)

Hello everyone I am new to all this and I have myself in a bind. I put about 4 LBS of gold plated pins(50's-60's era aerospace solding board style pins) and fingers from computers (which I removed from the boards prior to dropping in the aqua regia). I had roughly 7 gallons of solution made, which I diluted down to 2 -7 Gallons white buckets after the digestion process was complete(diluted with tap water). I added roughly 5 LBS of urea between the 2 buckets. I tested the solution and it has a PH of 2ish using PH test strips. The solution is green like a lime green when you look at the sides of the white bucket but as you look towards the center it gets darker almost a blackish. I figured if the plating is 10% of the the total weight (4lbs=64oz) that would be 6.4 ounces of actual gold, now if that 6.4oz gold is, lets say 10KT (40% pure) then I should have roughly 2 to 3 ounces. Please let me know if I am way off with my figures. I honestly think the plating was thicker though. When these pins were in the solution some of them would float to the top and still hold their shape and I could pull them out and melt them down and they would pass 14Kt acid test which means to me that the acid ate the core out. Anyways so far all I got out was 6.6 Grams of pure gold. I have used up 5 lbs of sodium metabisulfite. When I did the precipitant I used distilled water (8oz sodium metabisulfite to 16oz of water) and it was heated to close to boiling, so it was hot. When poured it in the buckets they would give fumes off similar to when I originally started the process. I don't have the shor gold testing liquid to see if there is any gold left in the buckets and I already have almost $100 dollars invested. I don't make that much due to I am active duty military and I really can't afford the $24 liquid tester if I am to only use a few drops. Is there any suggestion on how I can get anymore gold out or if that is all the gold I could get or if my calculations are incorrect. I thank you for reading this and hope I didn't screw anything up to bad.


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## qst42know (May 13, 2011)

Throw nothing away, not solid or solution. Cover your buckets but don't seal them tight. Make your own test solution, instructions can be found here on the forum, I wouldn't pay $24 a bottle either. Search for "stannous chloride".

A yield of 10% is unrealistic but 1-3 grams per pound of pins is.

Spend some time reading here on the forum, better processes exist for pins. When you find the threads that apply and you get stuck or need clarification just ask many here are willing to help.


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## Claudie (May 13, 2011)

If you have the gold in 14 gallons of solution, it may take some time to precipitate it all. Let it set and do some reading here. Make sure you have it stored in a safe place, somewhere that the fumes won't build up or be breathed in by someone.


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## Harold_V (May 14, 2011)

Your estimation of a few ounces is not reasonable. Pins don't yield even 1% gold. 
Precipitation of gold using SMB is an exothermic reaction. Heating the solution isn't in your best interest. It works perfectly well cold, and limits the amount of out-gassing you experience. 

Make some stannous chloride from a snippet of tin/silver solder (no lead solder), or buy some fishing weights made of tin. Use the resulting solution to determine if you have recovered all of the values from your two buckets of solution. If you don't understand what I'm taking about, read Hoke. She discusses testing and the making of the test solution. 

Harold


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## Claudie (May 14, 2011)

How to make & use Stannous Chloride http://goldrefiningforum.com/phpBB3/viewtopic.php?f=41&t=5271&p=45030#p45030 


Free copy of C. M. Hoke http://www.scribd.com/doc/2815953/Refining-Precious-Metal-Wastes-C1-M-Hoke


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## goldsilverpro (May 14, 2011)

lets-fish,

Where on earth did you come up with all those ridiculous numbers and all that erroneous information?


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## lets-fish (May 14, 2011)

Thank you for the post that actually have helpful information. To the posts that state useless info like where did you come up with ridiculous numbers and such, please read the original post in which I said, I am NEW to all this. I had no idea that the plating was so thin.


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## Anonymous (May 14, 2011)

lets-fish said:


> To the posts that state useless info like where did you come up with ridiculous numbers and such, please read the original post in which I said, I am NEW to all this. I had no idea that the plating was so thin.


I would highly suggest that you refrain from speaking(typing) to him in this manner.
His post was not useless,he wanted to know whether you read this somewhere,someone told you,or whether you came up with these figures on your own.And I would like you to answer the question.Did you read somewhere that these yields would be accurate?Or did you just assume those figures?


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## glondor (May 14, 2011)

From my limited experience everything said above is refining gospel. 

Save everything you currently have. 

Read a lot more on this site. 

Ignore any thing or information from Shor.

Do your home work on precious metal content of the many types of escrap.

Use your chemicals sparingly, I will not do the math, but 14 gallons of A/R Is enough to process many many many times the amount of gold you can expect. Maybe even kilo's of gold.

Sort your materials and do by type.

Remove base metals first. 

The learning curve is steep, but once you understand what you are looking at and dealing with you will get better results.

You will still make mistakes. I hope you will continue to learn and at least recover your current experiment. Dispose of your spent solutions properly. Cheers and happy learning.


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## goldsilverpro (May 14, 2011)

lets-fish said:


> Thank you for the post that actually have helpful information. To the posts that state useless info like where did you come up with ridiculous numbers and such, please read the original post in which I said, I am NEW to all this. I had no idea that the plating was so thin.



I'm sure I could have been more tactful but, at least, I think I got your attention. Newbie or not, you picked up a lot of bad info from somewhere. Glondor summed things up quite well but let me elaborate on a few things.

