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will ferrous sulphate drop the gold???

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batesy53

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Post April 25th, 2012, 4:45 pm

will ferrous sulphate drop the gold???

hey there

i am dissolving some cpus in 1 oz batches at the moment until i get this right.i am dissolving in AR 1-4 ratio,filtering a couple times,then adding urea an abit of warm water to the mixture..everything swt up2 adding the precipitant...i was told to use ferrous sulphate to precipitate the gold??will this work???how much do i add to a 1oz batch??how long will it take??do i need 2 dissolve it in warm water 1st??

any clues r greatly appreciated
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NobleMetalWorks

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Post April 25th, 2012, 5:50 pm

Re: will ferrous sulphate drop the gold???

Ferrous Sulphate will drop out everything in solution that is lower on the reactivity series, than Iron, ferrous sulphate is really iron. As gold is lower on the reactivity series table, it will precipitate out Au, but also everything else under Fe. Should you use it to precipitate Au? It really depends on what you have in solution, what you want to get out of solution, and what point in your process you are.

For reference look here for the reactivity series:

http://www.zephyrus.co.uk/thereactivityseries.html

There are many other people that know far more about this than I do, if one of you would like to fill in the rest of what I might missed so I can learn also, I would appreciate it. Or if I have posted anything incorrect, please correct me.

Thanks

Scott
At the heart of science is an essential balance between two seemingly contradictory attitudes--an openness to new ideas, no matter how bizarre or counterintuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense. -- Carl Sagan

"When I get a little money I buy books; and if any is left I buy food and clothes". Erasmus (1467-1536))
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Geo

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Post April 25th, 2012, 7:17 pm

Re: will ferrous sulphate drop the gold???

ferrous sulfate is copperas.it is used to precipitate gold. many members use it to process their gold.
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butcher

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Post April 25th, 2012, 8:42 pm

Re: will ferrous sulphate drop the gold???

Copperas or ferrous sulfate is a very good gold precipitant, in fact many times I prefer Copperas for precipitating gold instead of using sodium metabisulfate.

(Edit: I goofed the chemical I meant to say was sodium metabisulfite). :oops:

Hokes book also uses copperas to precipitate gold, she even explains how to test for gold in solution using ferrous sulfate.

I have not noticed any more base metals precipitating when using FeSO4 than I have from using SMB. In fact I would guess that SMB in excess would be more likely to precipitate copper than ferrous sulfate in excess would, especially if your gold solution was contaminated with copper.

Ferrous sulfate is a salt of iron (iron and sulfuric acid), but it does not act the same in a copper solution as the elemental metal Iron would react to precipitate the copper, the iron metal bar has all of its electrons to share and will give these electrons up to the copper in solution, so copper ions would convert to metal copper powder, the ferrous sulfate does not have excess electrons to share and so it does not precipitate the copper, so here copper and iron can be in solution together as ions.
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NobleMetalWorks

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Post April 25th, 2012, 8:50 pm

Re: will ferrous sulphate drop the gold???

butcher wrote:Copperas or ferrous sulfate is a very good gold precipitant, in fact many times I prefer Copperas for precipitating gold instead of using sodium metabisulfate.

Hokes book also uses copperas to precipitate gold, she even explains how to test for gold in solution using ferrous sulfate.

I have not noticed any more base metals precipitating when using FeSO4 than I have from using SMB. In fact I would guess that SMB in excess would be more likely to precipitate copper than ferrous sulfate in excess would, especially if your gold solution was contaminated with copper.

Ferrous sulfate is a salt of iron (iron and sulfuric acid), but it does not act the same in a copper solution as the elemental metal Iron would react to precipitate the copper, the iron metal bar has all of its electrons to share and will give these electrons up to the copper in solution, so copper ions would convert to metal copper powder, the ferrous sulfate does not have excess electrons to share and so it does not precipitate the copper, so here copper and iron can be in solution together as ions.


Butcher,

Thank you for the correction and explanation.

Scott
At the heart of science is an essential balance between two seemingly contradictory attitudes--an openness to new ideas, no matter how bizarre or counterintuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense. -- Carl Sagan

"When I get a little money I buy books; and if any is left I buy food and clothes". Erasmus (1467-1536))
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butcher

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Post April 25th, 2012, 9:33 pm

Re: will ferrous sulphate drop the gold???

Scott,
You are correct that it is the iron in the copperas that precipitates the gold, here is something else to consider, if you have gold and platinum in solution, ferrous sulfate will precipitate the gold but not the platinum (platinum is below iron in the reactivity series), if we added a bar of elemental iron to the solution of gold and platinum, the iron would give up electrons to both gold and platinum and precipitate both of these metals from solution.

