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Electrochemistry Processing anode slime from silver cell
- Thread starter ron c
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samuel-a
Well-known member
- Joined
- Oct 7, 2009
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Processing anode slimes:
a- Let the anode bags with slimes dry up.
b- Incinerate the anode bag and powder (if you use a torch, be careful not to blow away the very fine powder)
c- Cover with 50/50 nitric and boil for 5-10 minutes. This step will remove left over silver, copper and palladium.
d- Upon cooling and settling, decant the bulk of the solution and pass it on to recover the above mentioned values. Repeat this nitric leach if needed.
e- Wash the left over powder with d. water once or twice (this is optional if you can't or won't wait for it to settle nicely to the bottom, but bare in mind it may have consequences later on in this process)
f- Cover the powder with HCl and slowly heat the beaker.
g- Once hot, start adding nitric acid drop wise and notice the reaction. Keep adding nitric acid until no more solids dissolve (remember that in most cases, you will end up with some silver chloride, so don't mistake it to be gold or platinum)
h- When dissolution is over and the beaker had cooled slightly, add some ice cubes and water, enough to dilute the solution 3-4 times over and let it sit for about 20-30 minutes
i- Filter the solution while it is still somewhat cold, that should rid the solution of silver almost completely.
j- Precipitate the gold with SMB.
k- The following day, seperate the gold powder from the liquid and test the solution with SnCl for dissolved platinum. If positive for Pt, add Aluminum or Zinc shaving to cement it (careful, H2S gas released in this reaction).
end products:
A solution of Ag, Cu and Pd and maybe some Pt (step c)
gold powder (step j)
platinum powder (step k)
Collect and accumulate these products for later refining.
Good luck
Sam
a- Let the anode bags with slimes dry up.
b- Incinerate the anode bag and powder (if you use a torch, be careful not to blow away the very fine powder)
c- Cover with 50/50 nitric and boil for 5-10 minutes. This step will remove left over silver, copper and palladium.
d- Upon cooling and settling, decant the bulk of the solution and pass it on to recover the above mentioned values. Repeat this nitric leach if needed.
e- Wash the left over powder with d. water once or twice (this is optional if you can't or won't wait for it to settle nicely to the bottom, but bare in mind it may have consequences later on in this process)
f- Cover the powder with HCl and slowly heat the beaker.
g- Once hot, start adding nitric acid drop wise and notice the reaction. Keep adding nitric acid until no more solids dissolve (remember that in most cases, you will end up with some silver chloride, so don't mistake it to be gold or platinum)
h- When dissolution is over and the beaker had cooled slightly, add some ice cubes and water, enough to dilute the solution 3-4 times over and let it sit for about 20-30 minutes
i- Filter the solution while it is still somewhat cold, that should rid the solution of silver almost completely.
j- Precipitate the gold with SMB.
k- The following day, seperate the gold powder from the liquid and test the solution with SnCl for dissolved platinum. If positive for Pt, add Aluminum or Zinc shaving to cement it (careful, H2S gas released in this reaction).
end products:
A solution of Ag, Cu and Pd and maybe some Pt (step c)
gold powder (step j)
platinum powder (step k)
Collect and accumulate these products for later refining.
Good luck
Sam
