will ferrous sulphate drop the gold???

[Goldreallife]

Hello every one
I'm newbie here
Just I want to ask what's the best , SMB or Fr Sulphate ?
And how I can precise the quantity ?
Another thing , is H2O2 can drop the gold in AR solution ?
Thank you every one .

 

[FrugalRefiner]

Goldreallife, welcome to the forum. Please try to keep like discussions in the same thread. The more information is spread throughout the forum, the more difficult it is to follow it.

Many prefer ferrous sulfate for dirty solutions.

Precise quantities depend on many factors like other metals in solution, oxidation states, etc. As a general "rule of thumb", expect to use a gram or so of either for each gram of gold. Add your reduction agent, mix well, allow to settle, then test the solution with stannous to see if you need to add more.

I'm not familiar with using H₂O₂ to precipitate gold.

Dave

 

[g_axelsson]

Yes, H₂O₂ can be used both to precipitate or dissolve gold. If I remember correctly it depends on pH if it is a reducer or oxidizer.

I read about it eight years ago so I don't remember the details any longer and I have only user hydrogen peroxide to dissolve gold, never to precipitate it.

Göran

 

[Goldreallife]

Thank you very much you are very helpful , thanks again

 

[Lino1406]

Ferrous sulphate with its associated water molecules - 4.5 g per 1g gold. SMB indeed 1g per 1g gold. Ferrous sulphate is more selective and not smelling

 

[Ehsan Ebrahiminia]

I used iron sulfate solution of aqua regia to deposit gold, but very little amount of gold was deposited. what is the problem ?

 

[Yggdrasil]

I used iron sulfate solution of aqua regia to deposit gold, but very little amount of gold was deposited. what is the problem ?

Welcome.
You do not give enough information for us to help you.
Source of material, how did you make the AR and so on is needed.

Here is for your studies.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library

https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

 

[Ehsan Ebrahiminia]

Welcome.
You do not give enough information for us to help you.
Source of material, how did you make the AR and so on is needed.

Here is for your studies.

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: Screen Readable Copy of Hoke's Book
2. Then read the safety section of the forum: Safety
3. And then read about "Dealing with waste" in the forum: Dealing with Waste

Suggested reading: The Library

https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

I used one part nitric acid and three parts hydrochloric acid to make the solvent. Some gold powder with 2 grams of copper powder was dissolved in acid. Then I neutralized it with urea and added 400 cc of 15 g/l iron sulfate solution to it

 

[Yggdrasil]

I used one part nitric acid and three parts hydrochloric acid to make the solvent. Some gold powder with 2 grams of copper powder was dissolved in acid. Then I neutralized it with urea and added 400 cc of 15 g/l iron sulfate solution to it

Making AR that way is wasteful and do precipitation more complicated.
We also consider the use of Urea in refining as less than optimal.
Urea belongs in the garden.
If you prepare the AR like this you will have little use for deNOxing the solution.
Add HCl in excess like cover your material,
then add Nitric in small batches no more than 0.5ml per gram of expected Gold in the first addition, then add small additions until no more reaction or all material is dissolved.
If you accidentally add too much Nitric you can decompose the Nitric with Sulfamic acid at appr 90C.
One issue with Urea is that it is slightly caustic and as such can rise the pH too much, another one is that under certain conditions it may form an explosive compound.

Was this clean Gold powder and Copper powder?

Now go and study what you have been given in my previous reply.

 

[Willy bikaka]

"Ferrous sulphate " or "green vitro " or " Copperas" ___Whatever you may call It ,is a better option I also have used successfully and what I like about it is how easy it is to make it in situ!.I use to dissolve iron binding wires in the battery acid(which is dilute sulphuric) and let the metal dissolve to saturation and get the green solution(Copperas) !!..to have it more clean I use cotton to filter the carbon dusts that drop out of steel .
NOTE:
Ferrous sulphate drops gold from chloride medium.NOT Cyanide medium!!....It drops Gold chloride NOT gold from Aurocyanide!!

