Beneficiation of Graphite from M/s. National Carbon Co. Calcutta

A Sample of graphite received from M/s. National Carbon Co., Calcutta assayed 77.85% Fixed Carbon, 17.6% Ash, and traces of Copper. Quartz was the chief gangue followed by minor amounts of Pyrite and hematite. Liberation of gangue from graphite was not complete even at -200 mesh. Optimum conditions such as grind, collector quantity, pH etc. were determined and bust results were obtained when a combination of pine oil and light diesel oil was employed for roughing. The rougher float assayed 85.33% Fixed Carbon and 10.46% Ash with a recovery of 99.4% Fixed Carbon. Three cleanings of the rougher float yielded a refloat concentrate assaying 89.0% Fixed Carbon,7.1% Ash, 3.9% volatile matter +Moisture, 0.22% and 7.89% Fe in the Ash with a recovery of 97.3% Fixed Carbon in it. Regrinding of the rougher float to 80.0% -200 mesh followed by refection yielded a refloat concentrate assaying 90.0% Fixed Carbon,6.4% Ash ,3.6% Volatile matter + Moisture and 0.21% S (9.1% Fe in the Ash) with a recovery of 99.0% Fixed Carbon in it. The F.C., Fe and contents being within the specified limits, the concentrate may be suitable for use in dry battery manufacture.