The prices aren't there at 6-7 lb any more since the gold price dropped but still, with all the fluff (plastic-metal) left from teardowns your better off selling them whole to one of our good buyers. Save a lot of time and energy.
Unless you have at least 10,000 lbs of phones then I don't think a smelter/refiner would work with you. It takes a lot to get their attention. Your just a bigger guppy in this big recycling ocean.
Bookmarks