Abstract: Metal values in non-ferrous metallugical slag are recovered by gently agitating the slag in contact with matte using stirring energy dissipation rates insufficient to emulsify slag in matte. These low agitation rates conserve energy by reducing cooling of the charge, especially by reducing the period required for the slag and matte to separate out into distinct layers after agitation, and the preferred energy dissipation rates increase the efficiency of the value metal recovery and avoid or reduce impairment of the reducing capabilities of the matte and hence its capabilities for reducing and collecting oxidized value metal species from the matte by avoiding or reducing oxidation of the matte as a result of dispersal of the oxidation-protective overlay of slag and contact of the matte with the ambient oxidizing atmosphere.