Silver and Aluminum

praeclarum

Let's say I have a mixture of silver and aluminum metal, and I just want the silver metal. How do I just get the silver metal and get rid of the aluminum?

Also, if I have silver metal and I want to make silver nitrate, what molarity HNO3 should I add?

Borek

Small scale or industrial scale? Alloy or mixture of shaves/filings?

In general you can either try to dissolve both and precipitate one only, or dissolve only one and then filtrate whatever is left.

No clear idea about the molarity, I would go for a stock 68%.

MrSid

For a selective dissolution of aluminum leaving the silver, I might try using hot aqueous 10% NaOH. Raney nickel is made by using the NaOH reaction on an aluminum nickel alloy having at least 10% aluminum, leaving a porous nickel sponge that contains adsorbed hydrogen from the reaction of Al and NaOH (aq). The sponge is washed exhaustively with distilled water to remove the sodium aluminate and residual caustic and kept under water as it it is pyrophoric when dried. The silver analog probably won't contain the hydrogen to to make it a pyrophoric substance; a final treatment with weak HNO3 will displace more impurities, and a melting of the dross with a flux will probably be rewarded by purified silver bead...