The role of brannerite in the recovery of uranium from Witwatersrand reefs

The presence of significant amounts of brannerite in Witwatersrand mine products affects the extraction of uranium in that brannerite is not only more refractory than uraninite, but frequently occurs intimately associated with silicates or leucoxene and only occasionally as discrete grains. Examination of leach residues almost invariable shows uraninite in carbon (kerogen), and brannerite to be mainly responsibly for the residual uranium values. The mineralogical associations of brannerite are illustrated and clearly show that these associations inhibit recovery of the uranium in brannerite and thus are of economic significance