Preparation of high purity graphite by an alkaline roasting-leaching method

An alkaline roasting-leaching method was used to prepare high purity graphite from flake graphite from Hubei Jinchang instead of the commonly-used alkaline-acid method. The process parameters were optimized. Results showed that the fixed carbon mass fraction achieved by this method could be as high as 99.9% under the optimal conditions while that by the alkaline-acid method was only 85.8%, indicating that the alkaline roasting-leaching method was very effective to improve the fixed carbon content of the graphite.