Abstract: A method of leaching zinc from a zinc concentrate comprising leaching a zinc concentrate in an aqueous solution containing free sulfuric acid and ferric ions, whereby elemental sulfur is deposited on the zinc concentrate, and grinding the zinc concentrate under atmospheric pressure in the aqueous solution to provide particles of the zinc concentrate having surfaces, wherein the elemental sulfur and other by-products which form on the surfaces of the particles of the zinc concentrate are stripped by the grinding.

Abstract: An apparatus for leaching zinc concentrates which comprises: a pressure vessel for charging therein a solution containing at least free sulfuric acid and iron ions, a stirrer which is disposed in the pressure vessel, an oxygen gas supply pipe that extends into the pressure vessel from the outside of the pressure vessel, the oxygen gas supply pipe having an oxygen gas inlet port which opens below the stirrer, and a discharge pipe through which an iron-containing, acidic solution or a slurry that results from the reaction of said solution containing at least free sulfuric acid and iron ions is discharged to the outside of the pressure vessel, the discharge pipe having a drain port which is open in a lower part of said pressure vessel.

Abstract: In one method, a zinc concentrate is leached as elemental sulfur and other by-products are stripped from the surfaces of the particles in the concentrate by means of a grinding machine such as a ball mill. The ferric ion consumed by leaching is regenerated for recycled use by introducing oxygen into the post-leaching solution flowing through feed pipes. This method can shorten the leach time by a substantial degree.