Selective flotation of complex Sulphide ores of India

Results of systematic flotation studies undertaken in National Metallurgical Laboratory on some of the low grade ores of copper, pyrite -pyrrhotite and a complex copper-lead-zinc are briefly presented in this paper. The copper ores of Khetri, Kolihan and Ghatiwali had chalcopyrite as the copper mineral with varied amounts of pyrrhotite and pyrite as the sulphide gangue, Selective flotation studies under controlled pH, produced copper concentrates assaying 24.5 to 29.72% Cu with recoveries ranging from 81,7 to 93.8 %Cu. The Rakha copper ore contained chalcopyrite with chlorite and quartz as siliceous gangue. The copper Concentrate produced under optimum flotation conditions assayed 30.1% Cu with 90.13% Cu recovery. A molybdenum concentrate assaying 60% MoS2 and represents 68. 4% Mo recovery was produced from the bulk copper Molybdenum concentrate. The Sikkim ore was a complex fine-grained mixture of Pyrrhotite, Sphalerite, Galena, and Chalcopyrite in a siliceous gangue of Quartz and chlorite, and the ore Minerals were finely disseminated with considerable intergrowth. Copper, lead and zinc concentrate assaying 27.55 Cu,53.6% Pb, and 5l.213%Zn with 75% Cu, 60% Pb, and 76% Zn recoveries respectively were produced by selective flotation. Flotation concentrates analyzing 45.1 to 47, 3% S with 61 to 88.9% S recoveries were produced from two low-grade pyrite-pyrrhotite samples from Saladipura in Rajasthan.