SULFURIC-ACID PRESSURE LEACHING OF CU-NI-CO MATTE OBTAINED FROM COPPER CONVERTER SLAG - OPTIMIZATION THROUGH FACTORIAL DESIGN

Cu-Ni-Co matte obtained by pyritic smelting of copper converter slag was leached at elevated pressures. The leaching studies were carried out using a factorial design for optimisation. Regression equations for the extraction of copper, nickel and cobalt were determined from a 2(3) full factorial design, taking temperature, oxygen partial pressure and acid concentration as the variables. The regression equations (except for cobalt extraction at two hours) satisfactorily predicted the extractions for another 2(3) full factorial matrix chosen with narrow intervals of the three leaching variables.