High Purity Graphite Powder
high purity graphite powder is a highly purified form of natural, inorganic carbon. It has a variety of physical, chemical and thermal properties that make it an ideal material for many technological applications.
Several methods can be used to purify graphite, including hydrofluoric acid leaching, chlorination roasting and alkali treatment. These methods have their own advantages and disadvantages. The alkali method has low production costs and low requirements for production conditions, but it is very difficult to achieve a fixed carbon content of 99.9%, and the chlorine gas used in this process is very toxic and corrosive.
The chlorination roasting method has a better fixed carbon content, but it requires strict safety protection measures and production conditions. The chlorine gas is poisonous and corrosive, and it must be treated with special equipment and properly sealed.
Another alternative is a new processing technique which utilizes a high purity raw needle coke such as petroleum derived needle coke, to create a highly isotropic green graphite. The green article is then mixed with binder pitch, milled into a molding powder and isostatically molded to create a large block of high-purity graphite.
A further method of reducing impurities in the green graphite is to electrochemically exfoliate the flake graphite with an aqueous acid solution. The resulting sheets have an excellent morphology similar to graphene. They are suitable for electrochemically expanding and can be utilized in a wide range of industrial applications. Unlike traditional methods, this process does not use chromic acid and can be scalable.
