The first thing you should do before selling old tire rims for scrap is to make sure they can no longer be used. Unless a rim is severely dented or bent, someone might be willing to buy them for a price that is usually higher than scrap metal. If the rims are at the point where they should be scrapped, all you can really do is call around and try to get the best price you can for scrap metal.
Determine what metal was used to make your rims. As a general rule, white metal is either zinc, tin, lead, aluminium or magnesium. White and silver metal is usually white cast iron. If you are not sure what metal it is, take a rim to a recycling centre or junk dealer. They should be able to tell you.
Contact local recycling centres and ask what they pay for scrap metal. You can get a general idea of what scrap metal is currently selling for by looking at websites on the Internet, but keep in mind the money a recycling centre is willing to pay can vary.
Contact local junkyards or junk dealers and ask what they will pay for tire rims. A junk dealer is the go-between you and a recycling centre. A junk dealer will often buy your rims in order to sell them for scrap metal.
Place an ad on the Internet offering scrap rims for sale. Obviously, this is probably only worth it if you have a large number of rims to offer.
Contact a local business such as a used tire establishment and offer them your scrap rims for a small price. It may take the rims off your hands because it deals with a junkyard or a recycling centre on a mass basis. If you offer to buy something off them, they might be even more accommodating.