USING A DIRECT-CURRENT ARC FURNACE TO RECOVER COBALT FROM SLAGS

Cobalt can be recovered from a variety of sings by treatment with a ca rbonaceous reducing agent in a direct-current arc furnace at around 1, 500 degrees C. The principal materials suitable for treatment using th is technology are primary smelter slags, which typically originate fro m the processing of sulfide concentrates. The technology has been test ed using copper, nickel-copper, and lead smelting slags. In all cases studied, cobalt is recovered as a valuable by-product to help improve overall plant profitability. Pilot-plant tests have demonstrated a cob alt recovery of more than 80 percent at power levels zip to 600 kW. Ve ry high recoveries of other valuable elements, such as nickel and copp er, have also been achieved.