No abstract

The influence of the production conditions on the properties of coke is considered. Coke is pro duced in a pilot plant at the Institute of Technical Chemistry, Ural Branch, Russian Academy of Sciences, in a 200 L reactor equipped with an air supply valve and heating elements. The first stage in coke production is air blowing of the batch with constant temperature rise at 10-12°C/h from 290-310°C; the air flow rate is 45-55 L/kg h. At this stage, the final air blowing temperature and the batch composition are varied. The sec ond stage is coking, with temperature rise at 25°C/h to 550-600°C. The batch consists of industrial air blown pitch (ABP), modified by pitch tar (PT). Oxidation of the ABP, even with a very high final temperature (434°C), does not permit the production of isotropic coke. An analogous result is obtained on adding small portions of PT to the batch (15%). On adding >50% PT, totally isotropic coke may be produced. To obtain coke of isotropic microstructure, the optimal content of PT is 36-41%, and the final air blowing temperature should be high (>390°C). The influence of PT on the structural parameters of the coke is associated with the formation of nonmesogenic structures on air blowing. On coking, these structures suppress the growth of large mesophase. The isotropic coke produced has the following characteristics: limited expansion in the range 1300-2400°C; high structural strength; and optimal density. Graphite based on such coke is consider ably superior to graphite based on industrial pitch coke in terms of its compressive strength, density, and elec trical resistivity.

No abstract

No abstract

No abstract

No abstract

No abstract

No abstract