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Needle coke and carbon materials in the 1970s, great efforts to develop a high-quality coke material, mainly made of graphite electrodes used in electric arc furnace steel, aluminum, etc.. Production of raw materials with coal tar and petroleum asphalt, for the preparation of high-quality needle coke, coal tar pitch is important to take full advantage of the rich resources of coal tar pitch, and the production of high value-added products and reduce dependence on foreign products. Preparation of needle coke this thesis, the solvent method, i.e. first through the mixed solvent centrifugation removed from the coal tar pitch in the quinoline insoluble matter (QI), order of QI LT; 0.1% of the purified pitch investigated the solvent ratio, time of centrifugation, etc. a variety of operating conditions on the QI content and the yield of purified pitch; then purified pitch as raw materials, the thermal polymerization under certain conditions coke formation, effects of different raw materials and the thermal polymerization temperature, time, pressure and other factors coke Finally, the impact of the structure, performance; Calcined coke at high temperature calcined coke, analysis of elemental composition, structure, morphology and properties of coke and calcined coke. The results show that: (1) in the QI centrifugal separation process, the medium temperature pitch, aryl alkoxy ratio to 0.6, and purified pitch QI content minimum, soft pitch, aryl alkoxy ratio for 0.4, purified pitch QI content minimum; solvent than certain when the yield of purified pitch with aralkyl ratio increases with increased; aralkyl than refined asphalt QI content and the yield is constant, with the ratio of solvent decreases; longer centrifugation time, purified pitch QI lower , yield lower; centrifugation elevated temperatures conducive to the QI the removal. Suitable operating conditions is: solvent ratio ≥ 1.0, a rotational speed of 2000rpm, the centrifugation temperature of 80 ° C and centrifugation for 16min, obtained the QI ≤ 0.05% of the purified pitch. (2) in the thermal polymerization process of preparing coke, the raw material, the QI content of the structure of the green coke great influence high QI content impede the orderly development of mesophase, easy to generate a mosaic structure. Thermal polymerization temperature is too low, can not form ordered mesophase; temperature is too high, the preparation of coke ordering often poor and loosely structured. The prolonged thermal polymerization time is conducive to the mesophase spherules fully generate financial and ultimately the formation of non-spherical mesophase WAN streamlined, fibrous coke structure. Heating rate is too fast and easy to generate a sheet of coke and semi-mosaic structure. The pressure is too low, the formation of the random arrangement of the intermediate phase, the pressure is too high, then it is easy to form porous coke and mosaic structure. Stirring operation of the initial reaction contribute to the reaction system composed of the balance of properties such as temperature, to give the acicular structure of the WAN. Airflow pull Jiaoyou Li in order coke, but the pressure relief should be slow. The optimum thermal polymerization conditions as follows: heating rate of 2 ° C min-1 thermal polymerization temperature of 460 ℃, system pressure 0.35MPa, thermal polymerization 20h coke prepared with a well-ordered fiber structure. (3) calcination treatment can be greatly reduced the hetero atoms in the coke, can remove the light components in the coke sample. The calcination can improve the crystal structure of the coke, so that the accumulation of molecular level height increases, arranged between the molecular layers tends to compact. Similar the prepared calcined coke lattice parameter with foreign needle coke true density, ash content standard of performance reached Japan new day.
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