Research On Forming And Coking Properties Of Coking Coal Powder

Upsizing of the blast furnace is an important direction of steel metallurgy industry,but it has a higher quality of coke.Especially the large blast furnace’s need on the top loading coke oven prompts metallurgical joint enterprise’s top loading coke oven construction.The top loading coke oven in the process of loading have pulverized coal’s overflow which caused environmental pollution.Although the ground dust removal station can be used during coal loading and the waste gas derived from the rising pipe can be sprayed with high-pressure ammonia water,the related pollution problems such as dust overflowing from the coal loading port and waste gas generated by dust pyrolysis in the process of coal loading remains important environmental problems for coking enterprises.The fine powder forming in the process of top loading coking is an important technical way to solve this problem.Aiming at the environmental pollution caused by the overflow of pulverized coal in the process of loading in the top loading coke oven of coking enterprises,this thesis carried out the targeted research on the forming and coking performance of micro-powder.Experiment studied the effect on the different granularity,water content,different metamorphic grade powder caused by pyrolysis coking coal pyrolysis process performance,coking coal’s Hardgrove grind ability index,powder formability,formed powder’s physical performances and in focus the coking performance and other related problems using coking enterprises commonly used JD1/3 coking coal,WC lean coal,YL coking coal,TD coking coal,XF coking coal,LH fat coal,JKOK coking coal and PH coking coal,eight kinds of coking coal.Based on the research on the water content of fine powder coal with particle size less than0.5mm,the particle size variation characteristics of coking coal with different metamorphic degrees were obtained.The influence of water content’s increasing in coal on the particle size variation of coking coal was that the mass fraction of particle size >5mm and 5-3mm increased by 1% and 4%,and the mass fraction increased slightly.However,the mass fraction of 3-1mm and 1-0.5mm in medium grain size increased by 23% and 9%,with significant increase,while the mass fraction of<0.5mm in small grain size decreased by 33%,which was significantly decreased.Because of the metamorphic degree of coking coal,its Hardgrove grind ability index is different,and the coking coal has the best grindability,among which the Hardgrove grind ability index of JKOK coking coal is as high as 93.7,while the Hardgrove grind ability index of 1/3 coking coal with lower metamorphic degree is only 40.5,and the Hardgrove grind ability index of WC coal with higher metamorphic degree is 50.9.The Hardgrove grind ability index of LH coal is 51.9.With the decrease of coking coal particle size,the contents of vitrinite in coal increased,while the contents of inertinite decreased.The contents of vitrinite in fat coal,coking coal and lean coal increased by 27%,26% and 24%,and inertinite decreased by 11%,13% and 18%.The pyrolysis experiments of coking coal show that the higher the metamorphic degree is,the higher the activation energy of coal is.The coal with low metamorphic degree produces a large amount of volatilization analysis at 450℃,and the pyrolytic rate of the overflow dust in the process of coal loading is high.The tendency of environmental pollution of the coal with low metamorphic degree increases.The forming experiment of coking coal powder shows that: The porosity,density,compressive strength and falling strength of forming coal with different water ratio are different.The 10% water distribution amount makes the compressive strength and falling strength of forming coal A and forming coal B formed by roller reach the maximum.The compressive strength and falling strength of forming coal A are 13 N and 69%.The compressive strength and falling strength of B forming coal are 25 N and 85%.The coking experiment using 2kg experimental coke oven with forming coal shows that the coke quality is higher than that of single coking with bulk coal.The microstructure strength of coke made with forming coal is 2% higher than that of bulk coal,the structural strength is 1.04% higher,the reactivity of granular coke is4.58% lower,and the strength of granular coke after reaction is 3.72% higher.When the ratio of forming coal is at 20%,The strength and thermal performances of coke tend to be the best.