基于里斯特操作线解析有害元素对高炉焦比的影响

Effect of harmful elements on the coke ratio of blast furnace based on the Rist operating diagram

  • 摘要: 分析了有害元素在高炉内的循环行为,结合高炉实际生产参数,运用里斯特操作线进行计算,揭示了有害元素对焦比的影响规律,建立了焦比与有害元素入炉负荷和循环富集倍数之间的定量关系.计算结果表明:有害元素在高炉内"还原-氧化-再还原"的循环过程会将高温区的CO转移到低温区,降低煤气利用率,同时消耗了高温区大量热量,从而使焦比升高.不同有害元素的影响程度不同.有害元素循环富集倍数对焦比影响的强弱顺序为:Na > K > Zn,有害元素入炉负荷对焦比影响的强弱顺序为:Zn > Na > K.进一步的分析表明,Na、Zn对高炉焦比的影响大于K.但考虑到K对焦炭劣化的作用更明显,故要严格控制K、Na、Zn的入炉负荷.基于上述计算得到的定量关系,利用高炉不同有害元素入炉负荷以及焦比进行曲线拟合,预测高炉有害元素的循环富集倍数.曲线拟合结果与高炉解剖实验结果相吻合.

     

    Abstract: The adverse effects of harmful elements on blast furnace life and production have been adequately researched; however, studies of the effects on the energy consumption of blast furnace are few. In this study, the circulation and accumulation of harmful elements in a blast furnace were analyzed. By combining the actual production parameters of a blast furnace and the Rist operating diagram, the effect of the harmful elements on the coke ratio was revealed and the quantitative relationship between the coke ratio and the loads and accumulation times of harmful elements was established. The calculation results show that the harmful elements cycle of "reduction-oxidation-re-reduction" in the blast furnace can transfer the CO from the high-temperature zone to the low-temperature zone, and consume a lot of heat in the high-temperature zone. This can decrease gas utilization and increase heat consumption in the hightemperature zone, consequently increasing the coke ratio. Each harmful element affects the coke ratio differently. Considering their accumulation times and loads, the harmful elements affect the coke ratio in the following orders:Na > K > Zn and Zn > Na > K, respectively. Further analysis shows that the effect of Na and Zn on the coke ratio is greater than that of K. However, considering the effect of K on coke deterioration is more significant, it is necessary to strictly control the load of K, Na, and Zn. Based on the quantitative relationship obtained by the above calculation process, curve fitting is carried out using the loads of harmful elements and coke ratio of blast furnace to predict the harmful elements accumulation times in the blast furnace. The curve fitting results are consistent with the blast furnace dissection experiment results.

     

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