Beneficiation studies on a low-grade copper ore from Dhukonda block, Agnigundala area, Andhra Pradesh.

Abstract

A Sample of low-grade copper ore from Dhukonda block, Agnigundala area, Guntur Dt., Andhra Pradesh, assaying 1.24% Cu, 68.23% SiO2, 1.23% S, 2.7% Fe, and 3.87% MgO was subjected to intensive beneficiation studies in NML with a view to determining optimum conditions for production of a copper concentrates suitable for smelting. The chief copper-bearing mineral in the sample was chalcopyrite, while quartz, dolomite, and feldspar constituted the gangue. Other accessory Cu minerals present in the sample in minor amounts were bornite, chalcocite, and native copper. The copper minerals were fairly well liberated from gangue at about 100 mesh size. Tabling as well as flotation methods were investigated of the sample at -65 mesh size produced a concentrate assaying 20.1% Cu but with a recovery of 45.9% Cu only. Optimum conditions for flotation of copper minerals were established by varying the fineness of the feed, the collector and frother additions and pH. Flotation employing a feed containing 51.3% -200 mesh and potassium ethyl xanthate and pine oil, at a pH of 7.4, yielded a rougher concentrate assaying 17.88% Cu with a recovery of 93.7% Cu in it. One cleaning of the rougher Cu concentrate produced a refloat concentrate was of a grade of 29.4% Cu but with a slightly lower recovery viz., 88.6% Cu could also be produced by subjecting the rougher Cu float to two cleanings. The above response of the ore is considered sufficient to warrant sponsoring of further detailed investigations to evolve a flowsheet with improved recoveries, from representative ROM samples. Attention is also invited to the Pt, Co, and Ag concentrations in the flotation concentrates.