镁钙质耐火材料脱硫反应动力学研究  

Dynamic study on desulphurization reaction of MgO-CaO refractories

作　　者：田琳[1] 陈树江[1] 张玲鞍 

机构地区：[1]山科技大学材料科学与工程学院,鞍山114044

出　　处：《耐火材料》2006年第5期358-361,共4页Refractories

摘　　要：将镁钙砖（w（MgO）=75.13%,w（CaO）=22.09%）制成坩埚烘干,将配好的钢样放于镁钙坩埚内,置于高温管式炉中,同时通氩气保护,升温至1600 ℃恒温5～70 min,每隔5 min取样,利用偏光显微镜和直读光谱仪分析镁钙坩埚的显微结构变化及钢液中[S]含量的变化,并建立钢液脱硫反应动力学模型,研究1600 ℃时镁钙耐火材料对钢液脱硫的动力学机理.结果表明：在1600 ℃下,反应时间为45 min时,脱硫效果最好,脱硫率可达到70.12%,但超过45 min,脱硫率降低,出现“回硫”现象;脱硫反应初期为界面化学控制过程,后期是扩散控制过程;计算得到化学反应速率常数Kr=5.50×10^-4 m·s^-1,扩散系数Deff=1.33×10^-8 m2·s^-1.The MgO -CaO brick（w（MgO） =75. 13%, w（CaO） =22.09% ） was made into a crucible and dried. A prepared steel specimen was placed in the crucible and both were fired in a high temperature tube furnace in argon protective atmosphere. The temperature was raised to 1600 ℃ and then maintained for 5 - 70 minutes,the specimen was taken out every 5 min. The microstructure of the crucible and [ S] content in the molten steel were analyzed by polarizing microscope and direct-reading spectrograph. A dynamic model of the desulphurization reaction of molten steel was made and the desulphurization dynamic mechanism of the magnesia -calcia refractories at 1600 ℃ was studied. The result indicated that the best effect of desulphurization with rate of 70.12% appeared when reaction lasted 45 min at 1600 ℃;However,when the reaction lasted over 45 min,the desulphurization rate decreased and ＂resulphurization＂ happened. The previous stage of desulphurization process was controlled by interface chemical reaction mechanics and the posterior stage was controlled by diffusion mechanics. The chemical reaction rate constant, Kr =5.50 x 10^-4 m · s^-1 and the diffusion coefficient Deff =1. 33 × 10^-8 m^2 · s^-1

关 键 词：镁钙耐火材料 脱硫 动力学 钢液 

分 类 号：TQ175.713[化学工程—硅酸盐工业]