渣相组分对高炉炉缸死焦堆滞留率的影响

Effect of slag composition on holdup rate of deadman in blast furnace hearth

为明确高炉炉渣组分对死焦堆中炉渣静态滞留率的影响,采用自行设计的炉渣穿焦试验装置模拟高炉炉渣穿过炉缸死焦堆的过程,探究不同二元碱度(w(CaO)/w(SiO2))、镁铝比(w(MgO)/w(Al2O3))对炉渣滞留率的影响。试验结果表明,随着碱度的增加,炉渣穿过焦炭层的能力增强,滞留率降低;当炉渣镁铝比较低时,炉渣滞留率较高,当镁铝比为0.50~0.55时,滞留率出现最小值,当镁铝比较高时,由于渣焦间润湿性变好,"液桥"间炉渣滞留量增大,滞留率存在上升趋势;渣焦间润湿性较差。炉渣穿过焦炭层的过程主要为物理传输过程,但炉渣仍存在着向焦炭内部渗入的现象,渣焦界面发生反应生成SiC,该反应产物可改善渣焦界面润湿性。

In order to investigate the influence of blast furnace slag composition on the static holdup rate of slag in the deadman,a self-designed slag penetration coke experimental device was used to simulate the process of blast furnace slag flowing through the deadman in the hearth.The effect of basicity(w(CaO)/w(SiO2))and w(MgO)/w(Al2O3)on the static holdup rate of slag were also studied.The results show that as the basicity increasing,the ability of the slag dripping through the packed coke beds increases and the static holdup rate decreases.When the w(MgO)/w(Al2O3)is relatively low,the static holdup rate is high.When the w(MgO)/w(Al2O3)ranges from 0.5 to 0.55,the static holdup rate reaches its minimum.When the w(MgO)/w(Al2O3)is relatively high,the static holdup of"liquid bridges"becomes larger due to the better wettability between slag and coke,and the static holdup rate increases to a certain extent.The process of slag passing through the coke layer is mainly aphysical transmission process due to the poor wettability between coke and slag.However,the SiC phase produced on the coke/slag interface as a result of the penetration of slag through the pores of the coke can improve the wettability.