GB842248A - Improvements in metallurgy of zinc - Google Patents

Abstract

Zinc metal is produced from impure source materials containing halide and oxide contamination by treating the comminuted material with a basic material selected from lime, calcium carbonate, magnesia, dolomite and mixtures thereof to convert the halides in the starting materials to oxides and to form the corresponding halide of the basic material, introducing the reaction product into a molten bath of at least one alkaline earth metal halide, contacting the melt with a mixture of solid and gaseous carbonaceous reducing agents to reduce zinc oxide to zinc and recovering metallic zinc from the vapours evolved. The solid reducing agent, which may be coal, coke, petroleum coke or lampblack, and the gaseous reducing agent, which may be hydrocarbon, such as natural gas, or producer gas, are preferably used in amounts not over 50% in excess of the amounts theoretically necessary. The zinc containing material and the base may be reacted by ball milling them together and the solid reducing agent may be included in the mixture. The reaction product may be charged directly into the salt bath or the halides present may be dissolved out and the residue added to the salt bath after drying. Specification 829,899 is referred to.