will ferrous sulphate drop the gold???

[kjavanb123]

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,


hank you for the correction and explanation.

Scott

All,

As far as the copperas precitpiating only gold and not copper from a Au/Cu solution, I have to disagree, since I had a solution from AP process for fingers, and percipitated using copperas and the it produced gray/black powder instead of expected brown powder, after ammonia addition and boil, it turned dark brown color, so some other metals must have co-precipitated with gold.

Regards
Kevin

 

[butcher]

I was not trying to say that no copper would precipitate from using ferrous sulfate when precipitating gold from a dirty solution loaded with gold.

I was trying to explain that I believe less copper would precipitate from the same solution if copperous was used as opposed to SMB.

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.

I never said "copperas precitpiating only gold and not copper from a Au/Cu solution" as you assumed I was saying, when precipitating gold from dirty solutions you will get that dirt in your precipitatant, in this case precipitating gold from a solution loaded with copper you will precipitate copper with your gold, which ever of these reagents you use.

I was also not discussing using ferrous sulfate as a recovery method by using it to precipitate gold from a solution heavily contaminated with copper as with precipitating gold from a copper solution, I was discussing using ferrous sulfate to precipitate gold from a gold solution with minor copper contaminate in the gold chloride solution as in the refining process as opposed to the recovery process.

 

[badran106]

i saw that butcher is giving us information...i will read it later ....thank you man you are kind..

 

[butcher]

badran106,

Basically garbage in your gold solution you get garbage out.
Keep the garbage out of your gold solutions.
That way you can precipitate a more pure gold from solution.
:lol:

 

[Anonymous]

To back up Butcher on his post. Excess SMB at outset appears to makes the dropping of any copper in solution with the gold very much more likely.

We've tried using large quantities of SMB to take the Chlorine out of a solution without boiling it off, and it has usually (over 70% of the time) resulted in a "dirty drop," pulling down any copper left, with the gold.

I have no experience with Ferrous Sulphate so I cannot comment on that part.

Jon

 

[steyr223]

Hey guys
I have used in excess of 30 to 100 time
Smb for probely my first 25 drops
Just for the record my gold has always been 98+%
So what do you consider excess smb
and what do you consider the amount of copper the extra
smb is dragging down.

One of my very first drops was from
A/R and I remember putting in so much smb( way over
used nitric) about a 1/2 of a container of smb but my gold dropped :mrgreen:

Thanks steyr223 rob

 

[butcher]

Why??

 

[bswartzwelder]

Hey guys
I have used in excess of 30 to 100 time
Smb for probely my first 25 drops
Just for the record my gold has always been 98+%
So what do you consider excess smb
and what do you consider the amount of copper the extra
smb is dragging down.

One of my very first drops was from
A/R and I remember putting in so much smb( way over
used nitric) about a 1/2 of a container of smb but my gold dropped :mrgreen:

Thanks steyr223 rob

I am pretty certain it takes about 1.1 ounces of SMB to precipitate 1 ounce of gold from your solution. By dumping in excess amounts of any chemical, you are creating more waste which at some time will need to be dealt with. Just my humble $0,02 worth.

 

[rickbb]

Perhaps your gold would have been 99.7%+ instead of 98%+ if you had only used the minimum amount of SMB?

 

[steyr223]

Perhaps your gold would have been 99.7%+ instead of 98%+ if you had only used the minimum amount of SMB?

Yes yes but of course that's funny you
mention 99.7%+ because that's exactly
what I get now :lol:

I guess thats my answer

Butcher my friend
What can I say I'm a stubborn learner
it only took 9 HNO3/HCl reactions for me
To stop my use of excessive nitric acid.
That's after reading it from the first time

Thanks steyr223 rob

 

[Richard NL]

Dear butcher, the man that makes me have multiple Mozilla's open, with many tabs.
Because you make many good posts, all over the forum.
I usually check, check and an independent check.

Keep up the good work.

But:

(platinum is below iron in the reactivity series)

is correct, but i think you meant gold in this instance.

In the reactivity series of metals (in aqueous solution), it is not always clear witch metal is above or below with gold and platinum (and sometimes lead).
http://tinyurl.com/levw387
http://tinyurl.com/lqwa72z

A search on G.R.F, only a short message: that the two are so close together, it doesn't matter.

Please correct me if I'm wrong or made a mistake, i am still learning.
Best regards Richard.

 

[butcher]

Richard NL,
Both gold and platinum are noble metals and both are much less reactive than Iron.
Platinum is much more less reactive than gold.


