铝、硅添加对方镁石-铝镁尖晶石质免烧耐火材料性能的影响

采用电熔镁砂和电熔尖晶石为主要原料,以葡萄糖和水合硫酸铝为复合结合剂,以金属铝粉和单质硅为添加剂,制备方镁石-铝镁尖晶石质免烧耐火材料,研究了不同热处理温度下铝加入量及硅铝复合添加对耐火材料显微结构、烧结性能及力学性能的影响。结果表明,随着铝粉加入量的增加,方镁石-铝镁尖晶石免烧耐火材料经不同温度处理后的线膨胀率、常温抗折强度和常温耐压强度增加,并且高温抗折强度也不断提高;另外,金属铝和单质硅的添加会引起耐火材料在升温过程中的增重并减少材料的体积膨胀,从而进一步提高材料的常温力学性能。

Effect of Al and Si addition on the properties of unfired periclase-spinel refractory

With fused magnesia and fused spinel as main raw materials, glucose and hydrated aluminum sulfate as composite binder, and metallic aluminum and silicon powder as additives, the unfired periclase-spinel refractories were prepared. The effects of aluminum addition amount as well as co-addition of aluminium and silicon on the microstructure, sintering properties and mechanical properties of the as-prepared refractories at different treating temperatures were investigated. The results show that with the increase of the addition amount of aluminium powder, the linear expansion rate, cold crushing strength and cold bending strength of the refractories increase accordingly, along with the enhancement of high temperature bending strength. Meanwhile, the composite addition of aluminium and silicon causes the weight gain of the refractory during heating process, and also effectively reduces its volume expansion; as a result, the mechanical properties of the refractories at room temperature are further improved.