Uraninite and masuyite are the major uranium minerals, essentially fine grained, in the ores studied. Over 40% of the uranium is distributed in the -8µm fractions compared with copper, which is concentrated mainly in the +8-20µm range. Uranium is concentrated mainly in the copper ore zones, with only marginal levels in the gold-only ores. Poor liberation (due to association with copper sulphides) and entrainment are the major factors identified, which should contribute to uranium recovery in the concentrate.  In this study, approximately 60% of the total uranium was recovered due to association with copper sulphides whilst 40% was via entrainment. Minimizing entrainment of liberated fine uranium particles is crucial to reduce concentrate  uranium grade. Strategies such as effective froth washing and careful consideration of flotation cell hydrodynamics would be required to optimize fine U rejection.

Petrographic examinations of  the ore had indicated  the  impracticability  of  attempting  to concentrate the uranium by floating individual grains of  uraninite. Liberation  of  the  uraninite required grinding to  sizes below  those  suitable for  flotation. However,  there  was  preferential  association  of  the uraninite  with  some  minerals while  others were free of  uraninite  attachment. The  approach to  the development  of  a flotation process was,  therefore, based  upon  an attempt to  concentrate the uraninite by  floating  carrier  minerals. The  following  paragraphs discuss  the various stages of  the process with regard to the factors tested and the conditions under which best  results  were obtained.