改进分段尝试法研究焦炭气化反应动力学  

Kinetics of coke gasification reaction process by improved segmentation attempt method

作　　者：折媛[1,2] 湛文龙 邹冲 韩鹏[3] 吴铿[2] SHE Yuan;ZHAN Wen-long;ZOU Chong;HAN Peng;WU Keng(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,Shaanxi,China;State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China;School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114000,Liaoning,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]北京科技大学钢铁冶金新技术国家重点实验室,北京100083 [3]辽宁科技大学材料与冶金学院,辽宁鞍山114000

出　　处：《钢铁》2022年第4期12-24,共13页Iron and Steel

基　　金：国家自然科学基金资助项目(51904223,51974154,51604148);陕西省自然科学基金资助项目(2020JQ-674);榆林市科技局产学研资助项目(Z20200396)。

摘　　要：焦炭作为高炉炼铁的主要燃料,对高炉的正常运行以及高效冶炼发挥着至关重要的作用。伴随着现代高炉大型智能化的发展趋势,面对资源的不断消耗,用于冶炼优质冶金焦的原料逐渐减少,低质冶金焦引起了冶金工作者越来越多的关注。在测定高炉使用的焦炭基础理化特性后,通过对不同升温速率下不同质量焦炭与CO;的气化反应试验,采用分段尝试法建立焦炭气化反应过程动力学模型,探究焦炭气化反应过程控制机理。在非等温条件下,将反应过程分成前期化学反应控速和后期内扩散控速2个阶段。通过用2个阶段不同控速模型对气化反应过程数据进行拟合,分别建立了前期化学反应控速的未反应核模型与后期扩散传质控速的收缩核模型。给出了反应过程中2种控速的转换点和化学反应速度常数及扩散传质系数。讨论影响反应动力学参数的因素和分析产生补偿效应的原因。考虑到化学反应速度比扩散传质速度高出近3个数量级,根据不可逆热力学的唯象方程,研究在气化反应后期近平衡区域内化学反应过程对扩散传质过程的干涉效应并建立相关唯象方程,在确定化学反应扩散系数后,对焦炭气化后期扩散传质控速方程进行了修正,改进了适合冶金反应工程学研究反应过程动力学的分段尝试法,进一步提高了其精确度。As the main fuel of blast furnace ironmaking,coke plays a vital role in the normal operation of blast furnace and efficient smelting.With the development trend of large-scale intelligence of modern blast furnace and the continuous consumption of resources,the raw materials used to smelt high-quality metallurgical coke are gradually reduced.Low-quality metallurgical coke has attracted more and more attention of metallurgical workers.After determining the basic physical and chemical properties of coke in blast furnaces,the kinetics of different quality coke and CO;gasification reaction processes under different heating rates were studied using the segmentation attempt method.The control mechanism of coke gasification reaction process was studied,which could be divided into two stages,the chemical reaction rate control in the early stage and the diffusion mass transfer rate control in the later stage.A two-stage speed control model was used to fit the gasification reaction process data,and then an unreacted shrinking core model for the chemical reaction rate control in the early stage and a shrinking core model for the diffusion mass transfer rate control in the later stage were established respectively.The conversion points,chemical reaction rate constant and mass transfer coefficient of the two control rates in reaction process were determined.Considering that the chemical reaction rate was nearly three orders of magnitude higher than the diffusion control rate,according to the irreversible thermodynamic phenomenological equation,the interference effect of chemical reaction process on the internal diffusion rate control process in the later stage of gasification reaction process was studied,and the valence coefficient in the phenomenological equation was determined.The latter diffusion speed control equation was modified,segmentation attempt method which was suitable for metallurgical reaction engineering to study reaction process kinetics was improved and its accuracy was further increased.

关 键 词：焦炭气化 分段尝试法 反应过程动力学 不可逆过程热力学 冶金反应工程学 

分 类 号：TF53[冶金工程—钢铁冶金]