Alpaca alloy dissolving

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razor1983

New member
Joined
Mar 28, 2020
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2
I find myself in a bit of a dead end. Perhaps if you have the time and will you'll try to help me.
I have a quantity of aprox. 60 kg of AgPd contacts and the support is made of alpaca alloy(Cu-Ni). I have been trying to dissolve the alpaca in H2SO4+ H2O2 solution but it works very hard and it uses a lot of H2SO4. For example for 1kg or 2.2 lbs I used roughly 8 litres or almost 2 gallons of acid. The contacts are aprox. 9-10% of the total mass.
Any ideas would be greatly appreciated.
 
instead of using sulfuric acid,one should go after the Ag and The PD using nitric acid--- then hcl or nacl to form agcl,filter the agcl out,and in the liquid you have PD----and in the rest of the alpaca,or perhaps allthe metals have gone to the solution as copper nitrate and niquel nitrate-----the pd can be withdrawn from the solution by your method----i use my method---regards---Arthur Kierski
 
Thank you for the advice. I have tried HCL +H2O2 but it also dissolves part of the Pd in the contacts and also it uses roughly the same amount of acid.
Mersi pt sugestie. Merge cu H2SO4 + PERoxid dar greu pt ca nichelul din aliaj face un strat de oxid f rezistent la acizi.
 
Dilute the acid with water in order to have more room for the salts of Cu and Ni to dissolve. This way you move much faster. Concentrated acid work very slow and the salt of metals needs room to dissolve.
 
Unless you're not able to obtain nitric I don't understand why you're using piranha on your alloy. Nickle, copper, silver and palladium will easily succumb to nitric. After dissolving in nitric I would then cement everything with copper. This way you'll have a fairly clean silver/palladium sponge after washing. Then dissolve the sponge in nitric again. Now you can use HCL to create silver chloride and separate it from the Pd liquor. Now you can process the silver and Pd on their own.
 
goldenchild said:
Unless you're not able to obtain nitric I don't understand why you're using piranha on your alloy. Nickle, copper, silver and palladium will easily succumb to nitric. After dissolving in nitric I would then cement everything with copper. This way you'll have a fairly clean silver/palladium sponge after washing. Then dissolve the sponge in nitric again. Now you can use HCL to create silver chloride and separate it from the Pd liquor. Now you can process the silver and Pd on their own.
Hey GC good to see you around.

Eric
 
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