# Process to convert silver sulphide into metalic silver



## Juan Manuel Arcos Frank (Dec 10, 2009)

Here is my process to convert silver sulphide to metalic silver.

Originally I wrote it in WORD format,but it was 30 MB so I changed it to PDF,but I am such an idiot working with computers so the pics move a little bit,so I offer an apology.

This process is dedicated to GSP,My Dear Friend.

I hope this process will be useful to all the Members of the Forum.

Kindest regards.

Manuel


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## Rhodium (Dec 10, 2009)

Nice job Manuel.


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## golddie (Dec 10, 2009)

I know silver nitrate
silver chloride
How do I get silver suplhide


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## Juan Manuel Arcos Frank (Dec 10, 2009)

Rhodium:

You are welcome,it is my pleasure.One day,I will learn how to make better post with PDF,I hope.

Have a nice day

Manuel


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## Juan Manuel Arcos Frank (Dec 10, 2009)

Golddie:

It is very easy...when you have silver in solution (i.e.silver nitrate in water/acid solution,silver complex cyanide solution or silver thiosulfate complex which is common fixer) just add some sodium sulphide (hydrosulphide acid will work too,but it has a strong oddor of rotten eggs) and you will see that a black mud is formed...this black mud is silver sulphide.

If you find a silver mine,you will see some black powder line between rocks...this is silver sulphide.

Best regards

Manuel


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## 4metals (Dec 10, 2009)

In the process of removing excess silver chloride when digesting karat jewelery containing diamonds I generate a waste solution of sodium thiosulphate which is loaded with silver. (the thiosulfate dissolves the silver chloride and a very small percentage of the gold) Generally we just evaporate off the water and dry the powder and incinerate to make a sweep. Converting it to silver sulphide with sodium sulphide may be stinky but worth a try. Then the silver can be extracted from the muds directly.

Plus the rotten egg smell is most likely a water scrubbable fume. Worth playing with.

Thanks Manuel


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## Juan Manuel Arcos Frank (Dec 12, 2009)

4metals:

You are right,but you can avoid nasty rotten eggs odor controling sodium sulphide adittion.The trick is just adding the exactly quantity that you have of silver...I mean,if you check your silver content then add exactly the same weight of sodium sulphide...here is why I think it happens:

Sodium sulphide reacts with the silver thiosulfate complex to form silver sulphide and regenerates the sodium thiosulfate.

The bad reaction is that sodium sulphide reacts with water to form hydrogen sulphide that smells like hell,so do not add more than needed.

You can check the silver content using a copper wire.

4metals,a pleasure talking with you.

Have a a nice day.

Manuel


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## 4metals (Dec 12, 2009)

Manuel,
That's a good tip, the copper wire is coated by any silver in solution so just adding sodium sulfide slowly and checking with copper can minimize the stink. 

I've already used your method to convert some silver sulphide, did it in an incinerator to control the heat, 20 pounds of damp sludge reduced in a refractory cement tray. Skimmed off the slag and let it cool, too awkward to pour out of the tray, the silver was sitting as a slab on the bottom. 

Already thinking of a tray with a sloped bottom and a trough so the silver collects in an easier to remelt bar.


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## butcher (Dec 12, 2009)

some great information manuel, very nice job, are those melting dish's homade or made locally?

I have been working on your challenge to come up with some caveman chemical, for gold refining.


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## Juan Manuel Arcos Frank (Dec 13, 2009)

4metals:

I am glad that this process is useful for you.

Kindest regards.

Manuel


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## Juan Manuel Arcos Frank (Dec 13, 2009)

Butcher:

Those dishes are called "copelas" (in Spanish),they are handmade and made of clay.In these dishes are melted gold and silver here in Mexico and they are very cheap,one like the pics cost me 8 pesos (0.60 USD).The trick is to treat it with borax,otherwise it breaks in a few minutes.Here is the way I do it:

Heat with the torch at medium heat level,front and behind.

Add borax and melt it,once that it is liquid cover all the dish letting the metled borax to fluid.

The dish seems like having some kind of glass film which protects it.

Butcher,I am waitting for your process to manufacture some banned chemcial substance.

Have a nice day.

Manuel


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## catvet (Dec 26, 2010)

Manuel

I would like to say thankyou for taking the time to post this process.

I am a hobbyist (ie small amounts) and used your process today for the first time with great success. It is so easy and quick!!

For those of us processing small amounts (mine was 1oz of silver) a MAPP torch works fine for this process.

Many thanks
Marcus


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## Juan Manuel Arcos Frank (Dec 27, 2010)

Marcus:

It is my pleasure...try to find the biggest bottle of whisky,run,cognac,brandy,vodka,gin,wine or beer and say CHEERS!!!!! to me.

As you can see I live in Pachuca,Mexico,where do you live?

Kindest Regards.

Manuel


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## HAuCl4 (Dec 27, 2010)

Interesting process. Thanks!.

