多孔褐铁矿磁化还原特性的模型构建及数值模拟  

Modeling and Numerical Simulation on Magnetization Reduction Characteristics of Porous Limonite

作　　者：朱超 龚志军 李保卫 武文斐 

机构地区：[1]内蒙古自治区白云鄂博矿多金属资源综合利用国家重点实验室,内蒙古包头014010

出　　处：《过程工程学报》2014年第4期637-642,共6页The Chinese Journal of Process Engineering

基　　金：内蒙古应用技术研究与开发资金资助项目(编号:20130310);内蒙古高校创新团队研究计划资助项目(编号:NMGIRT1406);白云鄂博矿多金属资源综合利用国家重点实验室资助项目(编号:BO-13-006)

摘　　要：根据流化床内褐铁矿粉实际还原焙烧情况,建立了微空间尺度下气固还原反应的动力学模型,包括颗粒内非稳态的传热方程、孔隙内气体传输方程和基于描述孔径分布的改进随机孔模型的非均相化学反应动力学方程,采用全隐式有限体积法对控制方程进行数值求解.结果表明,模型预测结果与实验结果吻合较好.温度提高50 K,还原所需时间可缩短36%,褐铁矿焙烧反应速率与还原气体CO浓度近似成正比.磁化焙烧温度为870 K及CO浓度为2.624mol/m3时焙烧时间可缩短至60 s.Based on the actual situation of magnetization reduction roasting of limonite particles in a fluidized bed, a microscopic kinetics model of gas-solid reduction reaction was established. The model included the unsteady heat transfer equation within the particles, gas transport equation in pores and heterogeneous chemical kinetic equation based on the improved random pore model describing the pore size distribution. Finite difference method with implicit formulation was applied to solve the set of governing equations. The results of numerical simulation were consistent with the experimental TG results. It was indicated that if the temperature was raised 50 K, the reduction time would be shortened by 36%. The roasting reactivity was nearly proportional to the CO concentration. The roasting time could be shortened to 60 s when the roasting temperature was 870 K and CO concentration 2.624 mol/m3.

关 键 词：褐铁矿 磁化焙烧 还原 数值模拟 动力学 

分 类 号：TK553.1[动力工程及工程热物理—热能工程]