The reactions of the metal and ferrous sulfate in these examples are different types of reactions.
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NobleMetalWorks

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Post April 25th, 2012, 10:45 pm

Re: will ferrous sulphate drop the gold???

After I read what was posted, after my post, I referred to my chemistry book, I wanted to understand the differences exactly. I really appreciate the clarification.

Thank you

Scott
At the heart of science is an essential balance between two seemingly contradictory attitudes--an openness to new ideas, no matter how bizarre or counterintuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense. -- Carl Sagan

"When I get a little money I buy books; and if any is left I buy food and clothes". Erasmus (1467-1536))
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batesy53

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Post April 26th, 2012, 3:42 am

Re: will ferrous sulphate drop the gold???

thank you 4 your posts at least i am on the right track now..is it better to heat the solution slightly after i hav added the ferrous sulphate???thanks again 4 the help
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Harold_V

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Post April 26th, 2012, 4:04 am

Re: will ferrous sulphate drop the gold???

Heating is not a requirement, and, at least in some cases, can work against you. That is the case when precipitating with SO2 from concentrated solutions.

However, there are instances where heat is required, such as using oxalic acid.

Read Hoke.

Harold
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batesy53

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Post April 26th, 2012, 7:42 am

Re: will ferrous sulphate drop the gold???

thanks harold,so do i just leave it 2 do its thing for a little while???

thx
chris
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tek4g63

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Post April 26th, 2012, 8:19 am

Re: will ferrous sulphate drop the gold???

Butcher,
I hate to be this guy.

Copperas or ferrous sulfate is a very good gold precipitant, in fact many times I prefer Copperas for precipitating gold instead of using sodium metabisulfate


You ment sodium metabisulfite, correct?

Just want to keep it accurate for new members. Please don't hate me.
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maynman1751

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Post April 26th, 2012, 10:00 am

Re: will ferrous sulphate drop the gold???

tek4g63 wrote:Butcher,
I hate to be this guy.

Copperas or ferrous sulfate is a very good gold precipitant, in fact many times I prefer Copperas for precipitating gold instead of using sodium metabisulfate


You ment sodium metabisulfite, correct?

Just want to keep it accurate for new members. Please don't hate me.


Yes sir! You be right. You caught Butcher with a typo! It is indeed Sodium Metabisulf(ite) and NOT
Metabisulf(ate!)
You can't fix stupid...stupid is forever!

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philddreamer

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Post April 26th, 2012, 10:07 am

Re: will ferrous sulphate drop the gold???

It was probably an echo from repeating "iron sulphate".

Now, I have a question. Should we then use iron sulphate for precipitating the gold out of dirty solutions, instead of SMB?
Use SMB on "cleaner solutions"?

Phil
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You may say that I'm a dreamer... but I'm not the only one!
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maynman1751

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Post April 26th, 2012, 11:59 am

Re: will ferrous sulphate drop the gold???

philddreamer wrote:It was probably an echo from repeating "iron sulphate".


Now, I have a question. Should we then use iron sulphate for precipitating the gold out of dirty solutions, instead of SMB?
Use SMB on "cleaner solutions"?

Phil


I would imagine so. It's not often that that man is mistaken! 8)


I don't see that it would make a difference....or I don't get your logic!
You can't fix stupid...stupid is forever!

1.Forum Guide (Table of Contents) http://goldrefiningforum.com/phpBB3/viewtopic.php?f=60&t=5604
2.Guided tour viewtopic.php?p=6873#6873
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4.Get the (FREE) Gold Refining Forum Handbook VOL 1 here >> http://tinyurl.com/nyutnp
5.Get the (FREE) Gold Refining Forum Handbook VOL 2 (Final) here >> http://tinyurl.com/y9w5y73
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butcher

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Post April 26th, 2012, 12:34 pm

Re: will ferrous sulphate drop the gold???

You are very correct, I did make a mistake in my use of words, I meant to say sodium metabisulfite, (and not sodium metabisulfate), the endings in these chemical names are important as they contain differing amounts of oxygen and so they can react differently in solution.

Thank you for catching my goof, this also shows me your paying close attention and learning, and if I were allowed to use the wrong name for a chemical, some new member could think that it would work, or that we use that chemical when we do not, and not know I used the wrong name for that chemical, with chemistry and mixing chemicals and metals, using the wrong chemicals or chemical name, could become dangerous, I will post a correction to the post above in red.

