Abstract:A wet alkali-acid preparation process was proposed for preparation of high-purity graphite. The effects of various factors on the preparation of high-purity graphite during pressure alkaline leaching and hydrochloric acid leaching for impurity removal were investigated. The results show that removal rate of aluminum and silicon is 88.18% and 89.69% respectively under the conditions including alkaline leaching temperature of 220 ℃, alkali concentration of 270 g/L, L/S of 8, time of 2 h, and stirring speed of 500 r/min. The fixed carbon content of high-purity graphite products is 99.89% above under the atmospheric acid leaching conditions including temperature of 80 ℃, acid concentration of 12%, time of 4 h, and L/S of 4. After sieving through a 200 mesh sieve, the residues on the sieve show an ash content of 0.092%, resulting in a fixed carbon content of 99.91% and a moisture content of 0.15%, which meet the technical requirements of medium high purity graphite LC(-)75-99.9 product of flake graphite (GB/T 3518—2008).