不同喷吹煤种对除尘灰中未燃煤粉影响

国内某钢厂一座高炉现阶段喷煤量为160 kg左右，对其使用晨旭煤做喷吹煤时和正赫煤做喷吹煤时的2个阶段的高炉除尘灰（重力除尘灰和布袋除尘灰）进行了研究。高炉的重力灰和布袋灰的粒度组成和分布表明：重力灰中粒径主要集中在10～110μm，小于110μm颗粒占96%左右，大于74μm，小于297μm的颗粒约占60%；布袋灰的粒度分布图大致集中在3～30μm，小于20μm颗粒占到80%以上。通过岩相显微分析得到了重力灰和布袋灰中的各显微组分的面积分数，并根据除尘灰中未燃煤粉和焦粉的消耗程度，结合化学分析和岩相显微分析结果计算，得到了该高炉喷吹不同煤种时除尘灰中未燃煤粉所占的百分比。最后，初步得出喷吹不同煤种对高炉除尘灰中未燃煤粉质量分数的影响，即与晨旭煤相比，正赫煤的反应性和燃烧性都较好，喷吹期间，炉尘中产生的未燃煤粉较少，煤粉利用率较高。同时也表明，实验室热重法测得的燃烧性和反应性可以作为评价煤粉最终利用率的2个重要参数，为钢厂实际生产中的喷煤评价和煤种选择提供了可靠的新方法。

Different coal injection on unconsumed pulverized coal in BF dust

The amount of injected coal was approximately 160 kg for a BF in a domestic steel mills recently,a study on BF dust(gravitational dust and cloth-bag dust)has been carried on when the Chenxu coal and the Zhenghe coal were in-jected in different period.The particle composition and the distribution of particles in BF dust showed that the diameter of particles in gravitational dust was mainly among 10μm and 110μm,96%particles were smaller than 110μm;while 60%particles in gravitational dust lied among 74 to 297μm.The particles of cloth-bag dust mainly scattered from 3 to 30μm,80%particles were smaller than 20μm. The area ratio of different microscopic structure in BF dust has been giv-en out according to petrographical microanalysis. Based on the utilization degree of the unconsumed pulverized coal and the coke,the ratio of unconsumed pulverized coal of different coals in the current BF was determined according to the chemical and petrographical analysis. Finally,the influence of different coal injection on the amount of unconsumed pul-verized coal was evaluated. It could be preliminary concluded that the reactivity and the combustibility for both coals were well,while the content of unconsumed pulverized coal in BF dust was smaller when injecting Zhenghe coal into BF. And it is reliabe to use the combustibility and reactivity-which can be obtained by laboratory thermogravimetric method-as two key indexs for evaluating the utilization of coal in actual plant production.