High purity graphite is refers to the carbon content is more than 99. 99% which is high strength, high density, high purity, high chemical stability, compact structure, high temperature resistance and high conductive rate,also has a good wear resistance.
High purity graphite is widely used in metallurgy, chemical industry, aerospace, Electronics, Mechanics, Nuclear power industry etc.
Graphite purification method is mainly divided into two categories,one is the wet purification, including flotation, acid-alkali, hydrofluoric acid.The other is the fire purification method, including chlorination roasting method and high temperature method.In addition,with petroleum coke as raw materials to produce high grade fine particles of high purity graphite is also widely used.
The production process is:
Raw material→calcinations→crocus→ingredients→mix and knead→fine powder→molding→baking→dipping→graphitization.
Under the 2000~2800℃ high temperature, freon gases and chlorine gas are bubbled into it,to make impurity elements form chloride and fluoride volatile escape,when the temperature dropped to1800℃,pure nitrogen is bubbled into,and excess chlorine, fluorine gas discharged,to get the purpose of purification.
The fine structure and high purity graphite’s particle size is going to be smaller and smaller, particles of 5~l0μm structure of the graphite material has been industrialized production. Small pitch mesophase sphere as raw material to make the fine structure of high purity graphite which has been used.
When choosing purification methods, should consider the nature of the raw material, process characteristics and environmental factors.