New Refining Equipment

[grainsofgold]

Usually make a steel wool canister that used to be made for recovering silver from dental xray processing labs. The solution is slowly run through and the silver remains just as the silver thiosulfate from the film developing remained.

Then when the cartridge is full, melt it with steel rebar to reduce the silver back to silver metal and pour a silver bar.

I always pour the acid with the silver chloride and insolubles through a 100 micron polypro screen to separate all of the loose Silver Chloride from the crusty stuff. The loose chlorides are stored under a inch of so of water in a dark bucket until I have enough to reduce back to silver.

By screening out the bulk of the Silver Chloride the amount left encrusting the gold is greatly reduced so the canister lasts a long time.

What acid are you pouring with the AgCl ? Aqua Regia ?

When melting the steel wool with the silver you say to melt with steel rebar - Can you please elaborate- It’s not clicking with me sorry.

With the silver chloride that is broken down off the encapsulated gold , i tend to shake it and it falls off the gold for the most part. Can’t this fallen silver be washed with distilled water , roasted then put in a beaker of Nitric /H2o Distilled then cemented out with copper ?

thanks in advance.

GOG

 

[Yggdrasil]

What acid are you pouring with the AgCl ? Aqua Regia ?

When melting the steel wool with the silver you say to melt with steel rebar - Can you please elaborate- It’s not clicking with me sorry.

With the silver chloride that is broken down off the encapsulated gold , i tend to shake it and it falls off the gold for the most part. Can’t this fallen silver be washed with distilled water , roasted then put in a beaker of Nitric /H2o Distilled then cemented out with copper ?

thanks in advance.

GOG

Silver can, Silver Chloride can’t since it is insoluble in all acids.

 

[4metals]

When the encrusting silver is tumbled in sodium thiosulfate, it produces a silver thiosulfate just like developing film does. That solution, which is not silver chloride in acid, is poured through a steel wool canister. The Silver is caught in the canister and when the canister is loaded it is melted with steel rebar in the melt to reduce the silver in the canister to metallic silver.

 

[kurtak]

When the encrusting silver is tumbled in sodium thiosulfate, it produces a silver thiosulfate just like developing film does. That solution, which is not silver chloride in acid, is poured through a steel wool canister. The Silver is caught in the canister and when the canister is loaded it is melted with steel rebar in the melt to reduce the silver in the canister to metallic silver.

To add to &/or clarify what 4metals posted here when dealing with the silver chloride (residue) resulting in processing karat scrap

Some refiners will use ammonia (a base) to dissolve the silver chloride (such as an ammonia wash on their gold sponge) & then re-precipitate silver chloride from the ammonia wash with HCl

If you use sodium thiosulfate (also a base) to dissolve the silver chloride it results in a silver thiosulfate solution which is commonly used for the old black & white picture fixer solutions

From wiki --- Silver halides, e.g., AgBr, typical components of photographic emulsions, dissolve upon treatment with aqueous thiosulfate.This application as a photographic fixer was discovered by John Herschel. It is used for both film and photographic paper processing; the sodium thiosulfate is known as a photographic fixer, and is often referred to as 'hypo', from the original chemical name, hyposulphite of soda.

So - once you have the silver sulfate solution you can recover the silver from the solution with steel wool (a cementing process)

However - the steel wool does not reduce the silver in solution to actual silver like cementing silver with copper from a nitrate solution

Rather - the steel wool reduces the silver sulfate (solution) to silver sulfide (a solid silver compound of silver plus sulfur)

So - to reduce the silver sulfide you do so by smelting it with soda ash as your flux & iron (rebar or nails etc.) as the reducer in the smelt as the sulfur reacts with the iron in the smelt --- somewhat like carbon in a smelt will reduce metal oxides (copper/silver) &/or like reducing silver chloride by tumbling it with iron & sulfuric acid (ion exchange reactions)

So the process is --- dissolve the silver chloride with sodium thiosulfate which gives you a silver sulfate solution

Then reduce the silver sulfate to silver sulfide by cementing with steel wool

Then reduce the silver sulfide by smelting with soda ash & iron (rebar or nails etc.)

This will give you a very near pure (if not pure) silver end product

As a word of warning --- during the smelting process the nails (if you use "large" spikes) &/or the rebar will start to drill holes in the bottom of the crucible (thereby shortening the crucible life) - you can reduce this effect (of drilling holes in bottom of crucible) by bending (curling) up the end of the rebar (or "large" spikes) that sit in the bottom of the crucible

You want the rebar &/or large spikes long enough that they stick out above the crucible so that you can pull them out before making your pour

The advantage to dissolving the silver chloride with sodium thiosulfate instead of ammonia is you don't have to deal with the VERY nasty ammonia fumes &/or the concern of creating explosive ammonic silver compounds

For what it is worth

Kurt

 

[grainsofgold]

thank you all.