转炉泡沫渣气泡分布特点及形成过程

在转炉留渣-双渣工艺脱磷阶段结束倒渣时,分别使用样勺获取倒渣开始时上部泡沫渣,倒渣结束时下部泡沫渣以及倒渣结束后炉内剩余底部泡沫渣,使用宏观及微观的方法分别分析泡沫渣各部位气泡分布特点。结果表明：气泡平均当量直径,上部>下部>底部;孔隙率,上部>下部>底部。转炉泡沫渣的形成过程为：随着大量CO/CO2气泡进入渣中,气泡之间不断碰撞、合并,上部气泡被下部气泡抬挤且由于气泡本身的浮力作用,气泡不断上升,气泡在上升时由于重力作用,气泡之间渣相在重力作用下析液,气泡的拓扑结构不断发生变化,同时气泡之间不断碰撞、合并,最后形成上部气泡直径大且孔隙率高,下部气泡直径小且孔隙率低的泡沫渣。

Distribution characteristic and formation process of bubbles in foaming slag in a converter

Foaming slags at the top at the beginning of deslaggging, in the lower portion at the end of deslagging, and at the bottom after deslagging were taken with a sample scoop at the end of dephosphorization in the converter slag-remaining and double-slag process. The distribution characteristic of bubbles was analyzed by the macroµ analysis technique. The results indicate that the order of average equivalent diameter of bubbles is the slag at the top > slag in the lower > slag at the bottom, and the order of gas porosity is the slag at the top > slag in the lower > slag at the bottom. The formation process of foaming slags was observed and analyzed. Bubbles collide and coalesce with CO/CO2 moving into the slag. Bubbles in the upper are elevated by bubbles in the lower and the bubbles rises up with buoyancy. The drainage of liquid slag occurs with gravity and the topological structure of bubbles chan-ges. With bubble collision and coalescence, the foaming slag with larger bubbles and higher porosity in the upper and that with smaller bubbles and lower porosity in the lower are formed.