Mineral intricacies of the Namakwa Sands mineral resource

摘要

The Cainozoic Namakwa Sands palaeo-placer deposit is estimated to host more than 100 Mt of total heavy minerals of which the valuable minerals ilmenite, leucoxene, rutile and zircon constitute approximately 51% by mass. Almandine garnet and mainly augitic pyroxene dominate the diverse gangue mineral assemblage accessorized with kyanite, monazite, collophane, magnetite, haematite, chromite, corundum, cassiterite, hornblende, marcasite, Ce-florencite, baddeyellite, rhodonite, tourmaline, staurolite, spinel and titanite. The valuable mineral fraction conspicuously exhibits heterogeneous and complex characteristics, clearly reflected by distinct differences in major element chemistry and striking trace element signatures. LA-ICP-MS have proved particularly useful in discriminating several zircon and rutile colour varieties. The challenge for Namakwa Sands remains the optimal extraction of all valuable minerals irrespective of their chemical heterogeneity and related processing response.