 

[Yggdrasil]

"Ferrous sulphate " or "green vitro " or " Copperas" ___Whatever you may call It ,is a better option I also have used successfully and what I like about it is how easy it is to make it in situ!.I use to dissolve iron binding wires in the battery acid(which is dilute sulphuric) and let the metal dissolve to saturation and get the green solution(Copperas) !!..to have it more clean I use cotton to filter the carbon dusts that drop out of steel .
NOTE:
Ferrous sulphate drops gold from chloride medium.NOT Cyanide medium!!....It drops Gold chloride NOT gold from Aurocyanide!!

Keep Cyanide out of reach of any acidic substances!!!
The question replied to was about Ferrous Sulfate, and why the Gold do not drop.
We still have not enough info on that part yet.

 

[Anil]

I used one part nitric acid and three parts hydrochloric acid to make the solvent. Some gold powder with 2 grams of copper powder was dissolved in acid. Then I neutralized it with urea and added 400 cc of 15 g/l iron sulfate solution to it

Please check the PH of the solution after removing excess HNO3 with Urea. The PH should be preferably less than 2 for successful precipitation of Gold from Gold Chloride solution.

 

[Anil]

Making AR that way is wasteful and do precipitation more complicated.
We also consider the use of Urea in refining as less than optimal.
Urea belongs in the garden.
If you prepare the AR like this you will have little use for deNOxing the solution.
Add HCl in excess like cover your material,
then add Nitric in small batches no more than 0.5ml per gram of expected Gold in the first addition, then add small additions until no more reaction or all material is dissolved.
If you accidentally add too much Nitric you can decompose the Nitric with Sulfamic acid at appr 90C.
One issue with Urea is that it is slightly caustic and as such can rise the pH too much, another one is that under certain conditions it may form an explosive compound.

Was this clean Gold powder and Copper powder?

Now go and study what you have been given in my previous reply.

The most appropriate reply to the query. Thank you, Sir.

 

[Ehsan Ebrahiminia]

Thank you for your time
Honestly, I dissolved a certain amount of pure gold in aqua regia and neutralized it by heating and adding hydrochloric acid and precipitated the gold with the iron sulfate solution. I also added iron sulfate to the amount of two parts expected to make sure that nothing remains in the solution.
But in the end, eighty percent of the gold was recovered?
what is the problem ?

 

[Yggdrasil]

Thank you for your time
Honestly, I dissolved a certain amount of pure gold in aqua regia and neutralized it by heating and adding hydrochloric acid and precipitated the gold with the iron sulfate solution. I also added iron sulfate to the amount of two parts expected to make sure that nothing remains in the solution.
But in the end, eighty percent of the gold was recovered?
what is the problem ?

Did you test with Stannous before and after precipitation?

 

[Ehsan Ebrahiminia]

Did you test with Stannous before and after precipitation?

Yes
Before deposition, the test was positive and after deposition, the test was negative

 

[Yggdrasil]

Yes
Before deposition, the test was positive and after deposition, the test was negative

That is strange, are you sure the Gold was pure?
Did you evaporate to dryness when driving off the Nitric.

 

[Ayham Hafez]

He asked about dissolving Ferrous sulfate in water before add to aquaregia to drop gold, any body have any idea is that also work?

I tried once upon time to dissolve ferrous sulfate in water then add to aquaregia, but after dissolving it in water I got a brownish color so I decided to add solid ferrous sulfate directly to aquaregia, so I didn't notice if gold has been dropped with Ferrous sulphate dissolved in water or with solid ferrous sulfate.

 

[Yggdrasil]

He asked about dissolving Ferrous sulfate in water before add to aquaregia to drop gold, any body have any idea is that also work?

I tried once upon time to dissolve ferrous sulfate in water then add to aquaregia, but after dissolving it in water I got a brownish color so I decided to add solid ferrous sulfate directly to aquaregia, so I didn't notice if gold has been dropped with Ferrous sulphate dissolved in water or with solid ferrous sulfate.

If dissolved or not should not make much of a difference.
If it gets brown in water it might be oxidised and then it do not work.
Are you sure all the Nitric and NOx are destroyed?

 

[Shark]

If the ferrous sulfate is questionable, I do this anyway, mix it with hot water, then add a small amount of hydrochloric acid, add until it turns a slight greenish color.
Wild it to add:
It should not take much HCl to change the color, if it does your ferrous sulfate is to oxidized.

Better yet, dissolve it, filter well, then recrystallize it, and add just enough sulfuric acid to make it damp.