Sulfuric Acid Leaching Process for Producing High Purity Graphite from 92.6% C to 98% C

Hien Tran Thi, Nga Do Hong

Based on the characteristics of roasted graphite concentrate from Bao Ha, Lao Cai district, the present research a technology to increase the purity of the graphite carbon from 92.6% to 98%. Study was conducted on leaching agents, concentration of sulfuric acid, temperature, time, liquid/solid ratio affecting the process. The technological parameters chosen were: 10% concentration of sulfuric acid, reaction temperature room, reaction time 120 min, L/S=5. The results showed that the graphite content can be increased from 92.6% to 98%, which reaches the requirement for high purity graphite that used for manufacturing Mg-C breaks in steel mills.