# Separate gold and silver powder?



## SweetGold (May 25, 2011)

How does mixed silver and gold powder get separated? The assumption is both are 999 and 24K respectively. Are there several methods?


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## goldsilverpro (May 25, 2011)

Assuming the mix is made up of separate Au or Ag particles and not an alloy of these metals, hot concentrated (about 67% to 70%) nitric acid, first diluted with an equal volume of distilled water, will dissolve the silver but not the gold. It will take about 2.5 ml of this diluted nitric to dissolve 1 gram of 999 silver. After dissolving, the silver can be recovered by placing copper, usually in the form of clean copper tubing, copper buss bar, or solid copper wire, in the solution. This process is called cementation and much has been written about it on this forum.

This process also works on Au/Ag alloys if there is at least 3 times as much silver in the alloy as there is gold.


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## Irons (May 25, 2011)

Be sure to filter out the Gold from the solution before putting in the Copper, or you will get back your mixture of Gold and Silver powder. :mrgreen:


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## SweetGold (May 25, 2011)

goldsilverpro said:


> Assuming the mix is made up of separate Au or Ag particles and not an alloy of these metals, hot concentrated (about 67% to 70%) nitric acid, first diluted with an equal volume of distilled water, will dissolve the silver but not the gold. It will take about 2.5 ml of this diluted nitric to dissolve 1 gram of 999 silver. After dissolving, the silver can be recovered by placing copper, usually in the form of clean copper tubing, copper buss bar, or solid copper wire, in the solution. This process is called cementation and much has been written about it on this forum.



Funny, I just watched your video on the silver recovery with nitric acid. (Great stuff, btw!  ) However, there you ended up with silver chloride. Here you're saying to use copper as a collector? I guess I will have to look into the cementation process. Though actually Im more interested in recovering the gold haha....



> This process also works on Au/Ag alloys if there is at least 3 times as much silver in the alloy as there is gold.



What if it isnt? Let's say its 1:1, what process would you have to use then? 



Irons said:


> Be sure to filter out the Gold from the solution before putting in the Copper, or you will get back your mixture of Gold and Silver powder. :mrgreen:



Yes, the gold hehe... . So how do I filter the gold out of the nitric acid solution? Preferably without losing any of the silver - though as I stated, Im not that concerned about it. Thanks!


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## goldsilverpro (May 25, 2011)

That was lazersteve's silver video and not mine.

If the powder is a 1:1 Au/Ag alloy, you would need to add enough silver, by melting it all together, to make the alloy at least 3 parts silver to 1 part gold. After melting, the molten metal should be poured into a deep container of water. This will increase the surface area and will make the dissolving go faster.


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## SweetGold (May 30, 2011)

goldsilverpro said:


> That was lazersteve's silver video and not mine.



Sorry for the mix up! Forgive a newbie.  So my compliment goes to lazersteve instead. :lol: 



> If the powder is a 1:1 Au/Ag alloy, you would need to add enough silver, by melting it all together, to make the alloy at least 3 parts silver to 1 part gold. After melting, the molten metal should be poured into a deep container of water. This will increase the surface area and will make the dissolving go faster.



Do you think commercial refiners would go through such trouble if the alloyed powder amount was just a few grams?


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