METHOD FOR CONCENTRATING USEFUL METALLIC MINERALS Russian patent published in 1999 - IPC

FIELD: concentration of native ore elements and native alloys of gold, silver, copper, metals of platinum group and other kinds of high-forgeability minerals. SUBSTANCE: method involves multiple-stage crushing, grinding and screening of rock into several products relatively homogeneous by size; grinding the largest fraction by impacts and concentrating by screening till concentrate of tough (forgeable) useful minerals is left on screening surface and friable minerals opened during impacting fall into undersize fraction. Grinding and screening operations with smaller fraction are conducted till fraction sizes of 0.08 or 0.074 mm are obtained. Method allows concentrates with content of useful component approximating 99% to be produced by enlarging forgeable particles. EFFECT: increased efficiency in producing concentrates with increased content of useful component, simplified ecologically clean method and reduced production cost.