Production of Carbon Solids from Coke covered with Mesophase

Abstract

It is attempted to produce carbon solids from coke powder covered with mesophase without binder pitch. The coke powders used were a calcined coke and a green coke (not calcined), and the pitches were a coal-tar pitch and the petroleum heavy oils. A mixture of coke powder of 5 or 10 wt% and pitch was heat-treated at 430°C for a certain period. The mesophase in the heat-treated pitch exists on the surface of the coke powder and this coke covered with the mesophase was separated from the heat-treated pitch by quinoline treatment as quinoline insoluble part. Carbon solids were prepared by carbonization of the molding made of quinoline insoluble part (QI) and measured these physical properties.The obtained results are as follows;1) Compressive strength of the carbon solids increased with increasing the mesophase content in QI. When the mesophase content in QI was 50 wt%, the compressive strength was 600-1300 kg/cm2 at HTT 1000°C and 300-500 kg/cm2 at 2800°C.2) The carbon solids made of the green coke covered with the mesophase from coal-tar pitch had the highest strength and bulk density. Also, high strength carbon solids could be obtained from the coke much covered with the mesophase from petroleum heavy oils.3) The values of the electric resistance and the coefficient of thermal expansion were comparable to those of carbon solids prepared from coke and binder pitch, and were varied with the mesophase content in QI.From these results, it is confirmed that high strength carbon solids are prepared from the coke powder covered with mesophase.