Formation of Isotropic Coke Microstructure. 3. Generation of Isotropic Coke from Thermal Oxidation Products of Coal Tar

The thermal oxidation of coal tar and coking products of oxidized pitch is investigated. An isothermal process of thermal oxidation is considered, as well as a process with steady increase in the temperature. The oxidized pitch is subjected to technical analysis (determining the fractional composition, the softening temperature Tso, and the yield of volatiles), elemental analysis, and thermal analysis. The pitch is carbonized in standard conditions; the degree of swelling is determined on heating. The coke produced is optically analyzed. After treatment at 900–1600°C, the porous structure of the quenched coke is studied. The results confirm that isotropic coke may be obtained from coal tar; optimal production conditions are determined. The isotropic coke obtained has a highly uniform microstructure and is resistant to cracking at high temperatures.