Advice for next step, failed recovery salts

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Bluebloomer

Bluebloomer

Well-known member
Joined
Jul 7, 2014
Messages
140
Location
Netherlands
Hello my fellow goldseekers.. Over the past year and a half, I messed around with acids but only achieved failed recoveries. Only thing recovered is an ounce of silver. I totaly did everything wrong overusing nitric acid big time. Learned a lot since and now trying to deal with the mess I left behind; around 1200 grams of various colored lumps and powders.
Most of it is an AR solutions that failed to precipiate anything, so I tried to salvage what I could by putting aluminum and or iron in the AR filter the precipitate and put it aside. Then I added sodium hydroxide to the solution and that produced another precipitate that looked like AgCl, but I think that's just from the reaction between an acid and a base. Not sure if it held any metals, so I even saved that, also used a lot of soda ash for neutralization and I think a lot of it is in the powders.

Now I would like your advice for a step by step approach in dealing with this mess. There is iron, aluminum, tin, and iron inside, also Nh3, Hno3, Hcl, NaOh and soda ash.
I am not sure about the amount of precious metals and it all might be a big waste of resources, but I have to try.

So, what would be the most logical step ? Dissolve it all in a solution with sodium hydroxide, and rinse it until PH becomes neutral ? Then dry it, incinerate and use nitrc acid as the first step to re-recover the precious metals ? I know there is gold inside, aswel as AgCl, metallic silver, and some palladium / platinum from around 100gr of MLCC's that failed horrible.

If I wash it first in sodium hydroxide, will it (partly) remove the bleach, ammonia, tin, aluminum and metastannic acid ?
I think the white precipitation of an acid and a base does not contain any metals but the salts from the acids breaking down, but they do take up a lot of volume of the 1200 grams of salts.

Tried to dissolve a small batch of the salts in 32% sulphuric acid but that produced a mountain of foam, therefore I think sodium hydroxide is the first step.
Any help would be greatly apreciated because I would like to fix this mess as it is a constant reminder of my stupidity last year.
 
Most of it is an AR solutions that failed to precipiate anything, so I tried to salvage what I could by putting aluminum and or iron in the AR filter the precipitate and put it aside
Click to expand...
Adding copper and filtering out solids would have saved you lot of headache. I would personally open Hoke and follow step by step "The Stock Pot".

What I'm sorry not to see be part of your plan is to use the eye of the refiner.

Marco
 
Adding copper and filtering out solids would have saved you lot of headache.
Click to expand...

Yes, I learned that after the fact.. I only read Hokes half way, and what I read, I apperntly misunderstood.

What I'm sorry not to see be part of your plan is to use the eye of the refiner.
Click to expand...

That sentence I do not understand
 
It appears you really have created a big mess but all is not lost.
First thing you have to do is read Hoke and then read again and again until it makes sense.
My advice for your recovered powders would be to first put into a beaker add water and boil this should remove most of the salts, do this several times and then filter the remaining powder. The next step would be incineration but only do this if you have decent extraction or do it outside, then place resulting powder into a beaker and slowly add HCl do this without heat and using extraction as the fumes will be extremely vigorous. Once the material has stopped reacting to additions of acid heat your beaker to ensure all the material that can be dissolved has been, then filter and test discarded acid for values, Pd is a possibility. This should have removed most of the base metals but not all so then use any of the accepted methods to dissolve the values and any other base metals, if you have silver in the mix it will remain as chloride that can be recovered off the filter paper.
The chances are that your solution and resulting gold will be rather dirty so after precipitation and rinsing I'd suggest another refining cycle to purify your powder.
If any of the above advice makes no sense keep reading and only attempt to recover your values when you have a full understanding of the processes involved including the risks.
 
Hi nickvc,

It makes perfect sense. And yes I made a real stupid mess, mainly due to the overuse of nitric acid. That brought me in a lot of trouble..
I also forgot to mention there is like 10 grams of gold from a failed oxalic acid refining, leaving me with a beaker full of goo but no more gold. I think I overdid the lowering of the PH.

Boiling the salts in a beaker is a bit diffucult as it takes up nearly 3 litres of volume. So that would mean like 20-30 batches to boil..

But I will try a small batch to see how that works out.. Thank you for your input.
I used to just figure it out on the fly, but that didn't work out so well for me..
 
@MarcoP: once I start leeching I will use stannous chloride for sure, but what good would that do me now ? Took me a moment to realize what you ment.

Washing the solids went better than expected.

- Added boiling water to a third of the powders and kept stirring it.
- PH shot up to 12-14 so there was a lot of soda ash / sodium hydroxide still in there.
- Let the solution settle and siphon it
- I repeat this process 4-5 times per batch untill PH was 7-8

Volume has been reduced by a third, at least.
The remaining powders are dried in a frying pan.
It's all powders and small lumps with a brownish / red color (iron oxide and or copper ? )

So the powders are washed and dried, volume reduced by a third, weight has been reduced by a third and the powders are uniform in size.
Now they will be incinerated and then the next step; either leeching in nitric acid or hcl.

