Coal-based needle coke preparation process

Abstract

The invention discloses a coal-based needle coke preparation process which comprises the following steps: 1) feeding raw materials into a No.1 tube heating furnace, heating, feeding into a No.1 flash distillation tower, performing flash distillation, feeding flash distillation oil into a No.2 flash distillation tower, and performing flash distillation to produce refined asphalt; 2) filtering the refined asphalt, injecting inert gas to perform pressurization, and performing hot filtration; 3) performing centrifugal filtration on the filtrate to obtain refined and purified asphalt, and feeding into a purified asphalt tank; 4) feeding the refined and purified asphalt into the No.1 tube heating furnace, heating, performing polycondensation through a polycondensation reaction kettle, fractionating escaping components to obtain oil gas, light oil and heavy oil, mixing the heavy oil and the refined asphalt material produced by the No.2 flash distillation tower, and feeding into the pressurization hot filtration kettle; 5) pumping the polycondensed asphalt into a No.2 tube heating furnace, heating, coking, and feeding coking oil gas and components escaping from the top of the polycondensation reaction kettle into a fractionating tower; and 6) calcining green coke in a calcining furnace to obtain the needle coke product. For the refined and purified asphalt prepared by the method, the quinoline insoluble matter content is less than 0.1%, and the thermal expansion coefficient is low, thereby ensuring that the asphalt can be used for large steel-making electric furnaces.

Description

technical field [0001] The invention belongs to a coking chemical technology, in particular to a process for preparing needle coke with coal tar, coal tar pitch, remixed soft pitch or coal tar fractions as raw materials. Background technique [0002] With the large-scale electric furnace steelmaking and the accelerated growth rate of global electric furnace steelmaking production, the use of ultra-high power electrodes (UHP) is rapidly increasing, and the requirements for carbon raw materials are also getting higher and higher. Needle coke is the aggregate for making ultra-high-power electrodes. When using ultra-high-power electrodes for electric furnace steelmaking, the smelting time can be shortened by 30% to 50%, and electricity can be saved by more than 10% to 50%. The economic benefits are very significant. Needle coke can be divided into oil-based needle coke and coal-based needle coke according to different raw materials. They are respectively made from petroleum resi...

AI Technical Summary

Problems solved by technology

[0007] Among the above-mentioned raw material pretreatment processes, the flash evaporation method and the sedimentation method are relatively simple in operation and low in equipment investment cost, but the purification effect cannot meet the requirements. The centrifugation method has a moderate process and a good purification effect, but the treatment capacity is small

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