# how to(method) refine gold and silver from a bar??



## anands138 (Dec 24, 2012)

Hey everyone,

I have a scrap gold bar of 10 kg which contains 40% silver and 60% gold. purity 14k.

I would like to know the best process to refine the scrap gold bar and recover both the silver and gold from it.

Thank you

Anand


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## Geo (Dec 24, 2012)

in my inexperience, i would think you will need to melt it and recast into a size thats more manageable. after you get the bar into smaller increments, finish inquarting the gold by adding enough silver to make the content of the mix 75% silver and 25% gold. then you can digest the alloy in nitric acid leaving nearly pure gold and reclaiming the silver by cementing it out of solution onto copper.


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## FrugalRefiner (Dec 24, 2012)

The silver content will cause problems in the current ratio. I would suggest inquarting and cornflaking. Then digest in nitric acid. Decant the solution. The silver can be recovered from the solution by cementing with copper. The gold can then be digested in AR or HCl/Clorox, and precipitated with the reducer of your choice.

Since you've just joined the forum, I realize some of the terminolgy may not be familiar to you. The description above is just a very brief outline. Use the forum Search function to learn the details of these processes. There is much to learn before you attempt any of these procedures.

Dave

Looks like Geo beat me to it again! :lol:


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## butcher (Dec 24, 2012)

The best advice I can give is to begin studying Hokes book and the forum, the process to separate gold and silver, and then refine the gold although simple, does have a awful lot of details you will need to understand, it will take time to learn all of these details.

This is not like asking how to bake a cake.
It is like asking how do I become a scientist skilled in the art of refining, and learn the science of gold recovery and refining.


A short overview of the process:
Calculate gold content.
In-quarter the metal,
Pour Shot,
Part the metals in nitric.
(Recover silver from silver nitrate, wash dry melt and reuse silver or refine silver in electrolytic cell).
Wash gold,
Put gold into solution.
Denox the gold chloride solution.
Precipitate gold from solution.
Testing the solution for valuable metals.
Wash gold.
Then refine it all over again. 
Wash gold. 
Dry.
Melt,

It is better to spend a lot of time studying, doing small experiments to get an understanding of the chemistry and processes, and learning before trying things you do not understand, or you just think you understand, and then to find out it is not as simple as you thought, wondering where all of your gold went to. And later find out you just made a big mistake jumping off the boat without learning to swim first, and threw away all of your gold?
You can lose a lot of gold in a process you do not understand


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## goldsilverpro (Dec 24, 2012)

anands138 said:


> Hey everyone,
> 
> I have a scrap gold bar of 10 kg which contains 40% silver and 60% gold. purity 14k.
> 
> ...


The karat of this is higher in gold than plumb 14K (58.33%). I've never seen jewelry that runs higher than plumb and have rarely seen it that is plumb. It's usually less than plumb and is often from 1/2 to 1 karat lower. The mix you describe would be green gold. Most often, along with high silver, green gold contains a little copper and/or zinc.

Assuming your figures are correct, here's the process. This is only a general description. The details can be found elsewhere on this forum and in the Hoke book. 

As it sits, the gold won't dissolve in aqua regia because the silver is greater than 10%. The silver won't dissolve in nitric because the gold is greater than 25%. Therefore, the best way would be to melt it with an additional 14kg of silver (inquart it). This would reduce the gold to 25%. Then, shot it and dissolve the silver completely with 50/50 nitric acid. The gold residue is purified by separating it from the nitric solution, dissolving it in aqua regia, and dropping the gold with a sulfite (usually). The silver is collected from the nitric solution by cementing it on pure copper slabs or bus bar. With proper rinsing, the silver should be about 99% pure. The silver can then be further purified by melting and casting it into proper sized bars and running it through a silver cell. If the silver will be re-used for inquartation of future lots, purification in a silver cell isn't necessary.

To dissolve the 18kg of silver, it will take about 22 liters of 70% nitric acid and 22 liters of distilled water. To dissolve 6kg of gold, it will take about 23 liters of hydrochloric and 5 liters of 70% nitric. These acid figures aren't exact and are dependent on such things as your setup and the acid strengths. It will take about 6kg of SMB or sodium sulfite to drop the gold. To purify the 18kg of silver, it would take about 8-10 days, 24/7, in a 5 gallon Thum silver cell. You would need a fair sized crucible furnace, molds, tongs, furnace gloves, and other furnace equipment. You would need dissolving containers - probably stainless for the nitric and glass for the aqua regia (I would use 4000ml beakers in 5 liter pyroceram Corning Ware dishes). There are a lot of other incidentals you will need, like hot plates an a stainless shotting container. And, of course, you would need a good fume hood, furnace exhaust, knowledge and expertise. Are you sure you're up to this?


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## anands138 (Dec 26, 2012)

thanks everyone for the answers.

i read the hoke's book and got a lot of detailed information from it. it was very helpful

thanks for the support.

anand


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## kahkushan (Jan 4, 2013)

anands138 said:


> Hey everyone,
> 
> I have a scrap gold bar of 10 kg which contains 40% silver and 60% gold. purity 14k.
> 
> ...



you mean you have 4 kg of silver & 6 kg of gold.

I have done this kind of refining it works 100%.
in this process you need 2X of gold, i mean if you need to make 6kg of 24k gold you need 12 kg of silver.
you have 4 kg in your bar then you need kg more.
melt & mix the both then desolve in solution of nitric acid. it will be desolve easily. once you will heat the solution it will give brown smoke when smoke will white gold particle will settle down. silver will be in liqued form.

Collect the gold & melt this using your prefered method & it is 99.5% gold. silver can be recycled by adding table salt to the solution.


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## butcher (Jan 4, 2013)

Notice the very valueable information our professional refiner has given you, GSP said you will also need knowledge and expertise, this is very important, it will take study to gain this, the information is available here on the forum, but you will not get it from asking a question and getting an answer, it will take work of study and research, and then practice working with what you have studied.

You are dealing with a considerable amount of values, it will take considerable study to learn to get the most from these values without losing them in the process, your best bet is to spend time studying to get the knowledge you need to deal with what you have properly.

Asking a question in a post, and getting a simple answer and trying to begin working from there would only lead to problems, you need to get an understanding of the basics of recovery and refining first (Hokes book), and then learn which process to use for what material you have, and have an understanding of the whole process (which can be learning several processes to recover and the refine the values depending on what material your working with).

Jumping into to something you do not quit understand yet can be a costly mistake, and will make it harder to learn in the long run, because you will be wasting your time looking for the gold you lost, and trying to find ways to get out of a mess you got yourself into.

Read Hokes and study the forum. 

You will learn how to recover and refine your gold to high purity.


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## fasTTcar (Jan 4, 2013)

anands138 said:


> Hey everyone,
> 
> I have a scrap gold bar of 10 kg which contains 40% silver and 60% gold. purity 14k.
> 
> ...



Are you sure there are no other alloys in it? If it was just straight 14k jewellery, it may very well have some copper and other elements in it as well.


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