Abstract:

In order to study the effect of the density of sintered alumina aggregate on properties of corundum-spinel castables,sintered corundum with different densities was prepared using industrial Al₂O₃ powder as the raw material,which was further used as aggregates to prepare corundum-spinel castables.The density,the strength,the thermal shock resistance and the slag resistance of the corundum-spinel castables were researched.The results show that:(1)the density and the grain size of the sintered corundum gradually increase with the increase of the density of spheroidized body of industrial Al₂O₃ powder;(2)with the increase of the sintered alumina aggregate density,the water demand of the corundum-spinel castables decreases;the density and the cold strength of the castables increase after firing,and the thermal shock resistance worsens;for the slag corrosion resistance,the castables are similar except the one with bulk density of 3.45 g·cm^-3 is obviously poor;(3)overall,the optimal bulk density of the sintered alumina aggregate is 3.51-3.55 g·cm^-3.Therefore,it cannot be unilaterally considered that the higher the bulk density of the sintered corundum,the better the properties of the castables;over high bulk density will lead to poor thermal shock resistance of refractories and increase the unit weight of refractories.

Key words: sintered corundum, density, corundum-spinel castable, thermal shock resistance, slag corrosion resistance

摘要：

为了研究烧结刚玉骨料致密度对刚玉-尖晶石浇注料性能的影响,首先以工业Al₂O₃粉为原料制备不同致密度的烧结刚玉;然后以不同致密度的烧结刚玉为骨料制备刚玉-尖晶石浇注料,并研究了刚玉-尖晶石浇注料的致密度、强度、抗热震性和抗渣性等性能。结果发现:1)随着工业氧化铝粉成球坯体致密度的增大,制成的烧结刚玉的致密度和晶粒尺寸逐渐增大。2)随着烧结刚玉骨料致密度的增大,刚玉-尖晶石浇注料的需水性减小;烧后浇注料的致密度和常温强度增大,抗热震性变差。抗渣侵蚀性除采用体积密度为3.45 g·cm^-3的烧结刚玉骨料的浇注料明显较差外,其他浇注料的差别不大。3)综合考虑,烧结刚玉骨料的体积密度以3.51~3.55 g·cm^-3为佳。因此,不能片面地认为烧结刚玉的体积密度越大越好;过高的体积密度会导致耐火材料抗热震性能变差,并增加耐火材料单重。

关键词: 烧结刚玉, 致密度, 刚玉-尖晶石浇注料, 抗热震性, 抗渣性