Zinc copper silver
- Thread starter cerise
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Salt works, but complicates the process excessively. Recovery on copper is fast and easy. Not suggesting, not for a moment, that salt doesn't do the job---just that most of us prefer to avoid silver chloride as much as possible. You'll come to appreciate that concept when you get deeply involved with silver chloride.cerise said:
Harold
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It's not particularly dangerous to work with---just more work that is required. Once you have silver in solution, it's readily recovered as elemental silver on copper. The only real downside is that you use copper and it's not recovered in a form that's readily marketed, but that's not impossible, either.
I refined for over 20 years, and used copper almost exclusively. There were exceptions---such as when I had such a dirty solution that cementing the silver dragged down a huge amount of material I'd rather leave behind. In that case, I'd use HCl, which insured that it all stayed in solution and was easily washed out of the resulting silver chloride.
Silver chloride is a nuisance to handle---especially when you have options that eliminate the stuff. It's bulky and requires steps that are eliminated by the use of copper.
Bottom line---it's a judgment call--one that you alone must make. Most of us that have refined commercially try to avoid the stuff. You may see it differently. There is no right and wrong in this issue---just need and convenience. I think GSP would agree with my comments. Both of us avoided silver chloride as much as we could.
There is one real benefit to using copper. Silver is known to be a carrier of the platinum group of metals, some of which readily dissolve in nitric. Even platinum will dissolve in nitric when it's alloyed with silver. By cementing with copper, the values are extracted from the solution, then recovered from the slimes of the silver cell. It's a great way to concentrate low volumes of the metals, and eliminates the base metals in the process.
Harold
I refined for over 20 years, and used copper almost exclusively. There were exceptions---such as when I had such a dirty solution that cementing the silver dragged down a huge amount of material I'd rather leave behind. In that case, I'd use HCl, which insured that it all stayed in solution and was easily washed out of the resulting silver chloride.
Silver chloride is a nuisance to handle---especially when you have options that eliminate the stuff. It's bulky and requires steps that are eliminated by the use of copper.
Bottom line---it's a judgment call--one that you alone must make. Most of us that have refined commercially try to avoid the stuff. You may see it differently. There is no right and wrong in this issue---just need and convenience. I think GSP would agree with my comments. Both of us avoided silver chloride as much as we could.
There is one real benefit to using copper. Silver is known to be a carrier of the platinum group of metals, some of which readily dissolve in nitric. Even platinum will dissolve in nitric when it's alloyed with silver. By cementing with copper, the values are extracted from the solution, then recovered from the slimes of the silver cell. It's a great way to concentrate low volumes of the metals, and eliminates the base metals in the process.
Harold
Precipitating the Silver with copper should produce 98-99% pure Silver so long as you have washed the Silver properly.
To get it beyond the 98-99% and up in to the 99.99% range you will need to further refine the Silver using an Electrolytic Thumb Cell,
it's really the only way to get 99.% + Silver, unlike Gold which can be made purer by a range of techniques but to get pure Silver it can only really be achieved with a Thumb Cell.
To get it beyond the 98-99% and up in to the 99.99% range you will need to further refine the Silver using an Electrolytic Thumb Cell,
it's really the only way to get 99.% + Silver, unlike Gold which can be made purer by a range of techniques but to get pure Silver it can only really be achieved with a Thumb Cell.
