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recover gold and silver from sand

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john_paok

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Post September 19th, 2012, 5:32 am

recover gold and silver from sand

Hi all,

I try to recover gold and silver from sand. I upload pics from my material. I have melt the sand and it is 24.5 grams. First I done inquarting method I put 75grams of nitric acid. I have not see something in my material and I have try with aqua regia to recover some gold. I put 100grams of Hcl acid and 25grams of nitric acid. More I put SMB and one day later nothing. And the last, I put two copper pipe in hot place and the result is that, the first pipe was gone and the second you can see bellow.
can I recover some silver? this is silver cristals on second copper pipe?
the copper pipes in my material was stay 2 days outside (not in home temperature)
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john_paok

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Post September 20th, 2012, 12:40 am

Re: recover gold and silver from sand

May the title of this topic is not correct. I'd like to tell me someone if this material has silver. Also, how can I recover it?
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9kuuby9

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Post September 20th, 2012, 4:19 am

Re: recover gold and silver from sand

Hello,

Can you provide us with more information?

It seems like you have copper oxide, silver crystals and copper nitrate on your copper pipe that your are cementing with.
"Good judgment comes from experience, and a lot of that comes from bad judgment."
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bogarasjoe

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Post September 20th, 2012, 9:54 am

Re: recover gold and silver from sand

Did you test the AR solution with SnCl2?
Did you neutralize it?
If you precipitate with Cu, silver precipitates too.
I think SMB is much more selective.

Regards, Dave
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john_paok

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Post September 20th, 2012, 2:22 pm

Re: recover gold and silver from sand

I'll try this proccess from the begin. I'd like to refine silver and gold. I'm not sure how much gold and silver contain this material but I belive it has. So, first must I take the hematite and magnetite with strong magnets? then must I put nitric acid and distil water 1:1 ratio in 2.5 times more of material ? and then must I heat up about one hour on hot place ?

http://www.goldnscrap.com/index.php?option=com_content&view=article&id=67:refining-karat-gold-and-silver-jewelry-using-inquarting-method-part-1&catid=25:gold&Itemid=20
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butcher

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Post September 20th, 2012, 9:03 pm

Re: recover gold and silver from sand

I do not know if there is gold or silver in your material, an assay would tell you if it is worth going after, personally I would just pan the material for value’s and forget fooling with the black sands (too much trouble for too little value).

In the top picture all I can see are copper salts, in the lower picture the aqua regia solution with High volumes of nitric acid, is very green this can be from iron or copper, from this mix even if nitric was removed properly from solution, and there was possibly any value in solution (from the picture I doubt there is value in the solution. what did the stannous chloride test show? ), you most likely would not be able to precipitate gold with a chemical reagent (if by chance it had gold cement it with copper),

If you had values they are possibly left in the materials left from the acid treatments, as the metals like iron would dissolve into solution and push out any gold.

Aqua regia is a very poor choice for leaching ore, especially black sands which are mostly iron compounds very hard to break.
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bogarasjoe

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Post September 21st, 2012, 3:43 am

Re: recover gold and silver from sand

Sorry, I can't really understand your first step, the inquartation method. Did you melt the sand???
I think, inquartation is a refining method for carat gold only, not for sand / ore.
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galenrog

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Post September 21st, 2012, 10:41 pm

Re: recover gold and silver from sand

My suggestion would be to smelt the PM bearing sands. If you then have a gold button at the bottom of your conical mold, use standard refining methods found in this forum. I would also suggest you look at the many prospecting and small scale mining websites for advice on concentrating and smelting gold bearing sands.

