PITCH COKE QUALITY

摘要

Oil refineries in Russia have converted from the outdated periodic production of coke in reactors to the progressive semicontinuous method of slow coking in unheated chambers, which has led to an end to the production of special pyrolysis oil coke (grade KNPS). Consequently, the manufacture of constructional and high-density graphites lacks a traditional main raw material source. A comparison has been made of the properties of KNPS coke and cokes produced in Russia from low-sulfur slow-coking oil coke (KZK) and pitch electrode coke (KPE), which has shown that pitch coke from the Mechel company differs favorably from KZK in having a low proportion of sulfur and beinf as low in ash as KNPS. However, the optical microstracture of the pitch electrode coke has a higher score with appreciable fluctuations (Table 1). This means that the structure of KPE is less isotropic and more inhomogeneous than is the case with the replaced KNPS (the isotropic structural components are estimated with a lower score on GOST 26132-84 [1]). The structural inhomogeneity is responsible for considerable fluctuations in the actual density and resistivity.