Process for recovering valuable metals from a dust containing zinc

Abstract

There is disclosed a process for recovering valuable metals from a dust containing zinc comprising mixing the dust containing zinc with a reductant and a flux for regulating the basicity of slag, forming the mixture into pellets with a pelletizer, charging the pellets into a shaft type preheating-prereducing furnace provided with a preheating zone at the upper part and with a reducing zone at the lower part and removing, in the preheating zone, moisture and ignition loss components in the pellets, while prereducing in the reducing zone, the pellets under such conditions that a reduction of iron oxide is made to proceed selectively while the reduction of zinc oxide is suppressed to the possible minimum, charging the prereduced pellets into a melting furnace to melt and reduce them in the furnace, separating zinc, or zinc and lead, by evaporation followed by condensation to recover them, and separating iron and lead, or iron, according to the difference in their specific gravities to recover the iron as a molten pig iron and the lead as a crude lead.