If you simply want to find out if there is gold and roughly how much gold, then a assay is a must. Not all sands that are heavy with magnetics are gold bearing, but nearly all gold bearing sands are heavy with magnetics.
Mine gold. Buy silver. Fills the safe faster.
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john_paok

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Post September 22nd, 2012, 1:53 am

Re: recover gold and silver from sand

step by step...

first, I have sand 50 grams and put 200 grams of hcl acid slow. After , I had put nitric acid 50 grams 2,5 grams each time. this process had duration about 12 hours. now I upload pics from my solution.

what can I do if some sand have not dissolve? and when must I filtering? or refresh my solution?
I see my solution has precipitate, normally it mustn't has?
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bogarasjoe

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Post September 22nd, 2012, 3:07 am

Re: recover gold and silver from sand

Very interesting, guys!
The colour of your solution is much better :)!
Test ever with SNCl2! Gold refining without testing with SnCl2 is like hunting without cartridge.
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john_paok

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Post September 22nd, 2012, 5:17 am

Re: recover gold and silver from sand

the duration which I needed to put nitric acid in solution it was 6 hours. So, after 12 hours, now I heat slow my solution and I upload the results on this pics bellow.

But may it has small quantity black sand, what can I do to remove it? In the filtering must I'll take the solution or the precipitate?
I have not SNCl2 now. Can I put in my solution Sn or aluminium leafs?
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bogarasjoe

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Post September 22nd, 2012, 7:01 am

Re: recover gold and silver from sand

I think you should let it to settle for several days, than carefully pour of the solution and filter. Don't drop tin in to your solution! This way you will lose your gold, if there are any gold in you solution (if you add tin, gold will drop as colloidal gold, that you can not filtrate).
You should get some SnCl2, believe us! If you have any tin, add it to concentrated HCl, boil it gentle and let to dissolve. Leadless solder (with a minimum of 95% Sn) works well.
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john_paok

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Post September 22nd, 2012, 8:12 am

Re: recover gold and silver from sand

bogarasjoe wrote:I think you should let it to settle for several days, than carefully pour of the solution and filter. Don't drop tin in to your solution! This way you will lose your gold, if there are any gold in you solution (if you add tin, gold will drop as colloidal gold, that you can not filtrate).
You should get some SnCl2, believe us! If you have any tin, add it to concentrated HCl, boil it gentle and let to dissolve. Leadless solder (with a minimum of 95% Sn) works well.


thanks bogarasjoe,

Must I heat low this solution every day? if I check it with SnCl2 what can I'll see? only if it has a gold? and after filtering must I put HCl acid?
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bogarasjoe

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Post September 22nd, 2012, 3:53 pm

Re: recover gold and silver from sand

I mentioned that if you drop a piece of tin in a few ml of HCl, and heat it dissolves faster. Or heat just to begin fizzing, and let it for several days. Filtere, and here is the SnCl2 solution. Drop the test solution on a filter paper.
Drop your AR solution. If there are any gold, paper will get purple or black.
Use ever fresh test solution (ever 3 weeks).
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john_paok

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Post September 22nd, 2012, 4:04 pm

Re: recover gold and silver from sand

bogarasjoe wrote:I think you should let it to settle for several days, than carefully pour of the solution and filter. Don't drop tin in to your solution! This way you will lose your gold, if there are any gold in you solution (if you add tin, gold will drop as colloidal gold, that you can not filtrate).
You should get some SnCl2, believe us! If you have any tin, add it to concentrated HCl, boil it gentle and let to dissolve. Leadless solder (with a minimum of 95% Sn) works well.


Sorry bogarasjoe,

Now I understand what you tell me and this is that I wonder, if I boil Hcl acid with tin. Can I put aluminium leafs instead of tin? because it's better material which I have regarding purity and how many grams? I have HCl acid about 37%. If I boil 100ml of 37% HCl acid how many grams of alluminium must I put in HCl acid?

ever 3 weeks??? :) how many days must I stay my material in AR??? :x
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butcher

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Post September 22nd, 2012, 4:53 pm

Re: recover gold and silver from sand

Stannous chloride (tin chloride) a test for gold in solution, the stannous chloride testing solution is tin dissolved in an HCl solution, this chemical reagent makes a very sesitive test for gold in solution,

A drop of solution suspected to contain gold on a filter paper (Q-tip), or in a white spot plate, will turn a violet color when a drop of the stannous chloride is added if the solution contains gold).

other metals will not produce this reaction.

Too much oxidizer (nitric in aqua regia), or (chlorine in solution) will also keep this reaction from working, as the purple color comes from the stannous chloride reducing the gold in solution to metal colloids that do not settle but reflect light to give the violet color.

