A kind of preparation method of isotropic high softening point coal tar pitch

Abstract

The invention discloses a preparation method of isotropic coal pitch with a high softening point. The method comprises the following steps: 1) removing ash and quinoline insolubles in medium-temperature coal pitch by using a disc centrifuge to obtain modified medium-temperature coal pitch; 2) reacting the modified medium-temperature coal pitch at 120-180 DEG C based on an electrophilic iodinationassistance technology for 2-4 h with chemical reagents such as sulfuric acid as a catalyst to prepare coal pitch with the high softening point; and (3) removing light components in the prepared coal pitch with the high softening point by taking an organic solvent as an extractant and adopting an extraction technology so as to obtain the coal pitch with the isotropic structure and the high softening point. The softening point of the prepared high-softening-point coal pitch is 180-290 DEG C, the carbon residue rate is 60-78%, the content of toluene solubles is lower than 10%, the content of quinoline insolubles is lower than 5%, and the molecular structure is isotropic. The method promotes refinement of the coal chemical industry in China, and accelerates the development of carbon, electrolytic aluminum, automobiles and aerospace industries in China.

Description

Technical field: [0001] The invention relates to a preparation method of isotropic high softening point coal tar pitch, in particular to a high softening point coal tar pitch with high softening point, high residual carbon rate, low ash content, narrow molecular weight distribution and isotropic molecular structure method of preparation. Background technique: [0002] Medium-temperature coal tar pitch is obtained by distillation and separation of coal tar as a raw material. Its softening point is generally 70-120°C. It is mainly used as an impregnating agent for high-power graphite electrodes, a binder for electrolytic aluminum anodes, or graphite for lithium-ion batteries. The coating material of the negative electrode material. Since the domestic coal coking industry produces about 5 million tons of medium-temperature coal tar pitch every year, the market competition for medium-temperature coal tar pitch is very cruel. Therefore, the development of high-quality and high-s...

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Problems solved by technology

2) Although the higher the QI content, the higher the residual carbon rate of high softening point coal tar pitch will be, but its rheological properties in the liquefied state will become worse during use, which will affect its practical application effect

3) Affected by factors such as thermal field distribution, gas distribution and high viscosity of the oxidation reactor, the stability of the physical and chemical properties of high softening point coal tar pitch is difficult to control

4) Since there is no domestic centrifugal equipment capable of deashing at a temperature of 250-350°C, the ash content of high softening point coal tar pitch is higher than 500ppm, and the metal components in these ash will be released in downstream products (such as pitch-based carbon fiber) In the process of high temperature carbonization (800~1600℃), it plays the role of catalyst and causes some negative effects, such as the production of pitch-based carbon fiber is prone to broken wires or hairs, etc.

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