Preparation method of low-ash mesophase pitch

Abstract

The invention provides a preparation method of low-ash high-property mesophase pitch. The method comprises the steps that the raw material coal tar is purified, a fraction is put into a reaction kettle, temperature programming and heat preservation are conducted in sequence, and purified coal tar pitch is obtained. The purified coal tar pitch and a co-carbonization agent are mixed, the mixture is added into a high pressure reactor, under certain pressure condition, the temperature is increased to a certain temperature, then heat preservation is conducted, and the mesophase pitch is obtained. According to the method, a series of physical methods such as gravity settlement centrifugation and circulating filtration are adopted to purify the coal tar, the very good effect of removing ash impurities is achieved, quinoline insoluble matter formed by mesophase is especially hindered, the content of the mesophase pitch ash is lower than 50 ppm, the content of mesophase reaches up to 100%, and carbon fibers with excellent properties can be prepared continuously; meanwhile, by mixing the pitch with the co-carbonization agent, the rheological property of the mesophase pitch is improved. Compared with a coal tar pitch purification process, the coal tar purification technology is simple, the cost is low, and the high-purity purified coal tar pitch can be obtained through preparation, so that the low-ash high-property mesophase pitch is obtained.

Description

technical field [0001] The invention relates to the preparation of mesophase pitch by thermal polymerization, in particular to the purification of coal tar and the preparation of mesophase pitch by co-carbonization. Background technique [0002] Mesophase pitch is a typical carbonaceous mesophase raw material, which is the necessary stage to obtain graphitized carbon materials. Mesophase pitch has properties such as high carbonization yield and easy graphitization, and is widely used in the preparation of high value-added carbon materials such as pitch-based carbon fibers, graphite fibers, carbon / carbon composites, and needle coke for ultra-high-power electrodes. [0003] Coal tar pitch, petroleum pitch and pure aromatic compounds are the main raw materials for preparing mesophase pitch. Although pure aromatic compounds have low heteroatom content, single composition structure, convenient molecular structure design, regular molecular structure, narrow molecular weight distr...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem that coal tar pitch is difficult to purify, the present invention selects coal tar as a raw material, and starts to purify directly from coal tar

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