| 摘要 |
1,182,455. Coking pitch. CHARBONNAGES DE FRANCE. 14 March, 1967 [14 March, 1966], No. 11944/67. Heading C5E. [Also in Division C1] Carbons produced by carbonization of pitches having a highly aromatic hydrocarbon content are hardened and their graphitizibility reduced by adding from 10 to 16% by weight of ammonium sulphate as a solid or in solution to the pitch before its carbonization. Suitable pitches are those obtained from the distillation of high temperature coal tars or cracking bitumens. In one example the mixture is carbonized at a speed of 1‹ C. per minute in a neutral atmosphere up to 550‹ C. and is then carbonized at a heating speed of 3‹ C. per minute up to 1000‹ C. and is maintained at that temperature for half an hour. The hard carbon product has high electrical resistivity and may be used as a reducing agent in electro-metallurgy, as a furnace heating element, as resistance granules in graphitization furnaces, and as raw material to prepare active carbon. |
