Metals are recovered from ore concentrates by formation of a sulfide matte, grinding the matte, and leaching with h2so4 at high temperatures to selectively extract ni and fe. The residue is roasted and leached with dilute h2so4 to selectively extract cu. The residue contains a high concentration of pt, pd, and au. Thus, a sulfide matte was prepared containing cu, ni, CO, platinum-group metals, and au; ground to -200 mesh; leached for 4 h with 2.06M h2so4 at 95 deg-100 deg c; cooled and filtered. The residue containing cu 66, ni 1, fe 1 wt pct, pt 163, pd 360, and au 23 oz/ton, was roasted at 300 deg-415 deg c for 4 h, and leached for 5 h with 0.21M h2so4. Cu was extracted (98 pct) and the residue contained >98 pct of the precious metals.
U.S. Pat. 4,442,072, Apr. 10, 1984; Chem. Abstr. 99:91,695P