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bleach, vinegar and salt dissolve gold

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Traveller11

Active Member

Posts: 281

Joined: December 24th, 2007, 2:14 am

Location: Sandspit, Queen Charlotte Islands, BC, Canada

Post September 8th, 2013, 9:40 pm

bleach, vinegar and salt dissolve gold

Subject: Re: Au Reaction
From: nreitzel@lonestar.jpl.utsa.edu (Norman L. Reitzel)
Date: Apr 16 1995
Newsgroups: sci.chem

In article <1995Apr16.104647.1@beach.utmb.edu> arussell@beach.utmb.edu writes:

> Still looking for someone who can fill in this reaction for me :
>
>NaClO + CH3COOH + AU ->
>then the reaction for bubbling SO2 through the solution to precipitate the Au
>out.

This is kind of a strange reaction, and it will go much quicker if you
add a source of chloride ions to the solution. Commercial bleach usually
contains sodium chloride and hypochlorite both. Without chloride ions,
the reaction takes an unusual pathway:

8NaClO + 2Au + 6HC2H3O2 --> 2NaAuCl4 + 6NaC2H3O2 + 3H2O + O2

If you have available free chloride ion, then the reaction takes a more
mundane course, and is much faster since ClO- doesn't have to oxidize
water to free oxygen:

6NaClO + 2NaCl + 2Au + 6HC2H3O2 --> 2NaAuCl4 + 6NaC2H3O2 + 3H2O

By bubbling sulfur dioxide through the solution, the chloroaurate is
reduced back to metallic gold while the sulfur dioxide is oxidized to a
plethora of sulfur species including dithionate, S2O6--. The overall
reaction is:

6SO2 + 6H2O + 12NaC2H3O2 + 2NaAuCl4 --> 12HC2H3O2 + 3Na2S2O6 + 8NaCl

In reality, there will be a half-dozen different sulfur species present,
everything from sulfite to sulfate and all the poly species in the middle.

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--------------------------------------------------------------------------------
Subject: Re: Au Reaction
From: reitzel@lonestar.jpl.utsa.edu (Norman L. Reitzel)
Date: Apr 16 1995
Newsgroups: sci.chem

In article <3mrqfu$4lb@ringer.cs.utsa.edu> nreitzel@lonestar.jpl.utsa.edu (Norman L. Reitzel ) writes:

>By bubbling sulfur dioxide through the solution, the chloroaurate is
>reduced back to metallic gold while the sulfur dioxide is oxidized to a
>plethora of sulfur species including dithionate, S2O6--. The overall
>reaction is:

> 6SO2 + 6H2O + 12NaC2H3O2 + 2NaAuCl4 --> 12HC2H3O2 + 3Na2S2O6 + 8NaCl

Uh, <acute embarassment>, that reaction should also include the
precipitated metallic gold:

6SO2 + 6H2O + 12NaC2H3O2 + 2NaAuCl4 -->
12HC2H3O2 + 3Na2S2O6 + 8NaCl + 2Au

Oh well. Typical chemical consultant. Run the reaction and keep the
gold for himself. Apologies.

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Note: The chemical formula CH3COOH is acetic acid or vinegar. The formula HC2H3O2 is the condensed formula for acetic acid, whose systematic name is ethanoic acid. The chemical process given above is not all it takes to make this work. The author has either left these steps out, or is unaware of what else needs to be done to make this work. For example, adding any volume of an acid to sodium hypochlorite bleach (NaClO), whose pH is well over 12, will, by virtue of the lowered pH, convert the hypochlorite to hypochlorous acid (HOCl).
"He was always cold, but the land of gold seemed to hold him like a spell....Though he'd often say, in his homely way, that he'd "sooner live in Hell"....." ~~Robert W. Service~~

"When you live beside the graveyard, you can't cry for every funeral." - Russian Proverb

"Good judgement comes from experience, and a lot of that comes from bad judgement." ~~Will Rogers~~
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Traveller11

Active Member

Posts: 281

Joined: December 24th, 2007, 2:14 am

Location: Sandspit, Queen Charlotte Islands, BC, Canada

Post March 26th, 2014, 12:02 am

Re: bleach, vinegar and salt dissolve gold

Went right over your heads again, did I?
"He was always cold, but the land of gold seemed to hold him like a spell....Though he'd often say, in his homely way, that he'd "sooner live in Hell"....." ~~Robert W. Service~~

"When you live beside the graveyard, you can't cry for every funeral." - Russian Proverb

"Good judgement comes from experience, and a lot of that comes from bad judgement." ~~Will Rogers~~
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nickvc

Active Member

Posts: 2614

Joined: September 14th, 2009, 9:53 am

Location: birmingham

Post March 26th, 2014, 4:48 am

Re: bleach, vinegar and salt dissolve gold

Traveller I'm no chemist so I can't answer your questions or fill in the missing reactions but I applaud your dedication to this subject. Perhaps you will just have to trial this method in a hood with decent extraction to find out if it works and how well, I'm fairly sure that every batch will need different tweaks to allow it to work to its best efficiency and that I guess is down to you to find.
If you can crack this I'm sure if you share you will have the thanks of all those miners trying to find easy and economic ways to treat their material, as usual it may well have uses in the general field of gold recovery if people can see it.
Good luck.
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rickbb

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Posts: 473

Joined: April 4th, 2013, 7:59 pm

Location: Central NC

Post March 26th, 2014, 1:02 pm

Re: bleach, vinegar and salt dissolve gold

Traveller11 wrote:Went right over your heads again, did I?


Yes, actually it did. :oops:
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FrugalRefiner

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Posts: 1169

Joined: January 14th, 2012, 5:06 pm

Location: Ohio, USA

Post March 26th, 2014, 3:24 pm

Re: bleach, vinegar and salt dissolve gold

Traveller11 wrote:Went right over your heads again, did I?

Was there a question?

Dave
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