Abstract: A platinum-palladium mine is located in Zimbabwe′s Great Dyke. In order to master the ore properties and promote the development and utilization of the resource,process mineralogy study was carried out systematically through chemical analysis,optical microscopy,scanning electron microscopy and automated mineral identification & characterization system, etc. The mineral composition,the occurrence state of platinum and palladium minerals,the distribution characteristics and the liberation characteristics of sulfide minerals were found out. The results showed that the grade of platinum and palladium in the ore are 1. 69 g / t and 1. 41 g / t,respectively. The main metallic minerals in the ore are pyrrhotite,nickelpyrite and chalcopyrite, the non-metallic minerals are enstatite and talc,and the platinum group minerals are mainly merenskyite, biteplatinite and braggite. The distribution characteristics of platinum and palladium minerals are quite complicated,and 83. 35% of platinum and palladium minerals are closely related to sulfide minerals. The particle size distribution of platinum and palladium minerals are mainly in the range of 1~ 20 μm,with the distribution rates of 91. 99% and 94. 68%. The particle size distribution of sulfide minerals is relatively uniform,with the distribution rate of +20 μm reaching 90. 65%. The distribution rate of monomer and rich intergrowth sulfide minerals in the ore reach up to 93. 84% under a grinding finessness of 85% passing 74 μm. Considering that platinum and palladium minerals in the ore have a close relationship with sulfide minerals,the sulfide minerals have a coarse dissemination size,and the ore contains a certain amount of talc and chlorite,meanwhile,platinum and palladium minerals are still embedded in the cracks and grains of gangue minerals to a certain extent,it is recommended to choose the principle process flowsheet of two-stage grinding flotation and flotation tailings gravity separation. The principle have much more advantages in reducing bad effect on flotation and improving the recovery of platinum and palladium minerals.

Key words: platinum-palladium ore,occurrence state,dissemination characteristic,particle size distribution