Beneficiation of low grade Graphite from Khammam District , Andhra Pradesh

Abstract

A low grade graphite sample reported to be collected from K. G, Mines, Khammam District, Andhra Pradesh, was received from M/s. Indian Plumbago Co., Bombay for beneficiation studies so as to make it suitable for crucible making. The sample as received 19.7% F.C.,71.ash, 8.6% volatile matter and moisture, 1.7% S and 5.3% Fe in the ash. Quartz, feldspar, biotite and garn were the chief gangue minerals followed by pyrite and goethite. Flotation was employed with a feed containing 73% -200 mesh, using 0.12 Kg/ton Pine oil and 0. 5 Kg/ton of sodium silicate. The rougher concentrate (52. 0% -200 mesh) assayed 34.86% ash with a rejection of 83.5% of the total ash in the tailing. Two cleanings of the rougher concentrate after grinding it to 75% -200 mesh using additional quantity of 0. 03 Kg/ton of pine oil and 2.0 Kg/ton of sodium silicate yielded a final concentrate assaying, 77.8% F.C., 17.7% ash,0.42 % S, 4.5 % volatile matter and moisture. Due to very fine interlocking of siliceous gangue with graphite grains, it was not possible to produce a concentrate suitable for crucible making. However, this concentrate may be suitable for paint industries and foundries.