To the editor:
Your recent article on recycled tin cans is inaccurate.Kennecott uses the recycled cans, which have been determined to be a source of quite pure, uniform iron. Kennecott waste dumps (not the ground) are leached with sulfuric acid, which removes the copper in the dumps as copper sulfate.
The iron cans are placed in a collector in a recovery plant, where 56 pounds of iron replaces 63 pounds of copper. The iron goes from elemental iron to iron sulfate solution, which is collected. The copper goes from copper sulfate to elemental copper, which goes to the refinery for recovery.
The use of these cans does, in fact, offer a productive recycling usage for a basic Utah industry.
Lawrence E. Thatcher
President, Thatcher Co.
Salt Lake City