These have been some great suggestions, but let me add some furthur information. I'm an old man, a retired nuclear physicist, who is trying to suppplement his social security in order to survive by selling stuff in his garage. The quantity of material here is fairly large, about 30 pounds. At 75% and $29 per Ag ounce, it's max value is about $10k. I figure as dental fillings, it isn't worth much, but as purified (sterling?) it might be worth half the $10k. I had hoped I'd be able to remove the tin fairly easily, and then melt the silver into an ingot, but from the comments here, maybe it isn't so easy. I'm very limited in equipment, an oxy-acetylene welding torch, crucibles, simple chemicals. To me, the unique thing is that it is in the form of co-mingled powdered metals, not an alloy. A suggestion: Dentists stopped using silver for fillings several years ago, so there must be litterally tons of similar dental filling pellets to be had by an enterprising young chemist for essentially nothing. You may wonder, why does a physicist have old dental fillings? Silver absorbs thermal neutrons like a sponge, becoming gamma radioactive, and tin doesn't.
