Flotation studies on a Copper ore sample from Ghatiwalli Adit Khetri, Rajasthan received from National Mineral Development Corporation Ltd.

Abstract

Laboratory studies have been conducted on the flotation of a low-grade copper ore sample from Ghatiwalli Adit Khetri, Rajasthan received from the National Mineral Development Corporation Ltd. The sample assaying 0.99% Cu, 23.1% Fe, 6.08% S, 42.38% SiO2, 11.4% Al2O3, 5.96% MgO, 0.14 dwt/T Au and 2.26dwt/T Ag consisted of pyrrhotite, magnetite, chalcopyrite and pyrites opaque minerals in order of abundance and traces of chalcocite. The ore was chiefly composed of siliceous gangue. Chalcopyrite was mostly freed below 150 mesh. Optimum conditions were determined for effecting maximum recovery of copper, using 0.1ib/T of potassium ethyl xanthate as collector and 0.074 lb/T of pine oil as frother during roughing at pH 7.6. Rougher flotation at natural pH (7.6) followed by three cleanings of the bulk rougher concentrates at 9.5 pH yielded a cleaner concentrates assaying 20.46% Cu, 33.3% Fe, 30.1% S, 2.0 dwt/T Au and 23.6 dwt/T Ag with a recovery of 82% Cu. The grade of concentrate improved to 29.72% Cu, 31.1% Fe, 33.4% S, 2.2dwt/T Au and 27.8% dwt/T Ag with a recovery of 80.2% Cu by grinding the bulk rougher concentrates to -200 mesh before cleaning at 9.5 pH. The recovery is expected to improve in actual plant practice where middlings are recirculated.