Quantifying the influence of classification with the 3 product cyclone on liberation and recovery of PGMs in UG2 ore

The UG2 ore in South Africa is exploited for its enrichment in the platinum group minerals (PGMs). Given that the PGMs are typically very fine grained, the potential for poor liberation is high, especially with conventional cyclones providing a poor split of the coarse silicates and fine chromites to the over and underflows, respectively. The 3 product cyclone has been developed as a potential solution to these problems by reducing the circulating load of chromite and providing a more liberated feed to the flotation circuit. Automated mineralogical analyses have been used to compare the differences in samples sourced from a conventional and a 3 product cyclone circuit and show that use of the latter, provides a better quality flotation feed with less coarse silicate particles, less PGMs locked in silicates and more liberated PGMs. This suggests that improving classification provides an additional means to better the theoretical grade recovery curve of the valuable mineral.