半焦与烧结矿的混合还原反应过程动力学

Kinetics of mixed reduction process of semi-coke and sinter

为了研究添加半焦对烧结矿还原行为的影响以及确定还原过程反应动力学机理,通过在散料层内添加不同比例的半焦,测定不同半焦比例下烧结矿的还原性能,考察了还原度与还原速率的变化情况,确定了不同阶段下烧结矿的还原机理。采用分段尝试法对其还原反应过程动力学进行分析,确定出反应过程前期和后期不同的机理函数,进而通过建立动力学模型,计算得到了不同阶段的反应动力学参数。实验结果表明,不同阶段动力学模型进行数据拟合的结果与实验数据吻合得较好,相关系数都大于0.99。随着半焦添加比例的升高,还原反应前期的反应速率常数krea升高,还原反应后期的有效扩散系数DABP增大。

In order to study effect of addition of semi-coke on sinter reduction behavior and confirm kinetic mechanism of reduction process,different proportions of semi-coke were added in the bulk layer to measure the reducibility of sinter and inspect the changes of reduction degree and rate.The reduction mechanisms of sinter at different stages were confirmed.By applying subsection attempting method to analyze kinetics of reduction process,different mechanism functions of the reaction process at earlier stage and later stage were determined.Furthermore,kinetic models were established and related kinetics parameters were figured out.The results of data-fitting show that the kinetic models at different stages are in good agreement with experimental data and the correlation coefficients are greater than 0.99.With the increase of semi-coke proportion,the reaction rate constant kreaof the reduction reaction at the earlier stage rises,and the effective diffusion coefficient DABPat the later stage rises.