Cobalt recovery from Metallurgical Wastes of Zinc Industry

Abstract

Cobalt is a metal of great strategic importance for super alloys which are used in aerospace. Cobalt is also extensively used in the manufacture of cemented carbide tools , magnetic alloys and even in ceramics as a colouring agent. During the hydro-metallurgical processfor extraction of zinc, valuable metals can also be recovered as by-products from the waste materials. Under the `Home Grown Technology Programme ' of TIFAC, a flow sheet has been developed and process optimised for cobalt recovery from metalli rgical wastes from the zinc industry. The work was done jointly by HZL & BARC and has not only resulted in increased yield of cobalt to mop e than 60% but also improved the product quality to achieve 99.8% pure cobalt. This paper briefly outlines the modified process flowsheet consisting of washing, roasting, three stage leaching , oxalate precipitation and solvent extraction. Results of the market survey for cobalt metal and powder carried out as a part of the study are also enclosed.