Patent ID: 8088192

Claim:
A process for recovering non-ferrous metals from metallurgical residues containing these non-ferrous metals at an oxidation state of greater than or equal to zero, in an alternating current type plasma arc electric furnace comprising a plurality of electrodes, containing a liquid copper heel, covered by a fluid slag, said process comprising at least one fusion-reduction phase A, comprising the following steps: A1 charging metallurgical residues comprising non-ferrous metals onto the heel contained in the plasma arc electric furnace, A2 fusion of the metallurgical residues in the fluid slag at a slag/copper bath interface, A3 reduction of at least the non-ferrous metals to oxidation state zero, and A4 intense stirring of the liquid copper heel by injection of inert gas so as to avoid crust formation and to accelerate the reduction reaction and to cause copper-miscible non-ferrous metals to pass into the copper heel.