Abstract: The alkali-acid methods is the major process in purifying amorphous graphite.Purification experiments on dosage of NaOH,roasting time,roasting temperature and dosage of HCl are conducted to find reasonable technological parameters for a graphite with fixed canbon content of 85%,particle size from 0.048 to 0 mm and impurities of SiO₂,Al₂O₃,Fe₂O₃ etc.in Hunan province.The results show that it is benefit to increase the fixed carbon content by properly increasing dosage of NaOH,roasting time,roasting temperature and dosage of HCl.Purified product with fixed carbon content of 98.79% is obtained at the conditions of mass ratio 0.6 of NaOH to the sample,roasting temperature at 600 ℃ for 60 min and the mass ratio of HCl to sample 0.4 mL/g.

Key words: Amorphous graphite, Fixed carbon, Alkali-acid methods, NaOH, HCl