Mickey, there is a guy on castboolits that will trade lb for lb zinc contaminated lead for straight lead. He makes cannonballs or some such. I always sort through my wheel weights first separating steel and zinc from lead. Also if you keep the heat down the zinc's will float.
After I get through sorting the zinc out of seven five gallon buckets I'll give him the zinc if he wants it or anybody else that can use it. I may see what a scrap dealer will give me if nobody wants it.
