Review of processing conditions for Murray Basin ilmenite concentrates

Australia is a major world producer of heavy minerals from mineral sand deposits, but to maintain its premier position in the world market place, the development of large resources such as in the Murray Basin will be necessary. There are two types of deposits in the Murray Basin, the finegrained (20-80 mu m) WIM-type deposits and those with coarser mineralisation (90-300 mu m), similar to other Australian deposits. Only the higher grade, coarse-grained deposits have been exploited, with little or no value realised from the majority ilmenite component because of its complex mineralogy. Compositional data for ilmenites from deposits across the basin are presented and potential processing options for them taking into account the grain size, composition and impurity element contamination are discussed. In particular, processes to lower chromia levels and fluidised bed and kiln-based processes to upgrade weathered ilmenites to suitable pigment feedstocks are discussed. Recommendations regarding further research required to enable commercial development of Murray Basin ilmenites are given.