Abstract:

Based on the proposal of “micro-pored aggregates and dense-packed matrixes” and the particle dense packing theory,the Dinger-Funk Equation was modified to establish a prediction model of matrix packing density for lightweight refractories.Lightweight alumina magnesia castables were prepared using micro-pore corundum,bauxite and magnesia as starting materials.The micro-pore corundum used has low apparent density,high closed porosity,low thermal conductivity (20%-50% lower than the common corundum),similar slag resistance of the common corundum and micro- or nano-sized intracrystalline pores.The results show that the lightweight alumina magnesia castables not only have good thermal shock resistance and low thermal conductivity,but also have the same slag resistance as the common alumina magnesia castables.The onsite application shows that the service life of the alumina magnesia precast blocks for the ladle working lining prepared with the microporous corundum as aggregates are better than that of the current materials with the same conditions.

Key words: lightweight, microporous aggregates, dense-packed matrix, alumina-magnesia castables

摘要：

基于“骨料微孔化、基质紧密化”的研究思路,采用显气孔率低、闭口气孔率高、热导率比普通耐火材料低20%~50%、抗渣性能与普通原料相当的具有微纳米尺度晶内气孔的微孔刚玉和矾土以及镁砂为原料,根据颗粒紧密堆积理论,对Dinger-Funk方程进行修正,建立轻量耐火材料基质堆积密度预测模型,制备了轻量铝镁浇注料。结果表明:此轻量铝镁浇注料不仅抗热震性好,热导率小,而且抗渣性能与普通铝镁浇注料相当。实际应用表明,采用微孔刚玉为骨料制备的钢包工作层用Al₂O₃-MgO质预制块使用寿命在同等条件下均优于现行材料。

关键词: 轻量化, 微孔骨料, 基质紧密化, 铝镁浇注料