Optimisation of the baluba east ore treatment

Abstract

The Baluba east concentrator is part of the Roan Antelope Mining Corporation (RAMCO) which is a unit of the Binani Group of Companies. It treats an ore which is a mixture of sulphide and oxide copper minerals. In the flotation of mixed sulphide - oxide ores, the sulphide minerals are floated first, then followed by a sulphidisation step of the oxide minerals to effect their flotation. This test work was carried out because of a decrease in the grades and recoveries obtainable during the period of January 1998 up to around September 1998. This was so despite having an above average head grade of 1.91%Tcu. The optimum mesh of grind was found to be 65% passing 75 ìm using release analysis and theconclusions were drawn on the basis of flotation kinetics. The optimisation of reagents addition was done using a FACTORIAL DESIGN of experiments to improve the reliability of the result and Analysis of Variance(ANOVA) and the F-test were used to draw meaningful conclusions. Dosages of 120g/t collector (SIPX) and 100 g/t conditioner (NaHS) were obtained as the optimum reagent levels. The associated concentrate grade was 6.10%TCu (without a cleaning stage) at a recovery of 90.16%TCu. This adjustment in reagent consumption rates, if effected, would introduce a 10% reduction incollector consumption and a 50% reduction in conditioner consumption, which clearly indicates a significant reduction in the overall costs of reagents per tonne ore treated.