基于改进分段尝试法的高炉热储备区焦炭熔损反应过程动力学机理  

Kinetics mechanism of coke solution loss reaction in thermal reserve zone of blast furnace by modified sectioning method

作　　者：折媛[1,2] 张文哲 湛文龙 朱利[2] 吴铿[2] SHE Yuan;ZHANG Wenzhe;ZHAN Wenlong;ZHU Li;WU Keng(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Materials and Metallurgy,University of Science and Technology,Liaoning 114000,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]北京科技大学冶金与生态工程学院,北京100083 [3]辽宁科技大学材料与冶金学院,辽宁鞍山114000

出　　处：《中南大学学报（自然科学版）》2021年第12期4227-4237,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51904223,51974154,51604148,51474022);陕西省自然科学基金资助项目(2020JQ-674)。

摘　　要：采用改进分段尝试法研究高炉热储备区条件下焦炭熔损反应过程的动力学机理,针对不同条件(包括焦炭粒度、气体成分及装料方式等)下焦炭熔损反应过程分别建立前期化学反应控速的随机孔模型与后期扩散传质控速的收缩核模型,确定不同控制环节的转换时间点及相关动力学参数。研究结果表明:增大焦炭粒度有利于降低焦炭熔损反应速度;提高还原煤气中CO_(2)体积分数会加剧焦炭熔损反应;混装比层装更有利于降低焦炭熔损反应速度;前期化学反应的速率常数比扩散传质系数高出2~3个数量级,且其拟合系数明显高于后期分子扩散拟合系数;在焦炭熔损反应过程后期,在近平衡区域内,建立了化学反应对扩散传质干涉的方程,提高了分子扩散过程数据拟合的相关系数,确定了反应后期的扩散系数,并提出了反应后期扩散传质控速的修正方程。The kinetics mechanisms of coke solution loss reaction process in the thermal reserve zone of blast furnace were studied using the modified sectioning method.Different conditions such as coke particle,gas component and charging methods were taken into account in the experiments.A random pore model for the chemical reaction rate control in the initial stage and a shrinking core model for the diffusion mass transfer rate control in the later stage were established,respectively.The conversion point and related kinetic parameters of different controlling stage were determined.The results show that it is helpful to decrease the rate of coke solution loss reaction by increasing the coke particle size.Higher CO_(2) volume fraction in reducing gas accelerates the rate of coke solution loss reaction and mixed charging is better than ordinary charging to decrease the rate of coke solution loss reaction.Besides,the rate constant of chemical reaction in the initial stage is 2-3 order of magnitudes higher than that of diffusion mass transfer.The fitting coefficient of the initial stage is obviously higher than that of the later stage.In the later stage of coke solution loss reaction process(near equilibrium region),the interference equations of chemical reaction on diffusion mass transfer are established.The correlation coefficients of data fitting in the molecular diffusion process are improved.The chemical reaction diffusion coefficient at the later stage of the reaction is determined,and a modified equation for mass transfer rate control at the late stage of the reaction is proposed.

关 键 词：改进分段尝试法 熔损反应 动力学参数 不可逆过程热力学 近平衡区域 

分 类 号：TF526.1[冶金工程—钢铁冶金] TF01