(1) I haven't actually run pins for about 20 years but I think the accepted value on the forum is about 1 to 3 g of gold per pound of pins - someone correct me if I'm wrong. There are exceptions, of course, but most stuff seems to fall within that range. You recovered 6.6 g from 4 pounds = 1.65 g/#. That figure does fall in the range and maybe that's all there is. However, the way you did things, with tons of solution containing a little gold, it is easy to leave a bit unprecipitated (or lost in the shuffle). Actually, I am pleasantly surprised you got 6.6 g, considering the way you did things. You'll never know what gold you're leaving behind unless you can test the solution with stannous chloride.

(2) The Shor site does have a lot of good information but it should only be examined in light of what you've learned on this forum. Shor is in the business of selling overpriced chemicals and equipment to the unlearned novice and, after you buy it, you're pretty much on your own. The Shor info is not wrong but it is very incomplete, oversimplified, and easy to misinterpret for the uninitiated. 

(3) Your biggest mistake was to dissolve everything in aqua regia. As you will learn on this forum, it is far, far better to first dissolve everything except the gold, using one of several different methods. That way, all of the remaining gold solids can easily be collected into a small pile and then dissolved in a small amount of an acid mixture and easily precipitated. Using this approach, it is much easier (and cheaper) to get it all the first time.

It's obvious that you are a smart guy and you did make a excellent attempt on your first batch. Your problem was the source of information you used. Now you've found the right place to start over and do things right. If you really want to learn this stuff, this forum is the only place on the internet where you'll find exactly how to do it and how to do it efficiently, safely, and inexpensively. However, as many have discovered before, this requires a lot of searching and reading and learning how to ask the right questions.

Welcome to the forum,

Chris


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## Oz (May 14, 2011)

glondor said:


> Use your chemicals sparingly, I will not do the math, but 14 gallons of A/R Is enough to process many many many times the amount of gold you can expect. Maybe even kilo's of gold.


I couldn’t help myself, I ran the numbers, but he had 7 gallons of AR made that he diluted to 14 gallons with water. So assuming a 4:1 ratio of HCl/HNO3 and discounting the 7 gallons of water, he had 26.49788 liters or 26,497.88 ml of AR. 

In this case there are a lot of base metals that are consuming acid, but that amount of AR can digest 1,076 Troy ounces of gold that is worth $1,608,835.20 at today’s spot price. Oh, that is 33.4673 kilos of fine gold.


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## glondor (May 14, 2011)

Oz. That truly is an eye opener. I knew that much A/R could put a lot of gold in solution but 33 and a half kilo's is astounding.

You could hide a LOT of gold in a 55 gallon drum in solution.


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## Anonymous (May 14, 2011)

glondor said:


> You could hide a LOT of gold in a 55 gallon drum in solution.


Ohhhh that gives me an idea! :mrgreen:


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## lets-fish (May 14, 2011)

Thank you Chris for the info. I wasn't trying to be a --- but the way you came across was kind of insulting since I am new to this and was looking for help. I didn't get those figures online, I came up with them myself, I have never done pins and such before so I didn't think that the plating was that thin. The pins aren't really pins that you might be thinking of, they are more like solder points, its is difficult to discribe. I guess the best way to discribe them is they look like a rook from a chess board. The only reason I though they might have a higher yield was when I put them in the solution after a while they would float to the top and I could pick them out with tweezers and they would hold their shape, then I would flatten them and run an acid test and they passed the 14K test. I just got another 3.7 grams out of the batch. So now I am really confused, I have been doing some more research here and your figures are pretty much on point. I guess I'll keep playing around with it and keep doing some research here. This site has a lot of knowledgeable folks here that are willing to help and people like me are extremely greatful for that help. If I come up with anything else on this batch I will keep you all posted. Thank you all again for your help and insight.


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## patnor1011 (May 14, 2011)

lets-fish said:


> The only reason I though they might have a higher yield was when I put them in the solution after a while they would float to the top and I could pick them out with tweezers and they would hold their shape, then I would flatten them and run an acid test and they passed the 14K test.



This would be because they were not completely dissolved from inside. There is not such a thing like 14k gold plating on electronics. IMHO


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## butcher (May 14, 2011)

with that much acid you should have everything dissolved, and an awful lot of nitric to evaporate off.


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## lets-fish (May 15, 2011)

Oz said:


> glondor said:
> 
> 
> > Use your chemicals sparingly, I will not do the math, but 14 gallons of A/R Is enough to process many many many times the amount of gold you can expect. Maybe even kilo's of gold.
> ...




Then in that case I made a industrial size of it LOL. I know now never to make so much next time I will make a small batch, I'm sure it will be easier to control too. Thank you for your post it was very informative. Too bad I didn't have that much gold to digest.


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## Claudie (May 15, 2011)

Don't throw it out. With 14 gallons of solution, it may take a week or longer for it to precipitate all the gold.


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## goldenchild (May 15, 2011)

lets-fish said:


> Oz said:
> 
> 
> > glondor said:
> ...


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## jwbrdkllr (May 19, 2011)

wow, that was a little excessive, but if the numbers are right that's 2.575 gm out of a # (10.3 per the 4#) I'd take that any day. That old stuff is always the best. And as one broke ass jarhead to another service guy( ain't you happy your gov't pays you what your worth) HAHAHA :mrgreen:


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