Electrical contacts

[cheechQ]

I processed 90 g of electrical contact tips everything went good got 26 g of silver. I used nitric acid 50% and 50% water when the reaction was done I filter the solution and got a brown substance left behind any idea of what it could be.

 

[jonn]

May be gold, or dirt. Incinerate it all including the filter, run the solids through hcl then AR. Use stannous test .

 

[Pantherlikher]

My best guess....being new... would be a base metal Nitric acid didn't dissolve...
To find out, incinerate and HCL, AP, and see if there's anything left.
If so, try some HCL + bleach... doubtful but if gold, you'll find out..
If all that fials to dissolve it, then AR and test to find out...

Good Luck on making through to AR... would be nice...

B.S.

 

[kurtak]

I processed 90 g of electrical contact tips everything went good got 26 g of silver. I used nitric acid 50% and 50% water when the reaction was done I filter the solution and got a brown substance left behind any idea of what it could be.

Hi cheechQ

Its iron - you will notice that the contact point on the right of your pic has the silver point on top of a larger (round) base --- that larger round base is iron (or some alloy there of) When processing points you should always use a magnet to remove any that have iron (or nickel) in the mix --- I have had points that were on iron bus bars (instead of the more common brass or copper bus bars)

When processing points - keep the iron (&/or nickel) out --- another words process the non-magnetic separate from the magnetic

Sorry for the delayed response but I just recently re-joined the forum --- figured I would reply to this anyway to help others as well as you even though it late

Kurt