Abstract: In order to obtain corundum refractories with good thermal shock resistance and long service life,the samples were prepared using white corundum (5-3,3-1,≤1,and ≤0.044 mm) as the main raw material,and chromium (≤0.074 mm) as the additive.Effects of the chromium addition (0,1%,3%,and 5%,by mass) on the physical properties,the thermal shock resistance and the slag corrosion resistance were studied.The results show that:(1)with the chromium addition increasing,the bulk density,the compressive strength and the thermal shock resistance of the samples increase and reach the maximum with 3% chromium addition;(2)the oxidation of chromium at high temperatures produces Cr₂O₃,causing volume expansion,filling partial pores among corundum particles in the sample,and increasing the bulk density;the generated Cr₂O₃ reacts with Al₂O₃ to form alumina chromia solid solution,improving the bonding strength between the matrix and the corundum particles;(3)the addition of chromium can also effectively inhibit the immersion of slag into the refractories and reduce the corrosion depth;when the addition increases from 0 to 3%,the corrosion depth decreases from 6.4 mm to 4.1 mm.

Key words: corundum refractories, chromium, alumina-chromia solid solution, microstructure, slag corrosion resistance

摘要： 为了获得抗热震性好、使用寿命长的刚玉质耐火材料,以粒度为5~3、3~1、≤1、≤0.044 mm的白刚玉为主要原料,金属铬(≤0.074 mm)为添加剂制备刚玉质耐火材料。研究了金属铬添加量(质量分数分别为0、1%、3%和5%)对刚玉质耐火材料物理性能、抗热震性以及抗渣侵蚀性能的影响。结果表明:1)随着金属铬加入量的增加,试样的体积密度、耐压强度及抗热震性能增加,当金属铬加入量(w)为3%时达到最大值。2)金属铬在高温下氧化生成Cr₂O₃产生体积膨胀,填充了试样中刚玉颗粒间的部分气孔,提高了试样的体积密度;生成的Cr₂O₃与Al₂O₃发生固溶反应形成铝铬固溶体,提高了基质与刚玉颗粒间的结合强度。3)加入金属铬还可以有效抑制熔渣向耐火材料内部的侵入,有效减少熔渣侵蚀深度。当加入量由0增加至3%(w)时,侵蚀深度由6.4 mm减小至4.1 mm。

关键词: 刚玉质耐火材料, 金属铬, 铝铬固溶体, 微观结构, 抗渣侵蚀性能