Isotropic and high density carbon made from carbonaceous powder prepared by distillation under reduced pressure

It is attempted to produce high density, high strength and isotropic carbon made from carbonaceous powder. The carbonaceous powder was prepared by carbonization of coal-tar pitch at a temperature of 440 - 5000C and subsequent distillation under reduced pressure. The distillation was performed at a temperature of 300 - 5000C below the carbonization temperature. In some cases additional quinoline extraction was carried out on the powder. Green carbon body was formed without binder pitch under isostatic pressure at room temperature. The body was heat-treated at a temperature of 1100 - 28000C. Bulk density, weight loss, shrinkage, strength, lattice parameter, crystallite size and BAF of the obtained carbon body were measured. It is confirmed that high density, high strength and isotropic carbon made from the carbonaceous powder and the following results were obtained. 1) BS (benzene soluble) fraction, β-resin (benzene insoluble and quinoline soluble) fraction and QI (quinoline insoluble) fraction were able to fractionate by distillation under reduced pressure. Concentration gradient of each fraction seems to exist in the carbonaceous powder. 2) Using the powder prepared by a lower temperature of the carbonization and/or the distillation, the carbon body had higher bulk density and higher strength. 3) The β-resin fraction had the effects of increasing the green density and enhancing the shrinkage of carbon body during the heat treatment. (author)