Halidation of manganiferous ore to obtain metal values and recovery and

Abstract

This invention provides a halidation process for obtaining a high purity manganese oxide from a manganiferous ore, while reclaiming a substantial portion of the hydrogen halide reagent. The process comprises halidating the ore with a hydrogen halide and leaching to form the corresponding halogen and an aqueous solution comprising dissolved manganese halide and ferric halide. The hydrogen halide can be in the gaseous state and/or dissolved in the aqueous leach solution. The manganese halide and the ferric halide are preferably individually separated from the leach solution by crystallization and by selective extraction, respectively. The crystallized manganese halide is reacted with water at a temperature of from about 400.degree. C to about 700.degree. C to yield the corresponding hydrogen halide, which is recycled, and manganese oxide. In one embodiment, a concentrated leach solution is formed at a temperature of at least about 90.degree. C using at least some gaseous hydrogen halide as the reagent, the solution having a concentration of manganese halide greater than the saturation concentration at ambient temperaures. The solution is then cooled to ambient and the manganese halide crystallized out. The ferric halide is then extracted from the solution. In a second embodiment, the ferric halide is first extracted from the leach solution and the manganese halide is then crystallized by evaporating the gaseous solution. If other nonferrous metal values are present, these can be removed by precipitation or cementation. Any remaining aqueous liquid is preferably recycled.