Sulfidisation process and apparatus for enhanced recovery of oxidised and surface oxidised base and precious metal minerals

摘要

A method of treating value bearing material comprising oxidized or surface oxidized mineral values includes the steps of crushing the value bearing material, contacting the crushed material! with a sulfide solution to sulfide the oxidized or surface oxidized mineral values, and adding ions of a selected base metal to the crushed value bearing material. The value bearing material may comprise oxidized or surface oxidized base metal or precious metal minerals. The crushed value bearing material is prepared as a slurry or pulp comprising from 15% to 40% solids and the remainder comprising water. The sulfide solution preferably comprises a soluble sulfidiser such as sodium hydrosulfide and the base-metal ion solution preferably comprises metal salt of base metals like copper or iron. In a preferred embodiment of the method, the sulfide ion concentration in the slurry is measured with an ion-specific probe which measures the sulfide ion concentration as a potential, and the quantity of sulfidiser solution in the slurry is adjusted to maintain the measured sulfide ion concentration at or near the predetermined value. The invention extends to an installation for treating value bearing material according to the method.