Pressing of tin plate scrap - involves immersion in molten sodium followed by electrolysis avoiding waste water contamination

摘要

Tin plate scrap, e.g. from cans, is processed by immersion in molten Na at a temp. of 200-400 deg.C to combine the Sn with Na to form Na-Sn, soluble in the molten Na. Solid residues of steel and lacquer are removed and the molten Na, contg. Na-Sn is subjected to electrolysis at 300-590 deg.C as anode, with molten Na as cathode, the two being sepd. by a ceramic Na ion conductor, pref. beta Al oxide. ADVANTAGE - No contaminated wastewater is generated, Sn can be recovered in pure form.