干燥过程中褐煤的热膨胀及破碎特性  

THERMAL EXPANSION AND FRAGMENTATION PROPERTIES OF LIGNITE IN DRYING PROCESS

作　　者：孙南翔[1,2] 曲思建[2,3] 白向飞 

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]煤炭科学技术研究院有限公司北京煤化工研究分院,北京100013 [3]煤炭资源高效开采与洁净利用国家重点实验室,北京100013

出　　处：《煤炭转化》2016年第3期6-10,共5页Coal Conversion

基　　金：国家重点基础研究发展计划(973)项目(2014CB744302);国家自然科学基金资助项目(51174270)

摘　　要：利用静态热机械分析法(TMA)测定三种煤样的热膨胀特性,分析煤质特性对热膨胀性的影响,通过滚筒干燥实验,研究干燥过程中不同作用力加载方式、温度和煤质对破碎特性的影响,以及热膨胀与破碎特性的相关关系.结果表明,不同煤种的热膨胀特性差异较大,最大膨胀率和最大收缩率均与原煤全水分存在正相关关系;干燥过程中,热力和机械外力两种作用力的耦合加载方式相较单独加载方式产生了协同效应,其中热力作用使褐煤孔隙和裂隙结构发生变化,颗粒机械强度降低,而机械外力的作用使破碎现象更为显著,且细粒级产量大幅增多;褐煤的热膨胀和破碎特性相一致,原煤全水分越高,热膨胀性越强,在干燥过程中也越易发生破碎及粉化.Thermal expansion property of three lignites were determined using static ther-too-mechanical analysis （TMA）, and the effect of coal characteristics on thermal expansion prop- erty was analyzed. The influence of different loading ways of force, temperature, coal characteristics on the fragmentation behavior, and correlation between thermal expansion and fragmentation were researched through roller drying experiments. The results show that the thermal expansion property varies among three lignites, maximum expansion and shrinkage was positively related to raw coal moisture. In drying process, coupling loading way of thermal and mechanical force produced a synergistic effect than single loading way, thermal force caused the evolution of pore and crack structure, mechanical strength of particle was reduced, and external mechanical force made fragmentation phenomenon more pronounced meanwhile quantity of fine particles increased significantly. Thermal expansion and fragmentation characteristics of lignite had negative correlation, the higher the raw coal moisture content, the stronger the thermal expansion property, more prone to breakage and pulverization.

关 键 词：热膨胀 破碎 粉化 粒度分布 TMA 

分 类 号：TQ536[化学工程—煤化学工程]