摘要
为实现Al2O3-SiO2质浇注料的轻量化而采用部分轻烧铝矾土骨料,将伽(Al2O3)为71%的铝矾土生料分别经900和1100℃轻烧,破碎分级成5—3、3~1和≤1mm的骨料。在矾土基超低水泥浇注料基础配比中,分别以质量分数15%、30%和45%的轻烧骨料等量取代特级矾土熟料,检测了各项常规性能并借助扫描电镜观察了显微结构。结果表明:随轻烧骨料加入量的增多,浇注料的需水量增加,显气孔率增加,体积密度下降;1350℃烧后的加热永久线变化率呈下降趋势,但即使加入轻烧料高达45%(W)时,仍能保持残余膨胀;烘干后的抗折强度有所下降,但对1000和1350℃烧后抗折强度影响不大,甚至1000℃烧后的强度有所增加;1300℃的高温抗折强度有所降低。对于使用温度在1350℃以下气氛炉用铝硅质浇注料,用900~1100℃轻烧铝矾土骨料部分取代其熟料骨料,可实现浇注料的轻量化。
For the purpose of reducing Al2O3-SiO2 castables' weight by using mild-calcined bauxite aggregate,raw bauxite with 71% (in mass,the same hereinafter) Al2O3 was calcined at 900 and 1100℃, respectively,then crushed into sizes of 5-3 mm, 3-1 mm and under 1 mm as aggregates. They were added into a bauxite based ULC castable as reference to replace special grade bauxite grog as counterparts by 15% ,30% and 45%, respectively. Regular properties of the castables were tested and the microstructure of related samples was observed by SEM. With increased addition of the mild-calcined aggregates,water demand for casting becomes higher,apparent porosity increases and bulk density decreases;positive value of permanent linear change after firing at 1 350 ℃ declines,nevertheless even at as high as 45% addition of the aggregates,residual expansion can still be maintained;CMOR after drying decreases,while the addi- tion has little influence on CMOR after firing at 1 000 and 1 350 ℃,with even enhanced CMOR after firing at 1 000℃;HMOR at ; 300℃ tends to decrease. Weight reduced aluminosilicate castables used for atmospheric furnaces with service temperatures under 1 350 ℃ can be achieved by using 900-1 100 ℃ mild-calcined bauxite aggregates,worth of practical application trails.
出处
《耐火材料》
CAS
北大核心
2014年第1期13-17,共5页
Refractories