Recovery of flake graphite from kish

A laboratory investigation was made to recover high quality flake graphite from the steel making waste. The waste, which is called Kish, initially contained 65% graphitic carbon. Acid leaching technique was employed to purify the waste and it was completed in two steps using HCI and HF. This paper dears with the results on the optimization of leaching parameters like acid cohcentration, liquid to solid ratio, time and temperature. First leaching with HCl upgraded the Kish to 92.48% @99. 74% recovery, while second leaching with HF further improved the grade up to 99.38%@ recovery 99.89%. (author)