SULFER RECOVERY FROM THE LEACHED RESIDUE PRODUCED IN THE DIRECT LEACHING OF ZINC CONCENTRATES

摘要

A solid sulfur is more useful to recover and store than a sulfuric acid as a by-product in the zinc hydrometallurgy. In this experiment a zinc concentrate (sphalerite) was leached with ferric sulfate at about 373 K for 3 to 6 hours. Zinc was leached more than 95%. After a solid-liquid separation, the leached residue contained solid sulfur was obtained. The particles in the residue were dispersed by lignin and the solid sulfur of approximately 85% was recovered as float product by a flotation with frother in the pH 4. The dried float product was heated at 413K for 2 hours. The pure solid sulfur was recovered. On the other hand in the leached liquid a zinc oxide was added and ferrous iron was oxidized to ferric iron by blowing oxygen. This ferric iron was returned to the zinc leached process after solid-liquid separation.