王意博,李显,马金荣,等. 高热强度型煤制备机理与热转化行为研究[J]. 中国矿业,2023,32(12):202-211. DOI: 10.12075/j.issn.1004-4051.20230177
    引用本文: 王意博,李显,马金荣,等. 高热强度型煤制备机理与热转化行为研究[J]. 中国矿业,2023,32(12):202-211. DOI: 10.12075/j.issn.1004-4051.20230177
    WANG Yibo,LI Xian,MA Jinrong,et al. Study on preparation mechanism and thermal conversion behavior of high thermal strength briquette[J]. China Mining Magazine,2023,32(12):202-211. DOI: 10.12075/j.issn.1004-4051.20230177
    Citation: WANG Yibo,LI Xian,MA Jinrong,et al. Study on preparation mechanism and thermal conversion behavior of high thermal strength briquette[J]. China Mining Magazine,2023,32(12):202-211. DOI: 10.12075/j.issn.1004-4051.20230177

    高热强度型煤制备机理与热转化行为研究

    Study on preparation mechanism and thermal conversion behavior of high thermal strength briquette

    • 摘要: 为了高效利用新疆地区日益增长的粉煤资源,最简单有效的解决手段是将粉煤制备成型煤,型煤的优劣可以通过冷态抗压强度和热强度进行判断。本文选取沥青渣作为黏结剂,提出了热预处理提升型煤热强度的方法,研究了工艺关键参数对热强度提升的效果和机理,并计算了型煤产品的燃烧动力学参数。研究结果表明,以沥青渣为黏结剂的冷压型煤冷态抗压强度为10.9 MPa、热强度为0 MPa;250 ℃热预处理后型煤的冷态抗压强度为9.8 MPa,热强度为21.5 MPa;450 ℃热预处理后型煤的冷态抗压强度为8.5 MPa,热强度为35.3 MPa。热预处理过程中提升了型煤内颗粒之间的固体桥联联结力,在250 ℃时,随着沥青渣的软化,熔融分散,再冷却形成固桥提升热强度,只发生了物理变化;在450 ℃时,由于热预处理导致型煤内部发生化学反应,在接触面反应完成后形成稳定的大分子结构,导致热强度提升。采用不同的机理函数对型煤的活化能、指前因子和相关系数进行计算,对比相关系数的结果显示,型煤产品的燃烧遵循二阶反应动力学。研究内容为制备高热强度型煤和完善型煤热强度提升机理提供了支撑。

       

      Abstract: To efficiently utilize the growing pulverized coal resources in the Xinjiang Region, the simplest and most effective solution is to prepare briquette. The quality of briquette can be assessed by its cold compressive strength and thermal strength. This paper selects asphalt pitch as the binder and proposes a method of thermal pretreatment to enhance the thermal strength of briquette. It explores the effect and mechanism of key process parameters on improving thermal strength and calculates the combustion kinetics parameters of the briquette product. The results show that the cold compressive strength of briquette with asphalt pitch binder is 10.9 MPa, and its thermal strength is 0 MPa. After thermal pretreatment at 250 ℃, the cold compressive strength is 9.8 MPa, and the thermal strength is 21.5 MPa. After thermal pretreatment at 450 ℃, the cold compressive strength is 8.5 MPa, and the thermal strength is 35.3 MPa. The thermal pretreatment process enhances the solid bridge bonding between particles in the briquette. At 250 ℃, the softening and melting dispersion of the asphalt pitch followed by cooling forms solid bridges, increasing the thermal strength through physical changes. At 450 ℃, chemical reactions occur within the briquette due to thermal pretreatment, forming stable macromolecular structures upon completion of the reaction at the contact surface, thereby increasing the thermal strength. Different mechanistic functions are used to calculate the activation energy, pre-exponential factor, and correlation coefficient of the briquette, and the comparison of correlation coefficients shows that the combustion of the briquette product follows second-order reaction kinetics. The research provides support for the preparation of high thermal strength briquette and the refinement of mechanisms to enhance its thermal strength.

       

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