150t LF-VD炉渣线用优质镁碳砖的研制

Development of MgO-C brick for slag line of 150 t LF-VD furnace

针对宝钢 15 0tLF -VD炉的操作条件 ,对渣线用镁碳砖进行了研究。结果表明 :1)砖的体积密度和 175 0℃ ,3h埋炭处理后的强度随镁砂细粉含量的增加而降低 ;2 )在 1～ 5mm的临界尺寸范围内 ,4mm的临界粒度最有利于提高镁碳砖的抗侵蚀性 ;3)硅粉和CaZrO3的加入都不利于镁碳砖的抗侵蚀性 ,且随着CaZrO3含量增加 ,抗侵蚀性变差 ;4 )添加特殊抗氧化剂的镁碳砖的抗氧化性和抗侵蚀性显著提高。研制的成本较低、性能非常优良的镁碳砖应用于宝钢 15 0tLF -VD炉渣线 ,与以前镁碳砖相比 ,抗侵蚀性提高 2 0 %以上 ,使用寿命达 4 6炉次 ,显著优于进口产品。

Abstract:MgO-C brick for slag line of 150t LF-VD furnace was studied in accordance with the operation condition of the furnace.The results show that :(1)the bulk density and strength treated at 1750 ℃ for 3 h (covered with carbon) of the brick decrease as magnesia fine grain content increases;(2) in the range of 1～5 mm of the critical particle size,the optimum critical particle size of magnesia for the best corrosion resistance of the brick is 4 mm;(3)CaZrO 3 and Si powder added make the corrosion resistance of the brick bad,and more CaZrO 3 addition makes the corrosion resistance worse;and (4) the special antioxidant can enhance both the oxidation resistance and corrosion resistance remarkably.The developed bricks were trial used in the slag line of 150 t LF-VD furnace in Baosteel achieving 46 heats.The corrosion resistance of the brick is 1.2 times of the original one and its corrosion resistance was also better than the imported one.