神木块煤热解过程中机械强度演变规律  

Evolutionary Pattern of Mechanical Strength during Pyrolysis Process of Shenmu Lump Coal

作　　者：李彬 李信 施瑞盟[1] 邹冲[1] 马成 李彦雄 LI Bin;LI Xin;SHI Ruimeng;ZOU Chong;MA Cheng;LI Yanxiong(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;School of Electronic Information,Xijing University,Xi'an 710123,China;Inner Mongolia Zhengneng Chemical Industry Group Co.,Ltd.,Ordos 017200,China)

机构地区：[1]西安建筑科技大学冶金工程学院,西安710055 [2]西京学院电子信息学院,西安710123 [3]内蒙古正能化工集团有限公司,内蒙古鄂尔多斯017200

出　　处：《煤炭技术》2024年第12期243-248,共6页Coal Technology

基　　金：鄂尔多斯市科技计划资助项目(2022YY037);陕西省教育厅服务地方专项资助项目(22JC042)。

摘　　要：半焦的机械强度对其在铁合金、电石等领域应用效能影响较大,探究块煤在热解过程中机械强度的变化规律及其机理可为制备高强度半焦提供依据。对2种神木低阶块煤在不同热解温度下制备的半焦进行了机械强度测定,通过光学显微镜观察了半焦孔隙与裂纹的演变过程,并分析了半焦微观结构对机械强度的影响机制。结果表明,随着热解温度的提高,半焦的机械强度呈现“W”形变化趋势。2种半焦机械强度的极大值与极小值分别相差6.4%和8.8%。当热解温度达到500℃左右时,半焦的机械强度出现最小值。随着温度升高,半焦机械强度分别在600℃和800℃左右出现2个极大值。半焦的机械强度与裂纹密切相关,挥发分快速析出过程中裂纹快速生成并发展,致使半焦的机械强度降低。研究结果揭示了热解温度对半焦机械强度的影响规律,为高强度半焦的制备提供了理论支持。The mechanical strength of semi-coke significantly influences its application efficiency in various fields such as ferroalloys and calcium carbide production.Investigating the variation patterns and mechanisms of mechanical strength during the pyrolysis process of lump coal can provide a basis for producing high-strength semi-coke.The mechanical strength of semi-coke prepared from two types of low-rank lump coal from Shenmu was determined at different pyrolysis temperatures.The evolution of pore structure and cracks in semi-coke was observed using optical microscopy,and the impact mechanism of the microstructure on mechanical strength was analyzed.The results indicate that the mechanical strength of semi-coke exhibits a"W"shape trend with increasing pyrolysis temperature.The maximum and minimum values of mechanical strength for the two types of semi-coke differ by 6.4%and 8.8%,respectively.The mechanical strength of semi-coke reaches its minimum value at around 500℃pyrolysis temperature.With further temperature increase,two peaks in mechanical strength occur around 600℃and 800℃,respectively.The mechanical strength of semi-coke is closely related to cracks,with cracks formingand developing rapidly during the rapid volatilization process,leading to a decrease in mechanical strength.These findings reveal the influence of pyrolysis temperature on the mechanical strength of semi-coke,providing theoretical support for the production of high-strength semi-coke.

关 键 词：半焦 机械强度 热解温度 微观结构 裂纹 

分 类 号：TQ530[化学工程—煤化学工程]