First determine the solid-liquid ratio, followed by the gradual reduction in the amount of hydrofluoric acid, and then reduce the amount of hydrochloric acid, nitric acid. The ratio of hydrochloric acid and nitric acid was set at 3: 1, the formation of weak aqua regia, and because of hydrofluoric acid, hydrochloric acid, nitric acid strong combination, the final process freeze in 99% spherical graphite powder, purified to 99.95 ~ 99.96%, with acid cost of 1058 yuan; ≥ 95% of the -100 mesh graphite powder after crushing and spherical, purification purity is also stable at 99.95 ~ 99.96%, after the stereotypes of the process cost per ton of acid savings of more than 1,000 yuan, and waste acid wastewater treatment is also a lot easier.

Hydrofluoric acid method of high purity graphite purification process, after the production of large-scale refining plant, with a large output, high purity, stable performance, reliable quality, and the applicability of production equipment, production operation is simple, completely out of the purity of graphite is high, the greater the amount of acid used, the higher the acid concentration of the cycle, for the graphite chemical purification industry trip out of the new method.