Study on purification of flaky graphite by argon arc plasma torch

Abstract

High purity graphite with purity above 99.9%, as an industrial raw material, plays an important role in the high-tech field. The existing physical and chemical methods of graphite purification technology has high cost serious damage to equipment and environment by acid and alkali, and complex processes. Thus the development of an excellent and effective graphite purification technology has become a research hotspot in recent years at home and abroad. A purification method of flaky graphite by arc plasma is established in this paper. The characteristics of high temperature which can be produced quickly by using arc plasma is used to treat the flaky graphite samples with a purity of 94.18% from Jixi City of Heilongjiang Province, under high temperature. The results show that the optimal discharge parameters are air flow rate 25 L/min, current 400 A and power 10 kW. At this point, the surface temperature of the arc plasma is up to 3350 ℃. Scanning electron microscope is used to compare the microstructure of graphite samples before and after arc processing to find the characteristics of shredding and breaking of graphite samples. The graphite purity and impurities are analysed according to national standard chemical analysis method of GB/T 3521 2008. After arc treatment, the purity of graphite is increased to 99.21%.