Carbochlorination of Cobalt Oxide and Electrochemical Recovery of Co in an Amide-Type Ionic Liquid

摘要

Recycle of rare metals from electric devices is demanded from the viewpoints of production costs and environmental protection. Carbochlorination is a traditional pyrometallurgical process to convert metal oxides in metal waste into metal chlorides. However, high temperature is often required for the carbochlorination process, leading to an increase in the recycling cost. We have already reported that the dissolution of palladium oxide was possible in an amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) containing BMPCl by carbochlorination at a relatively lower temperature. In the present study, the carbochlorination of cobalt oxide (CoO) was investigated in BMPTFSA containing BMPCl. Recovery of Co was also attempted by electrochemical reduction of the cobalt species in the ionic liquid.