Fine purification method for coal tar pitch

Abstract

The invention relates to a coal tar pitch refining method, in particular to a method for refining pitch for coal tar pitch needle coke, impregnant and binding agent for manufacturing high-power and ultrahigh-power graphite electrodes and pitch for manufacturing coal tar pitch carbon fibers. The method is characterized in that the method comprises the following steps: diluting coal tar pitch and the liquid containing coal tar pitch with organic solvent at a weight ratio of the organic solvent to coal tar pitch and the liquid containing coal tar pitch of 1:(5 to 30), removing impurities in the pitch solution by the combination of separation by a centrifuge and filtering with an organic film, and distilling and recovering the solvent in the refined mixture solution to obtain the coal tar pitch free of quinoline insoluble materials. The method has the advantages of good continuity of the separation process and high efficiency, and the pitch contains no quinoline insoluble materials.

Description

A kind of refining method of coal tar pitch technical field The invention relates to a coal tar pitch needle coke raw material for preparing high-power and ultra-high-power graphite electrodes, a coal tar pitch impregnating agent, refined pitch for a coal pitch binder, and a pitch refining method for preparing coal pitch carbon fibers. Background technique At present, high-power and ultra-high-power graphite electrodes require high electrical conductivity and small thermal expansion coefficient. The existence of impurities in raw materials will seriously affect their electrical properties and mechanical strength; during the process of carbon fiber melt spinning, the existence of impurities will lead to discontinuous spinning , the thickness of the wire is uneven, and the strength is seriously affected. They have high requirements for the raw material pitch. At present, domestic coal tar pitch is mainly a by-product of coking, and impurities will inevitably be introduced du...

AI Technical Summary

Problems solved by technology

"Chinese Patent" Patent No.: CN00119077.6 and "Chinese Patent" Patent No.: CN200410023366.7 mention the use of inorganic membranes for the filtration and washing of ultrafine powders and the purification of mixed vegetable oils, but in the refining process of coal tar pitch It has not been used yet. At the same time, there is a defect in inorganic membrane separation. It is a concentration process. When the refined product liquid is obtained, the concentrated product liquid containing a large amount of impurities is obtained. If it is not recycled, it will cause product loss.