I often make some mistakes in what I say, so it is possible I said platinum when I meant to say gold, I am not sure where I made the mistake if I did, but if you point it out I will try to correct it.

 

[butcher]

The only place I see where I mention platinum in this topic, I believe I used it correctly.

If we have platinum and gold in solution and we use copperas (iron sulfate) (ferrous sulfate).We can precipitate the gold leaving platinum in solution, the Iron sulfate will not precipitate the platinum, but will precipitate gold.
Gold and platinum are both below iron in the reactivity series.
Even though platinum is below iron and gold in the reactivity series.


Iron metal if added to a solution of gold and platinum in solution would cement both gold and platinum from solution.

These are two different types of reactions, in the latter (cementing out metals with a metal of iron), the metal Iron gives electrons to the platinum ions (and the gold ions, or any ion less reactive than the iron metal in the reactivity series of metals) as the Iron goes into solution as an ion.

The copperas (ferrous sulfate) is an ionic salt of Iron and does not react the same as the iron metal does in the chemical reaction (cementing with a metal), the copperas reacts with the gold chloride to form iron chloride, as it takes the place of gold in solution and reduces the gold to metal.
in the copperas reaction the Iron ion (cation) replaces the gold ion (cation) in solution.

With iron metal (cementing out the metals) it is electrons given up by the iron metal to both gold and platinum converting the ions (cations) of these metals to atoms of these metals with a full shell of electrons.Again these metals (Gold, platinum,copper...) are reduced to metals as the iron metal is oxidized to cations.

With copperas we would not reduce many of the metals below iron in the reactivity series, but will leave these in solution with platinum as we reduce the gold in solution to metal using the iron sulfate (copperas) (ferrous sulfate).

With a bar of iron metal we would reduce any metal below iron out of solution with the gold and platinum.

 

[Richard NL]

Dear butcher, first off all i want to apology for not making myself clear enough.

Scott,
You are correct that it is the iron in the copperas that precipitates the gold, here is something else to consider,

new section

if you have gold and platinum in solution, ferrous sulfate

(not metallic element Iron)

will precipitate the gold but not the platinum (platinum is below ([stt]iron[/stt]) gold in the reactivity series),

next section

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.

I think that you are busy with the next sentence involving iron.
Every sentence on his one is correct, but if you look carefully to the complete story.

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).

Ferrous sulfate is not elemental iron.

Please correct me if I'm wrong or made a mistake, i am still learning.
Best regards, and merry Christmas, Richard.

 

[butcher]

I am getting lost.

Iron sulfate (copperas, or ferrous sulfate, FeSO4) will precipitate gold.
2AuCl3 (aq) + 6FeSO4 (aq) --> 2Au (s) + 2Fe2(SO4)3 +2FeCl3
Here we get elemental gold as the iron sulfate (iron cation) exchanges places with the gold cation.
The Chloride anion giving up the gold ion (the gold becomes a metal solid), and taking the iron cation in the place of the gold ion, the gold ion is reduced to become a metal, the ferrous (iron ion) stays in solution as a newly formed chloride ion.

Ferrous sulfate (iron sulfate) is not elemental iron, (although it is iron in solution as a cation), and in this reaction will not precipitate platinum from solution.
Platinum would stay an ion in solution it will not give up its bonds with chloride as easily as the gold did (or with copperas) it is happy happy to stay in solution.

----------------------------------------------------------------------------------------
Cementing with iron metal.
With Iron metal we use the reactivity series of the metal to cement gold and platinum from solution, or any metal below iron in the reactivity series that happens to be in solution, iron donates electrons, to these metals in solution (below iron in the reactivity series), these metal Ions gaining these electrons from the iron are reduced to metals, those iron atoms that gave up their electrons are oxidized into solution as iron cations (iron chloride salts).
So here the iron will cement both gold and platinum from solution.

One reaction is more of a chemical reaction with an electron exchange.
The other is more of an electron exchange with a chemical reaction.

OK I am starting to confuse myself now.

Gold and platinum are both below iron in the reactivity series of metals.
When precipitating gold with copperas the reactivity series is not that important, the chemical reaction is different(than with cementing the metals out of solution).

Platinum is below iron in the reactivity series of metals, (so are several other metals including gold) when cementing the metals from solution, were are depending on the reactivity and use the reactivity series, iron will give up electrons to these metals below it in series and cement all of them from solution including gold, platinum, cadmium, nickel, tin, antimony copper...

Basically these are different types of electro-chemical reactions
I am getting so confused I do not know where it begins or ends

 

[Richard NL]

Dear butcher,

Please sir don't get confused or lost.(I'm the new one,You are the professional).

