We have been very happy with Precious Metals West in Los Angeles
California....they can refine your scrap and return it to you in
product (they produce an amazing array of casting grain, solder,
sheet..etc) or place it on Tare for future purchases or send a check
for the value.
Besides being absolutely trustworthy, they are not as particular
about the seperation and cleanliness of the scrap. Some refiners
won't touch it if all scrap isn't same karat and clean.
In addition their return rate is very competitve.
I don't have their web address handy but they do have a web site.
They also sponsor the Kraftwerks conference that this year feature
Pedro Boregaard, Erica Courtney, Paula Crevoshay and others.
Other wise they can be found in the JA directory or the Los Angeles
listing . Let me know if you have trouble reaching them....I'll
unearth my rolodex.