Study On The Effect Of Coking Coal Particle Size On Its Properties And Coke Quality

The coking capacity of coking coal not only depended on the caking capacity of coking coal,but also was affected by the particle size of coking coal.To study the influence of the grain size of coking coal on its caking capacity and the coking capacity,so as to adjust the size and size distribution of various coal types in the blended coal during production,and selected the appropriate coal fineness,was of great significance for stabilizing and improving coke quality.Through to the coal samples with different grain size of several coking coal commonly used by a coking enterprise,the microscopic coal features analysis,industrial analysis,process property analysis and crucible coke experiment were carried out.Research indicated:(1)The property of coal sample of the same coking coal with different particle size were different.With the increase of its particle size,the vitrinite content of the same coking coal decreased,and the inertite content increased.Fat coal,coking coal and lean coal with a higher degree of metamorphism had a higher average maximum reflectance value of vitrinite in coal sample with a grain size of >6mm than coal sample with a grain size of <6mm,but the average maximum reflectance of the vitrinite group of 1/3 coking coal and gas-fat coal with a lower degree of metamorphism wouid not change with the change of grain size.The same coking coal had a higher ash content when the grain size was <0.5mm and >13mm,and the volatile content was the highest when the particle size was <0.5mm and the lowest when the grain size was >13mm.(2)For coking coal with poor caking capacity,when the grain size was less than0.5mm,the corresponding crucible coke had the smallest reactivity(PRI),and the largest post-reaction strength(PSR),microstrength(MSI)and coke anisotropy index OTI value.For coking coal with good caking capacity,when the grain size was0.5?3mm,the correspongding crucible coke had the smallest PRI and the largest PSR,MSI and OTI value.(3)In actual production,the fineness of coal blended was reduced by 70% from76%,the proportion of coal samples with a grain size of <0.5mm decreased,and the bulk density of coal increased,and the output of coke produced oven increased.The content of coke powder in the coke produced was reduced,and the content of coke with a lumpiness> 80 mm increased.And the blending ratio of coking coal and fat coal in the combined coal was reduced,and the quality of the coke produced remained stable.