炼焦工艺对干煤和湿煤成焦质量的影响

 为了更好地优化炼焦工艺,有效地改善配合煤炼焦的成焦质量,系统性地分析了炼焦工艺及干煤和湿煤炼焦对焦炭强度与反应性的影响。采用5 kg试验焦炉对多种工况下的干煤(水分低于3%)和湿煤(水分高于6%)分别进行炼焦试验。通过研究装炉煤的水分、干基堆密度以及装炉温度对干煤和湿煤成焦强度及焦炭反应性(CRI)的影响,并结合干煤和湿煤成焦的光学组织及炼焦过程焦饼中心升温特征的对比,分析了煤的干、湿条件和不同工况等因素影响最终成焦质量的机理,从而给现场优化炼焦工艺提供理论参考。试验结果表明,水分及装炉温度维持不变时,增加装炉煤的干基堆密度能够有效地改善湿煤和干煤成焦的强度指标;使用水分高于6%的湿煤进行炼焦时,增加水分至8%以上时会对成焦的耐磨强度产生不利影响;使用水分低于3%的干煤进行炼焦时,水分越高,成焦的强度指标越差,将配合煤水分维持在2%左右能够使焦炭的反应性达到较高水平;通过控制加热过程来调控配合煤装炉温度并减少炼焦时间,有利于增强成焦的反应后强度(CSR),但会对焦炭的反应性产生不利影响。

Influence of coking processes on coke quality made by wet coal and dried coal

In order to optimize the coking process and improve the coke quality effectively of coal blending, it is necessary to analyze the influence of coking process and dry cool and wet coal coking on coke strength and reactivity (CRI) systematically.Coking experiments of dry coal (moisture less than 3%) and wet coal (moisture more than 6%) were carried out in a 5 kg experimental coke oven under different working conditions. The effects of moisture content, dry base bulk density and charging temperature of coal on coke strength and reactivity were investigated, combined with the comparison of the optical texture and heating characteristics of coke center in coking process of dry coal and wet coal, and the mechanism of influence on coke quality was analyzed, which provides a theoretical reference for optimizing coking process. The results show that when the moisture and the charging temperature keep unchanged, the strength level of coke can be improved effectively by increasing the dry base bulk density of coal. When coking by wet coal, the moisture of which is higher than 6%, excessive moisture content (more than 8%) is not conducive to improve the wear resistance property of coke. However, when coking by dry coal, whose moisture is less than 3%, and when the moisture increases, the coke strength will decrease. If moisture content of coal is maintained at 2% can make the coke reactivity (CRI) stay at a higher level. By controlling the heating process to adjust the charging temperature and shorter coking time,the post-reaction strength(CSR) of coke could be improved, but the coke reactivity would be reduced.