Too much SMB can produce a brown reaction (false positive).


Iron can give a yellow color to solution, that can look like the yellow solution we get from having gold in solution, if in doubt if the solution is gold or iron you can use the stannous test for gold and another test for iron.

Test for Iron II and Iron III Ions, In the identification tests for the Fe2+ and Fe3+ ions use ferrocyanide, (deep blue reaction).

Sodium or potassium or ammonium thiocyanate solution) to a solution containing iron(III) ions, you get a (blood red solution) if positive for iron.

Black sand is high in iron so I would tend to believe the yellow solution is iron until a test proved differently.
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bogarasjoe

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Post September 23rd, 2012, 3:08 am

Re: recover gold and silver from sand

Absolutely rigth, butcher! Very good tests for iron ions!
And why woluld you like to drop Al in to your vessel? Would you like to drop gold wit it? Use SMB! With aluminium, so much base metals would come with your gold (if present).
Don't worry, it is just a few day for AR to dissolve the materials at room temperature. With heating it can speed up for several hours.
But if you do something wrong, it can be several weeks, or several months / years, to get your first gold. It was 3 months for me, to get my first pure gold:). It is not easy... But it was my nicest chemical experiment ever.
Be ever safe, wear protection!
Reagards, Dave
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john_paok

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Post September 23rd, 2012, 9:11 am

Re: recover gold and silver from sand

Absolutely rigth, butcher! Very good tests for iron ions!


yes it has magnetite and iron maybe and hematite.
I hope AR dissolve gold with those metals in my solution

And why woluld you like to drop Al in to your vessel? Would you like to drop gold wit it? Use SMB! With aluminium, so much base metals would come with your gold (if present).


I had reed this article bellow,

http://webpages.charter.net/kwilliams00/bcftp/bcftp.htm
espassialy follow,

Aqua Regia
.
.
.
Aqua regia dissolves gold and all the platinum metals very rapidly (especially if hot). It will also dissolve damn near anything else in your sample. Silver, iron, magnesium, manganese, aluminum, etc. In fact it will attack any metal.

If you dissolve gold in aqua regia and want to recover it you will find that you must remove the nitric acid by evaporating the solution with heat. This will produce lots of the red vapor. You must not let the solution go completely dry. Stop heating when you still have just a little liquid left. Now you must add more hydrochloric and repeat the procedure. Repeat this evaporation 3 times or until there are no more red fumes coming off. Now add hydrochloric so that you have enough liquid to work with. All the metals will be in solution as their chloride salts. If you dilute this solution with an equal volume of water you will probably get a white cloud of silver chloride which you can filter off. Now to recover you’re gold. Probably the easiest is to cement it down by adding pieces of zinc or aluminum. You will get a black-brown precipitate in the bottom that you can smelt back to nice yellow gold. There are numerous other ways to recover the gold but that’s another page.


Tomorrow I buy SnCl2. It is faster than that if I was making :)
and one question more... :)
I'd like gold ions, how can I do that???? if I put gold leaf in equal amount nitric acid? or in AR?

Thank a lot all for your answer
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butcher

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Post September 23rd, 2012, 9:14 pm

Re: recover gold and silver from sand

Yes the aqua regia will dissolve darn near all metals but that does not mean they will stay in solution, there is a bug in that theory, called the reactivity series of metals, it says a more reactive metal will replace a less active metal from solution.

This is the same principle or theory that zinc will cement gold from solution (zinc is much more reactive than gold in the reactivity series of metals) google reactivity series of metals to learn more.

Platinum does not go into solution easy, sometimes it seems it will take forever.

You will have gold ions when you have gold in solution.

Aluminum can form a gel in solution (keep it out).
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bogarasjoe

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Post September 24th, 2012, 1:11 am

Re: recover gold and silver from sand

You will never dissolve platinum with AR at room temperature!
Yes, if you drop a piece of aluminium (and there is gold in your solution), gold will drop. But there are so much other base metals in your solution. If you drop Al in to it, it will reduce your gold and some of the base metals (Cu, Ag, Ni etc.) too. So your gold will be contaminated with other metals. Google reactivity series and standard potentials!
Regards, Dave
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