废镁铬砖在镁质浇注料中的应用

Application of reused magnesia chrome bricks in magnesia based castable

将宝钢RH炉废镁铬砖和电熔镁砂均破碎成5～3mm、3～1mm、<1mm的粒度,添加3%的粒度<1μm的二氧化硅微粉,按照浇注料的生产工艺制备了镁铬浇注料,研究了废镁铬砖在镁质浇注料中的应用。结果表明:浇注料悬浮液的碱度可控制在pH值=7～9,用0.15%(质量分数,下同)的六偏磷酸钠为减水剂时,该悬浮液ζ电位的绝对值最大,悬浮液最稳定,分散性也最好。随着废镁铬砖加入量的降低,烘干、中温和高温处理后的耐压强度、抗折强度、体积密度均逐渐增大。废镁铬料添加量为36%的试样FM3的性能指标均达到了纯镁质浇注料M4的;试样FM3对渣的抗熔蚀性能要优于试样M4的。

The magnesia chrome castable was produced by using used RH magnesia chrome bricks of Baosteel and fused magnesite crashed into particles with size of 5 -3 mm,3 -1 mm and 〈1 mm,and adding 3% silica fume with size 〈1 μm. The application of reused magnesia chrome bricks in magnesia based castable was studied. The research implied：while controlling the pH value of castable suspension at 7 - 9 and using 0. 15% SliP as dispersant,the absolute ξ potential value reached the highest, suspension stability and dispersion were the best. By reducing the addition of reused magnesia chrome bricks.the crushing strength, MOR and bulk density became higher after drying and firing at medium and high temperature. The specimen FM3 with addition of 36% reused bricks performed similarly as pure magnesia castable M4,and has even better slag penetration resistance than specimen M4.