Preparation method of coal based needle coke

Abstract

The invention discloses a preparation method of coal based needle coke, which comprises the following steps of: 1) adding a raw material and a diluent into a stirring kettle, stirring and separating out the solvent insoluble matter; 2) heating the mixed liquid in a 1# tubular heating furnace, and feeding the mixed liquid into a pressing hot filtration kettle; 3) filtering, filling an inert gas, pressing and performing hot filtration; 4) performing centrifugal filtration of the filtrate, and feeding the obtained purified raw material into a purified raw material tank; 5) heating the purified raw material in the 1# tubular heating furnace and performing reaction tower circular condensation polymerization, fractionating the escape component to obtain gas, light oil and heavy oil, and recycling the light oil; 6) heating the condensation polymerization concentrate in a 2# tubular heating furnace, coking by a coke tower to obtain coke, and feeding the coke oil gas into a reaction tower; and 7) feeding the prepared green coke into a calcinator, heating and calcining to obtain the product needle coke. The content of quinoline insoluble (QI) in the prepared refined purified asphalt is less than 0.15%, the yield is improved by 10-20%, the coefficient of thermal expansion of the needle coke is low, the pipeline blockage can be avoided, and the material reaction is uniform.

Description

technical field [0001] The invention belongs to a method for preparing needle coke, in particular to a method for preparing coal series needle coke. Background technique [0002] Needle coke is a high-quality variety vigorously developed among carbon materials. Its appearance is a silver-gray porous solid with metallic luster. Its structure has obvious fibrous or needle-like texture. have a larger aspect ratio. Needle coke is a high-quality material for manufacturing high-power and ultra-high-power graphite electrodes. Graphite electrodes made of needle coke have low resistivity, small thermal expansion coefficient, strong thermal shock resistance, high mechanical strength, and strong oxidation resistance. It has the advantages of low electrode consumption and large allowable current density. [0003] According to different raw materials, needle coke is divided into two types: oil-based and coal-based. At present, the countries that produce oil-based needle coke in the wo...

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Problems solved by technology

[0008] Although the above-mentioned patented technology can remove the impurities in the raw material asphalt, it has the following disadvantages in practice: (1) There are too many residues left by flash evaporation, the obtained raw material has low aromaticity, low coke value, and small coke yield , the yield of needle coke is low; (2) The fraction of the flash oil is wide, and during the polycondensation process, the heavier fraction is prone to slagging, causing pipeline blockage; (3) It is easy to form a mosaic structure, resulting in poor coke pulling effect, Reduced quality of needle coke

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