【摘要】 灰分对焦炭气化反应行为的影响至关重要,尤其是灰分中含量最高的SiO₂,其作用机制仍缺乏充分认识。通过向炼焦煤中掺混不同水平的SiO₂制备焦炭,研究了SiO₂含量和反应温度对焦炭气化行为的影响,结合光学组织和微孔定量分析阐明了焦炭微观结构对其气化行为的作用机制。结果表明:（1）气化温度升高会导致焦炭反应速率显著加快,反应时间提前。（2）SiO₂对焦炭气化反应的影响依赖于其浓度和反应温度,在1 100℃时,SiO₂基本不表现出催化作用;而在1200℃和1300℃,添加量为0.5%～5.0%的SiO₂表现出一定的正向催化作用。（3）微观结构分析进一步表明灰分中SiO₂一方面抑制焦炭石墨化,增加活性位点,有助于提高气化反应活性;另一方面熔融灰分堵塞气孔,阻碍CO₂内扩散降低了反应速率,综合表现出较弱的催化效果。更多还原

【Abstract】 The effects of ash content on the gasification reaction behavior of coke are of vital importance,especially the effects of SiO₂ content,the highest one in ash.However,the mechanism of its action is still not fully understood.In this study,different contents of SiO₂ are blended in the coking coal for coke preparation to figure out the effects of SiO₂ content and corresponding reaction temperature on the gasification behavior of coke,based on which,the action mechanism of the coke microstructure on coke gasification behavior is elucidated through optical texture analysis and micro-pore quantitative analysis.The results show that（1） Increase of gasification temperature will boost the coke reaction rate,resulting in earlier reaction.（2） The effects of SiO₂ on the coke gasification reaction depends on its content and reaction temperature:at 1100℃,SiO₂almost does not pose catalysis;at 1200℃ and 1300 ℃,SiO₂ with content accounting for 0.5%-5.0% exhibits some positive catalytic effect.（3） In further,microstructure analysis indicates that,on the one hand,SiO₂ in ash inhibits the coke graphitization and increases active sites,which conducive to improving the activity of gasification reactions;on the other hand,the molten ash blocks the pores,which affects the internal diffusion of CO₂ and decelerate the reaction speed,demonstrating an overall relatively weak catalytic effect.更多还原