| The coal-tar is a by-product, which is very complex and contains high carbon content. The mesophase refers to the liquid crystal substance formed from coal tar to solid semi-coke, which has ordered structure' and played an important role for the formation of needle coke. How to realize the ordered growth controlled for mesophase structure for manufacture of advanced carbon material has being concerned by many scientists.This work mainly studied the influence of pressure on the formation of coal mesophases which belonged to needle coke textile under the electric field. The experiment uses the settling process, heating centrifuge process, the solvent extraction and acid treatment to carry on deal with the raw material for the removal of ash and quinoline. The effect of some important factors, such as centrifugal speed, centrifugal time, distillation temperature, acid type and concentration, types of solvent and the ratio of material to solvent, were explored. The prepared material was carbonized at various conditions. The sample was analyzed by XP-600 polarizing light microscope, XRD and thermal analyzer. The main findings are as following:1) The content of ash in coal tar is reduced from 0.36% to 0.01% when the operation conducted at the temperature of 80℃,0.05mol L-1 hydrochloric acid, centrifugal speed of 4000 r/min. The removing rate of ash is 97.2%. With the methods of solvent treatment the removal rate of QI has better purpose. When solvent is the mixture of toluene and diesel oil (volume ratio=1:1), the centrifuge time is 10 min, the content of QI is reduced from 2.98wt% to 0.59wt% for the coal tar. The removing rate arrives at 80.2%.2) The experiments showed that the content of anisotropy mesophase is highest when heating rate is:1-3℃/min, final carbonized temperature is at 500℃, electrical field strength is 15 kV/m, and the pressure of reaction of 0.6MPa is employed.
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