氧化球团在熔渣中熔化过程的数值模拟

Numerical Simulation of Melting Process of Iron Oxide Pellet in Molten Slag

基于一维非稳态导热原理建立了球团在熔渣中熔化的数学模型，并采用有限差分方法对模型进行求解．通过编程计算，分析了不同条件对球团渣壳熔化时间的影响．计算结果与球团在熔渣中的熔融实验结果相近．球团渣壳在1450，1500，1550℃渣浴中渣壳熔化时间为56，36，25S，渣壳最大厚度分别为0．211，0．149和0．109cm；随着渣浴温度升高、球团初始温度升高，球团熔化速度变快；熔渣碱度在0．8—1．2之间时，球团熔化时间基本无变化，但当碱度继续降低，熔化时间将大幅增长；随着球团金属化率的升高、球团直径的增大，渣壳最大厚度变大，但前者对渣壳熔化时间影响不大，后者使得渣壳熔化时间增长．

On the basis of one-dimension non-steady heat transfer theory, a numerical model of the dynamic behavior of oxide pellet in molten slag was established and solved with finite difference method. The melting time under different conditions was calculated with the model, and the results showed good agreement with the experimental data. The melting time of pellet at 1 450, 1 500, 1 550 ℃ in molten slag bath is 56, 36, 25 s, and the maximum thickness of slag shell is 0. 211, 0. 149, 0. 109 cm, respectively. The melting rate increases with the increase of slag bath temperature and pellet pre-heating temperature. The melting time is almost the same when the slag basicity is in the range of 0. 8 - 1.2, but the melting time increases obviously when the basicity is below 0. 8. The maximum thickness of slag shell increases with the increase of pellet metallization ratio and diameter, but the former has less effect on melting time than the latter.