Flotation studies on low grade graphite ore from eastern India

A low grade graphite ore from eastern India was beneficiated by flotation to improve its quality. The ore was composed of 87.80% ash and 8.59% fixed carbon. Primary coarse wet grinding (d80: 186 μm) followed by rougher flotation in Denver flotation cell using diesel as collector and pine oil as frother yielded a rougher concentrate. Regrinding (d80: 144 μm) of this rougher concentrate was opted for further liberation of graphite. It was followed by cleaning in laboratory flotation column. This combined process of relatively coarse primary grinding followed by regrinding and cleaning in flotation column resulted in final concentrate of 7.44% yield with 89.65% fixed carbon and 6.00% ash. This approach of two-stage grinding to recover the flake graphite at the coarsest possible grind can help to minimize grinding energy costs. A conceptual flow sheet which is cost effective was developed based on this methodology.