分段法研究烧结矿还原的动力学过程

Investigation of the Reduction Kinetics Process of Sinter Ore by Sectional Stepwise Method

根据工业生产烧结矿的还原动力学特点,从冶金传输原理的质量传输和化学反应的基本原理出发,针对还原过程中的不同阶段分别建立了立方体颗粒的化学反应过程动力学和分子扩散过程的新模型.在所建立模型的基础上采用分段法研究了CO还原烧结矿的反应过程动力学,得出不同限速性环节转换的时间点和相关的动力学参数,进而给出了动力学参数与温度的关系式.通过对工业生产烧结矿还原过程中的微观结构变化的观察验证了该模型对不同限速环节判断的准确性及其合理性.采用分段法可以确定出不同控制环节的转换时间点和动力学参数可以普适地用在其他反应过程动力学的研究中.

According to the reduction kinetics characteristics of industrial production of sinter,a new model concerned chemical reduction kinetics and molecular diffusion of the cubic particles in different states of reduction process w as established on the basis of mass transfer of metallurgy transport principle and the basic principle of the chemical reduction.The sectional stepw ise method w as adopted to study the reaction kinetics of the sinter particles reduced by CO.Then the sw itch point of the different rate-limiting steps and the relevant kinetic parameters w ere obtained.Finally,the relationship betw een the kinetic parameters and temperature w as determined.Moreover,the accuracy of distinguishing different rate-limiting steps of this model and its rationality w as verified through the observation of the microstructure evolution during the reduction process of sinter ores.Therefore,the sectional stepw ise method determined the sw itch point of different rate-limiting steps and the relevant kinetic parameters,w hich can be universally used in the investigations of dynamics of other reaction process.