Phil,

I think dirty solutions can be hard to precipitate from, no matter what chemical used, take the case of tin in solution for example tin is involved in electronics from the solder, when in a solution dissolved with gold, tin will reduce the gold, forming colloids in solution, these gold metal particles will not settle but become charged particles, and repel each other they will not combine, to precipitate, but keep each other in solution, they also have been reduced to metal gold particles (by the reaction with tin), so they have already have gained back their missing electrons, so adding a copper buss bar will not cement them or reduce them to metals (they are already reduced), these gold particles are already reduced to metal so stannous chloride will not test for gold in this solution, they are already gold metal particles so a chemicals will not reduce them, so we are stuck here, we cannot tell there is gold in this solution and we cannot precipitate the gold unless we can break the colloid, (high heat and raising acid content can help some here).
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Geo

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Post April 26th, 2012, 12:42 pm

Re: will ferrous sulphate drop the gold???

butcher wrote:You are very correct, I did make a mistake in my use of words, I meant to say sodium metabisulfite, (and not sodium metabisulfate), the endings in these chemical names are important as they contain differing amounts of oxygen and so they can react differently in solution.

Thank you for catching my goof, this also shows me your paying close attention and learning, and if I were allowed to use the wrong name for a chemical, some new member could think that it would work, or that we use that chemical when we do not, and not know I used the wrong name for that chemical, with chemistry and mixing chemicals and metals, using the wrong chemicals or chemical name, could become dangerous, I will post a correction to the post above in red.

Phil,

I think dirty solutions can be hard to precipitate from, no matter what chemical used, take the case of tin in solution for example tin is involved in electronics from the solder, when in a solution dissolved with gold, tin will reduce the gold, forming colloids in solution, these gold metal particles will not settle but become charged particles, and repel each other they will not combine, to precipitate, but keep each other in solution, they also have been reduced to metal gold particles (by the reaction with tin), so they have already have gained back their missing electrons, so adding a copper buss bar will not cement them or reduce them to metals (they are already reduced), these gold particles are already reduced to metal so stannous chloride will not test for gold in this solution, they are already gold metal particles so a chemicals will not reduce them, so we are stuck here, we cannot tell there is gold in this solution and we cannot precipitate the gold unless we can break the colloid, (high heat and raising acid content can help some here).


also keep in mind that these solutions will have a distinctive color, ranging from mauve to royal blue and even red.
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philddreamer

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Post April 26th, 2012, 1:02 pm

Re: will ferrous sulphate drop the gold???

Butcher wrote:
I have not noticed any more base metals precipitating when using FeSO4 than I have from using SMB. In fact I would guess that SMB in excess would be more likely to precipitate copper than ferrous sulfate in excess would, especially if your gold solution was contaminated with copper.


The material that I process has little tin, & most of the base metals are removed when I run the material either thru HCl or nitric in order to get rid of most of the base metals. So, copper & a bit of silver are usually the contaminants present in my AR. That's why I asked if precipitating my first round of AR with iron sulphate would give a "cleaner" gold; so, then I run the gold thru AR a second time, then precipitate with SMB. It was just a thought.

Thanks!

Phil
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WARNING: No "cartridge type" respirator will filter out nitric fumes, NONE!!!
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Harold_V

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Post April 26th, 2012, 1:12 pm

Re: will ferrous sulphate drop the gold???

batesy53 wrote:thanks harold,so do i just leave it 2 do its thing for a little while???

thx
chris

The reaction, assuming you have eliminated nitric completely, is immediate. No wait time is required, and the change is visibly obvious in that the solution clouds immediately, and changes color because the gold is removed as a solution. The cloudiness that appears is the fine particles of gold that precipitate.

We're a bit touchy (at least I am) on the use of trick substitutes of numbers for words. You will be well served to stop using the number 2 when you mean *to* or *too*. I get down-right unreasonable when folks do that. Here, where the use of wrong terms can spell the difference between success and failure---or danger and safety, we try to be very precise in what we say, and how it is said. None of us are perfect, but we do our best by eliminating contractions that may not be clear to some folks, in particular those who do not use English as a first language.

Harold
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butcher

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Post April 26th, 2012, 8:26 pm

Re: will ferrous sulphate drop the gold???

Philddreamer,
Hoke’s book speaks of refining the second time using a different precipitant than you used the first time, she says it helps, I believe these may act slightly different on which metals may also precipitate slightly from the solutions, but I am not real sure of details?
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philddreamer

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Post April 26th, 2012, 8:50 pm

Re: will ferrous sulphate drop the gold???

Thanks Richard!
I remembered reading so, & that's why I asked. Maybe the iron sulphate first & on the second SMB. I'm going to give a shot on my next batch.

Phil
If you are going to dream... DREAM BIG!!!
You may say that I'm a dreamer... but I'm not the only one!
"Paper money eventually returns to its intrinsic value --- zero." Voltaire (1694-1778)
The difference between a dream & reality is, a good plan!
WARNING: No "cartridge type" respirator will filter out nitric fumes, NONE!!!
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