Flotation studies on a low-grade copper ore sample from Nallakonda block, Agnigundala area, Guntur Dt., Andhra Pradesh

Beneficiation studies were carried out on a low-grade copper ore from the Nallakonda block, Agnigundala area, Andhra Pradesh assaying 0.92% Cu, 0.65% S, 2.78% Fe, 72.44% SiO2, 3.36% Al2O3, 3.54% MgO, 0.07% Co and 16.0 gms Ag/tone of ore. It was a lean copper ore containing minor amounts of chalcopyrite and bornite. Quartz was the principal gangue mineral with minor amounts of feldspar, carbonates, and micas The copper minerals were liberated from the gangue at about 100 size. Optimum conditions were determined for effecting maximum recovery of copper using 0.05 Kg/tonne of potassium ethyl xanthate as collector and 0.034 Kg/tonne of pine oil as frother during roughing at a natural pH of 8.6. Flotation employing a feed of 56% -200 mesh yielded a rougher float assaying 21.3% Cu with a recovery of 94.0%. With a copper recovery of 88.9%. The concentrate also contained silver as a valuable by-product.