Direct reduction of copper-iron-silicon oxide melts

摘要

The selective reduction smelting of Cu_2O in Cu_2O-FeO_x-SiO_2 melts has been studied at laboratory level, using as a feed a dead roasted calcine from a copper concentrate. The purpose of the study was to evaluate the kinetic and mechanisms of the indirect reduction with Co and the direct reduction with graphite from 1260deg C to 1350 deg C. The reduction rate by CO was found to be 10~(-2) to 10~(-1) mole Cu_2O m~(-2)S~(-1). The graphite reduction macrokinetics for FeO and Fe_2O_3 containing melts, was found to be a first order reaction with respect to the Cu_2O concentration, with a kinetic constant of 10~(-4) to 10~(-3) s~(-1). The reduction rate was not sensitive to temperature nor to stirring, in the range studied. The measured reduction rate is almost one order of magnitude larger than the observed rate for the direct reduction of FeO.