高炉高球比条件下炉料颗粒偏析行为及其优化

Burden particle segregation behavior and its optimization under blast furnace operation with high pellet charging ratio

提高入炉球团矿比例是高炉低碳冶炼的重要手段,由于球团矿滚动性强,在高炉布料过程中会存在炉料粒度偏析的问题,因此优化布料制度、降低炉料粒度偏析,对改善高炉上部气流分布具有重要意义。为此,通过建立物理模型,研究球团矿配比、矿石批重和溜槽倾角对高炉布料偏析的影响,结果表明,提高球团矿配比能够降低炉料的粒径差,改善炉料粒度偏析情况。基于试验结果建立了炉料粒度偏析指数预测的多元回归模型,发现炉料粒度偏析指数随着溜槽倾角的增加逐渐增大,在溜槽倾角大于32°后炉料粒度偏析指数的增幅变小;炉料粒度偏析指数随着矿石批重的增加呈现先增大后减小的变化趋势。在球团矿配比固定时,采用大批重小角度溜槽倾角或者小批重大角度溜槽倾角可以有效减小炉料粒度偏析。研究结果可以为高炉采用高比例球团矿冶炼时优化调整装料制度提供参考。

Increasing the proportion of pellets in blast furnace is an important means of low carbon smelting in blast furnace.Because of the strong rolling property of pellets,there will be the problem of particle size segregation in the charging process of blast furnace.Therefore,optimizing the distribution system and reducing the segregation of charge size are of great significance to improve the airflow distribution in the upper part of blast furnace.A physical model was established to study the effects of pellet ratio,ore batch weight and chute angle on the segregation of blast furnace charge.The results show that increasing pellet ratio can reduce particle size difference and improve particle size segregation of charge.Based on the experimental results,multiple regression model was established for predicting segregation index of charge particle size.It is found that the segregation index of charge particle size increases gradually with the increase of chute angle.When the chute angle is greater than 32°,the increase range of segregation index becomes smaller.The segregation index of charge particle size increases first and then decreases with the increase of ore batch weight.When the proportion of pellets is fixed,large batch weight and small chute angles,or small batch weight and large angle chute angles can effectively reduce the particle size segregation of the charge.The research results can provide reference for optimizing and adjusting the charging regulations of blast furnace melting with high proportion pellet.