Journal of the Southern African Institute of Mining and Metallurgy
versão On-line ISSN 2411-9717
NTENGWE, F. e WITIKA, L.K.. Optimization of the operating density and particle size distribution of the cyclone overflow to enhance the recovery of the flotation of copper sulphide and oxide minerals. J. S. Afr. Inst. Min. Metall. [online]. 2011, vol.111, n.4, pp. 295-300. ISSN 2411-9717.
The Konkola Mine, a subsidiary of the Konkola Copper Mines Plc (KCM) which is owned by the Vedanta group of companies of India and Zambia Consolidated Copper Mines Holding limited, is located at Chililabombwe in the northern extension of Zambia's Copperbelt province. In its operations, the mine has been experiencing problems in ascertaining the optimum degree of fineness and the operating density of the hydrocyclone overflow in order to achieve high flotation performance. It was believed that recovery of sulphide copper minerals from Konkola ore is a function of the fineness of the grind so that it might be an economical justification to modify the grinding plant in order to run at lower cyclone overflow densities than the case is now. In an effort to improve these operations, it was decided to carry out test work on various hydrocyclones of sizes 0.381 m, 0.4575 m and on 0.508 m. The later was found to give satisfactory results and was installed on the plant. Despite giving satisfactory results there was need to investigate further to establish the working densities and size. Increasing the density of cyclone overflow decreases the per cent passing 75 ym at least in the range 1 080-1 150 g/l. Furthermore, hydrocyclones give better separation at low densities of feed and hence the efficiency is high at low feed densities. Circulating load increases with an increase in feed densities and an decrease in the grind. The flotation performance in both sulphide and oxide copper minerals rougher stages is enhanced with an increase in the degree of fineness of the grind, with an optimum being obtained at a density of 1 150 g/l and 81.4% passing 75 ym.
Palavras-chave : Konkola mine; hydrocylone; optimum degree of fineness; sulphide copper minerals.