Characterization of the UG2 Reef split-facies types, Eastern Bushveld Complex, South Africa: A mineralogical perspective

The Rustenburg Layered Suite of the Bushveld Complex has been extensively exploited for platinum group elements (PGEs), mainly from the Merensky and UG2 Reefs. An exploration drilling programme on the Booysendal Platinum producing Mine on the Eastern Limb of the Bushveld Complex revealed the occurrence of the UG2 Reef split-facies. In comparison to the normal UG2 reef (where the chromitite seam is not separated by pyroxenite), the split reef facies is defined by the splitting of the chromitite layers into multiple layers that are separated by pyroxenite middlings. This is anticipated to pose new challenges during metallurgical processing of the ore. To fully comprehend the mineralogical and metallurgical variations of the UG2 Reef split-facies types, geometallurgical test work was carried out on drill core samples collected from the mine. This was done to determine the bulk modal mineralogy, milling performance, mineral liberation and the flotation response of the various UG2 Reef split-facies types identified. Preliminary results of the study are presented and discussed in this paper.