Investigation On The Effects Of Additives On Coking Coal Desulfurization During Carbonization

NX8 coal,NX9 coal,ML coal,ZCD coal,JX coal,KL coal,WMC and ZST coal were used as raw materials,H₃BO₃,AlCl₃ and MgCl₂ were used as additives,the cationic surfactants of 1231,1631 and 1831 were used as assistant additives.By the method of dipping the coal powder in the additive dilutes,the additives were supported on the coal surface.The sulfur in coking coal was maximum precipitated in the process of carbonization by supporting the additives,which can improve the utilization of high sulfur coking coal.The effect of carbonization conditions,species of additives,additives concentration and species of cationic surfactants on the desulfurization of coking coal and some of its maceral concentrates was investigated.The desulfurization of coking coal during the carbonization on 1.5kg coke oven and the strength of coke was studied.The kinetics of sulfide gas evolution curve of NX8 coal and its maceral concentrates on the fixed bed carbonization were also investigated.The better desulfurization conditions of carbonization were,heating rate 12℃/min,final temperature 900℃,residence time 10min;The desulfurization of NX8 coal,ZCD coal,JX coal and ZST coal were increased,and the sulfur content in coke decreased by adding the additives of H₃BO₃, AlCl₃ and MgCl₂,which concentrations were all 4w%,especially the AlCl₃ and MgCl₂. The desulfurization of NX8 coal,ZCD coal and ZST coal was increased 15.55,14.76, 17.93 percentage point by supporting the additive of AlCl₃.The desulfurization of JX coal was increased 15.95 percentage point after adding MgCl₂.With the concentration of additives increased the sulfur content in coke was decreased and the total sulfur desulfurization was increased.The total sulfur desulfurization of NX8 coal,NX9 coal,ML coal,ZCD coal,JX coal,KL coal,WMC coal and ZST coal was increased 15.55, 9.76,18.66,14.76,12.59,15.36,18.64,17.93 percentage point by the concentration of AlCl₃ increasing to 4w%;The desulfurization were increased for using the cationic surfactants of 1231,1631 and 1831.The shorter the hydrophobic chain,the higher desulfurization it was;The desulfurization order of coal maceral concentrates was VC＞IC＞MC.The promoting order effect of additives on coal maceral concentrates was VC＞IC＞MC.After adding the additives to VC of NX8 coal,ZCD coal,KL coal,WMC coal,desulfurization was increased 18.55,20.18,18.50,22.17 percentage point.NX8 coal and it's maceral concentrates were investigated in the carbonization process of fixed bed,the content of gaseous sulfide in the tail gas was MC＞VC＞IC;The desulfurization of NX8 coal,ZCD coal,KL coal,WMC coal was increased 4.59,4.9, 5.12,8.92 percentage point on 1.5kg coke oven during the carbonization by supporting the additives of AlCl₃ and 1231,which concentration was 4w%and CMC respectively. But the strength of coke after adding the additives was decreased;The sulfide gas evolution kinetic curve of NX8 coal and its maceral concentrates in the process of carbonization could be fit of three or two first-order reaction,the matching effect was preferable.The E of sulfide gas evolution in the process of main carbonization was decreased by supporting the additives of AlCl₃ and 1231,which concentration was 4w% and CMC respectively,and it was beneficial to sulfur evolution;The dynamic model of sulfide gas evolution in the process of carbonization was determined as three steps.The first step was considered as the ones of controlling procedure by analysis of the experiment data and calculation.