转炉钢渣热态改性对镁质耐火材料的侵蚀行为

摘要

以镁质坩埚为试验容器,配制碱度分别为1.2、1.5、1.7、1.9、2.2、2.4的改性钢渣并放置于坩埚中,以10℃·min-的速率升温至1 570℃并保温30 min加热熔化.研究了热态改性钢渣对镁质坩埚的侵蚀,并采用光学显微镜、SEM、EDS和XRD进一步分析了侵蚀行为.分析表明:改性钢渣对镁质耐火材料的侵蚀反应主要在熔渣-坩埚界面处进行,熔渣碱度≤1.5时耐火材料侵蚀加重；由于钢渣中铁离子渗透进方镁石晶体内,形成弥散分布的颗粒状富FeO固溶体和含FeO方镁石基质相,这两种物相受内部FeO、MgO质量比和钢渣中Al2O3含量的影响,选择性地同渣中不同化学组分进行反应而脱落溶解至钢渣中.%Six kinds of modified BOF slag with varied basicities (1. 2,1. 5,1.7,1. 9,2. 2,2.4,respectively) were prepared,put in six separate magnesia crucibles,heated to 1 570 ℃at 10℃· min-1 holding for 30 min. The corrosion of the hot modified slags to the magnesia crucible was analyzed with optical microscope ,SEM,EDS and XRD. Analysis shows that the corrosion reaction of magnesia crucible by the modified slags mainly occurs in the slag-crucible interface,and when the basicity of liquid slag is ≤1.5 the corrosion of crucible gets severe;Fe ions in liquid slag penetrate into the periclase crystals forming the dispersed granular FeO-rich solid solution and FeO-containing periclase matrix phase,and they selectively react with different components of liquid slag and dissolve in the slag affected by their mass ratio of FeO to MgO and the AI2O3 content in liquid slag.