Study On Preparation Of Isotropic Graphite With Nature Amorphous Graphite

To meet the rapidly increasing demand of high technology industry, the isotropic graphite, because of the excellent property, is widely used in a lot of industry, such as semiconductor, nuclear energy and spark machining. A mass of isotropic graphite is imported every year to satisfy the huge requirement, as the result of the lagging manufacturing technique of isotropic graphite contrasted with Europe, America and Japan. For this reason, the manufacturing technique which is suitable for China is studied in this article.Firstly, amorphous graphite, flake graphite, Second coke and refinery coke are studied as filler. Result shows that the material prepared from amorphous graphite by mould pressing has an isotropy ratio about1.10, which is reached the prerequisite of near-isotropic graphite, while much better than it of others.Secondly, a new method of mixing filler and binder is researched. The filler powers are surfaced by solution prepared from binder and organic solvent. The viscosity of system in this method is lower than the current one; therefore the filler and binder can be mix well.Finally, the technology of preparing isotropic graphite by amorphous graphite is studied. The result illustrates that graduation effect the bulk density of the isotropic graphite. High bulk density can be acquired in the condition that the filler with smell granularity fill the cavity of filler with large granularity. Impregnation can improve the bulk density and mechanical property of the isotropic graphite. And the proportion of filler and binder also has influence of the character. While the binder increase, the formability of filler is improved, however the porosity of the material is also increased. The graphitizing degree of the binder pitch is increasing while the temperature of heat treatment is raised. Otherwise the isotropy ratio of the isotropic graphite only depends on the filler and the method of forming.