If I was to leech in HCL it could remove most of the iron, copper, and tin, reducing the volume even more but it might give me a lot of silver chloride.
If I was to leech in nitric acid I could remove the silver in one step but then the tin might cause a lot of metastannic acid.

So HCL seems to be the most logical step.
 
Yeap, was a tricky thing from me...

Bluebloomer, I'm worried if your gold, or some of it, is now in the liquid you siphoned out. Stannous Chloride can tell you, anytime, if your gold is in solution. I'm don't if the Stannous also worth in basic solutions, I would try on a sample and if negative I would acidify the sample and try again.

Last time I did a small test batch, before I even started I made some fresh Stannous because I've luckily understood the importance of such simple tool.

Bluemooner said:
I tried to salvage what I could by putting aluminum and or iron in the AR filter the precipitate and put it aside.
Click to expand...
I got lost, English is not my mother language. Where is the powder you put aside. Were your PH adjustments done in a solution made from the above precipitate or was it done in the solution leftover after the cementation.

Marco
 
I now know I made 2 big mistakes; using too much nitric acid, and impatience; not waiting long enough for the AR to precipitate after a few days or so.

So when the AR did not precipitate the gold, I added copper, iron or aluminum, and then let it stand for a day or so.

The precipitate was filterted and added to the stockpot, the AR was neutralized was a NaOh wattery solution.
This gave a reaction like silver chloride, a fluffy precipitate filled the flask. So I filterted this precipitate with a cloth thinking it would still hold any PM.
Now I know that the precipitate was nothing more than the breakdown of the acids and the caustic solution.

So when I added boiling water to the salts and powders and the PH raised to 12-14 I was under the impression that only the amphoteric metals like aluminum and zinc could dissolve and be washed away.
I did not think testing with stannous chloride would mean anything at this stage becasue of the high PH. I though only acidic solutions could be tested.

Gold cannot dissolve in a solution with sodium hydroxide, but you can use sodium hydroxide to precipiate gold. At least that is what I read.
I used a small aquarium airhose tied to a steel rod to siphon the liquid off, after it settled for like 20 minutes.
 
All your values and your silver chloride are in your stock pot now. The rest is a solution to treat as a waste, no values to chase.
 
Your going the right way to recover your values and it seems your learning along the way which is even better.
The reason I suggested incineration and then HCl was to remove the tin which is a nightmare to filter but it can and will dissolve other base metals along with possibly Pd which is why I suggested testing the resultant solution. Yes you might end up with silver chloride but in small quantities it's easy to convert back to metal using the processes outlined here on the forum.
I could give full details and processes but I feel the OP will learn and benefit more if I leave some of the decisions to him, so keep reading and advise us of your next proposed step before starting, if it's wrong someone will step in and tell you.
 
Bluebloomer said:
Now I know that the precipitate was nothing more than the breakdown of the acids and the caustic solution.
Click to expand...
The mixture of your acids (HCl and HNO3 in this case) and NaOH would not break down, it would form sodium chloride or sodium nitrate and wouldn't form any precipitates as it is highly soluble. What you got was other metals in solution that formed hydroxides that isn't soluble.

By the way, it's NaOH, not NaOh. See the difference?

Göran
 
All your values and your silver chloride are in your stock pot now. The rest is a solution to treat as a waste, no values to chase.
Click to expand...

Mission partly accomplished. Now I lower PH to neutral, filter remaining hydroxides and discard.

@nickvc: My arrogance has dropped.. ;) I think I was being arrogant to think I could read just a little and do the rest on the fly. When powders are dry I will roast them until glowing red, and then I will leech it first in HCL so base metals can be removed. After that volume of the powders will be reduced even more making recovery a lot easier as it is a relative clean material now.
I will post all my following steps before I take them because this I want to do it absolutely right because I have wasted far too much acids and recources already.

@Goran: thank you for the clarrification; and I will not forget the H anymore..
 
It isn't arrogance if you try to learn after trying what seems so simple from the Utube videos that show only part of the whole process. Yes you messed up but you had the sense to stop read and think, this mess you made is one very good learning experience that will help you greatly in the future 8)
 
Hi.
The best and most profitable thing you can do right now is to slowly evaporate any and all solutions and collect "ALL" solids for storage.

Like everyone, you dove in without learning.

You now have solutions and solids and now your gold is hiding from you because you did not learn how to follow it.

It's still hiding there as long as you did not throw anything away.

Store and learn how to find your gold now as I can not follow what you did and what every one here is trying to help you with...Aside from testing.

Good luck and learn patience most of all...

B.S.
 

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