One thing I will say: H2S (rotten egg smelling gas) is about the most poisonous gas known to man. Very small % concentrations are lethal. Be *VERY* careful!.


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## catvet (Dec 28, 2010)

Hi Manuel

A toast of cognac to you!!

I am far far away from you, in Brisbane Australia.

I did not notice any smell of H2S, although it was a windy day and the process was done outside.

I am not sure what the gas is but I did not expect H2S with the reagents being Ag2S and KNO3. I expected either NOx or SOx or a mix of these and some kind of K compound going into the flux. If I am lucky someone knowledgable will know the reaction products.


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## HAuCl4 (Dec 28, 2010)

This process done in medium sized batches can generate enough H2S to kill the operator, if the fumes aren't properly handled. H2S in higher concentrations will not give you the chance to smell it!. *Highly dangerous!.*

edit: Any process that can generate H2S should be treated with the same care as a process that can generate HCN. They are about as toxic.


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## catvet (Dec 28, 2010)

Hi HAuCl4

Noted to always be aware of the fumes.

I am a novice in this field and am interested in the chemistry behind the processes.

Can you tell me where the H comes from to make the H2S? Is it from any residual water? Perhaps that in hydrated borax? Unburnt gas from the torch?

Thanks
Marcus


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## HAuCl4 (Dec 29, 2010)

Marcus: There are a couple of posts above where 4metals and Manuel discuss a variation of the process that generates H2S as a by-product. The original process does not, except if any acid or maybe water gets in there somehow by accident you can have the extra hydrogen you need to get killed. :shock:


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## Juan Manuel Arcos Frank (Dec 29, 2010)

Marcus:

HAuCl4 is right about H2S,it is very toxic and atrophy the sense of smell,you are told not to generate it,the trick is using just Na2S as needed.H2S is formed with water + Na2S so try to avoid any excess.

I send you a big hug to Brisbane.

Regards.

Manuel


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## goldsilverpro (Dec 29, 2010)

Excellent write-up, Manuel. I plan on using it.


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## Juan Manuel Arcos Frank (Dec 29, 2010)

GSP,my Dear Friend:

You are welcome.

Have a nice day.

Your friend:

Manuel


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## Drewbie (Feb 8, 2011)

One question Manuel,

Can sodium nitrate be used instead of potassium nitrate?

Saludos,


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## Juan Manuel Arcos Frank (Feb 10, 2011)

Drewbie:

I do not think so...try to find potassium nitrate,ii is a common fertilizer.

Te mando un abrazo.

Manuel


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## abnasc (Mar 14, 2011)

Manuel,

Have you used your process to get metallic silver from quartz ores' silver sulphides?

Gracias

Alexandre


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## Juan Manuel Arcos Frank (Mar 15, 2011)

Alexandre:

No,I have not used it for ores.

I think it will be very expensive because you will have to melt tons of ore.As far as I know,roasting process works better than my porcess.

I use my process for silver recovery from photo fixers.I am posting for you a book for silver sulfide ores.

http://www.archive.org/stream/hydrometallurgy02hofmgoog/hydrometallurgy02hofmgoog_djvu.txt

I hope it helps.

Kindest regards.

Manuel


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## terrypayton (Aug 20, 2011)

Hi Manuel, we were able to use your process for the mud. It worked perfectly. Thank you.

I'm a little stuck on what to do to make the "mud". We have solution where everything has already "fell" to the bottom over a period of a long time. The mixture at the bottom is extremely silver and shining. Not sure what that is. When you put copper in the solution it does not plate the copper, so we believe it's out of it and all at the bottom in the silver mixture. However, if we do your process or just melt the silver mixture by itself, nothing happens but evaporation. 

Do you have any idea of what this is and how to get it into the form of the "mud" in the most efficient and timely way? Once we do, obviously we can use your method to turn it to silver.

Thanks again for your help on this.


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## terrypayton (Aug 20, 2011)

We were just messing with the silver colored solution at the bottom of the spent solution. We added lye and syrup to the solution with water and waited and it dropped out little black specs along with some grey specks. Then we went it and used your method of adding the pottasium nitrate and we got silver. So I guess the question is still what do we have and how can we get the silver out of it efficiently? Confused of course... thanks for the help.


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## Juan Manuel Arcos Frank (Aug 21, 2011)

Terrypayton:

If copper wire does not get gray/silvered it means that there is not any silver in solution,so pour off the liquid,filter the mud and dry it by any known method(you can just put it in the sun).This mud is a mixure of sulphides(among silver sulphide) and sulphur.

You can use my process for silver sulphide or you can use AR to convert all sulphides into chlorides so you will get silver chloride+sulphur,as a gray mud but the only way to convert it to metallic silver is melting with sodium carbonate,I do not know why but do not use cementation,lye or any other process to convert it to metallic silver,probably sulphur interferes with these processes.

Keep us posted about your progress.

Kindest regrads.

Manuel


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