Platinum group elements (PGE) are recovered by flotation from the Merensky reef in the Bushveld Complex, South Africa. The reef contains approximately 1% sulphide minerals in the form of chalcopyrite, pentlandite and pyrrhotite. The PGEs are strongly associated with these sulphide minerals. Different reagent combinations are used in the flotation process to extract the valuable minerals from the reef. Batch flotation tests were conducted on a typical ore from the Merensky reef to investigate the role of dithiophosphate (DTP) and copper sulphate (CuSO4) addition on the flotation response of the ore using both guar and caboxymethyl cellulose (CMC) type polymeric depressants. Differences in the flotation response of the individual minerals present in the ore to the different reagent combinations were observed. These differences and the reasons for the differences are discussed. (C) 2005 Elsevier Ltd. All rights reserved.