It begins in one sentence:
" 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)"


After several hours rereading en checking everything.
One conclusion.

Yes i did make a mistake.
Your right I messed up, i am sorry to have taken up your valuable time.
Thanks for pointing out my flaw.
Thank you Butcher for the for the detailed explanation.

Sorry.

Merry Christmas, Richard.
edit

 

[butcher]

Richard NL,

I am no professional, I am just learning like everyone else.

This is fact:
"(platinum is below iron in the reactivity series)"

But this fact has little to do with the reaction below:
"If you have gold and platinum in solution, ferrous sulfate will precipitate the gold but not the platinum"

The reactivity comes into play with platinum in solution with elemental metal Iron.
"(platinum is below iron in the reactivity series)"

I am not sure of the reaction but may look like this:
cementing platinum from solution with iron metal
PtCl6 + 2Fe --> 2FeCl3 + Pt (s)

Lets look at a aqua regia solution of gold HAuCl4, and palladium H2PdCl6, and platinum H2PtCl6.
Now we add ferrous sulfate (copperas), the gold is reduced to metal, the palladium is reduced to a lower oxidization state but stays in solution as H2PdCl4, platinum in solution is unreacted by the ferrous sulfate.
PtCl6 + FeSO4 --> No reaction
PdCl6 + FeSO4 + e- --> PdCl4 +Fe(+3) + 2Cl
HAuCl4 + 3FeSO4 --> Au (s) + 3 FeCl3+ Fe2(SO4)2 + HCl

I think the confusion came in, when I put that statement of Platinum being below iron in parenthesis, after the statement, that copperas would precipitate gold and not react with platinum in solution, I may have not said it in a way that you could easily understand what I intended to say.

No problem we are all here to learn, we just help each other learn.

 

[Richard NL]

Richard NL,

I am no professional, I am just learning like everyone else.

If everyone else was sometimes a little bit more like you,(considering learning and giving explanations) goldrefiningforum would be very different.
In that respect you are a professional.

This is fact:
"(platinum is below iron in the reactivity series)"

But this fact has little to do with the reaction below:
"If you have gold and platinum in solution, ferrous sulfate will precipitate the gold but not the platinum"

The reactivity comes into play with platinum in solution with elemental metal Iron.
"(platinum is below iron in the reactivity series)"

I am not sure of the reaction but may look like this:
cementing platinum from solution with iron metal
PtCl6 + 2Fe --> 2FeCl3 + Pt (s)

Lets look at a aqua regia solution of gold HAuCl4, and palladium H2PdCl6, and platinum H2PtCl6.
Now we add ferrous sulfate (copperas), the gold is reduced to metal, the palladium is reduced to a lower oxidization state but stays in solution as H2PdCl4, platinum in solution is unreacted by the ferrous sulfate.
PtCl6 + FeSO4 --> No reaction
PdCl6 + FeSO4 + e- --> PdCl4 +Fe(+3) + 2Cl
HAuCl4 + 3FeSO4 --> Au (s) + 3 FeCl3+ Fe2(SO4)2 + HCl

Under "normal circumstances" everything is correct.
For example exceptions:
1 mechanical drag-down.
2 Iron sulfate will also precipitate platinum from a boiling hot solution if the pH±7.
In a hurry, after denoxing a unknown solution(still hot and perhaps unnecessarily), and thinking the precipitation is gold, while in reality it is platinum.
You will by going the wrong road to recovery.

(Highest precipitation of Pt²⁺ ore PtCl⁶ = pH±8.)

I think the confusion came in, when I put that statement of Platinum being below iron in parenthesis, after the statement, that copperas would precipitate gold and not react with platinum in solution, I may have not said it in a way that you could easily understand what I intended to say.
No problem we are all here to learn, we just help each other learn.

Absolutely true.

Please correct me if I'm wrong or made a mistake, i am still learning.
B.t.w. happy new year and wish you all the best.

 

[butcher]

If you adjust the pH of your solution to neutral or on the alkaline side you will also begin to precipitate base metals and I would say it would probably be much easier to precipitate platinum.

I thought we were talking about the normal precipitation of gold from a solution like aqua regia (not salt water, or caustic salt water).

Here I did mention where you could precipitate platinum with copperas at pH 7 (salt water) But in practice I do not see any reason someone would want to.
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=48&t=11945&start=120

 

[Goldreallife]

Hello every one , I'm a new here
Does the ferrous sulphate drop pure gold or with other metals especially copper ? , and is the adding of ferrous sulphate will be by parts step by step or only one time in one add ?
and how can I know when I should stop from adding ?
Thank you