钢包渣对轻质方镁石–镁铝尖晶石耐火材料的侵蚀机理

Corrosion Mechanism of Ladle Slag to Lightweight Periclase–MA Spinel Refractories

采用多孔方镁石–镁铝尖晶石陶瓷骨料、镁铝尖晶石细粉、镁砂细粉和刚玉细粉等原料制备了尖晶石细粉含量不同的轻质方镁石–尖晶石耐火材料。以钢包渣为侵蚀介质、采用静态坩埚法对材料进行了侵蚀实验,并借助扫描电子显微镜、能谱仪和Fact Sage？热化学软件研究了镁铝尖晶石细粉含量对轻质材料抗渣性能的影响。结果表明：镁铝尖晶石比方镁石具有更强的固溶Fe2O3和MnO的能力,能通过吸收渗透渣中Fe2O3和MnO增加渗透渣黏度,且当尖晶石细粉含量从0%（质量分数）逐步增大到26.5%时,材料气孔的平均孔径逐渐减小,这些有利于提高抗渣渗透性能;尽管镁铝尖晶石比方镁石更易于溶入钢包渣,但因增加尖晶石含量增强的抗渗透能力,减小了材料与渣的接触面积,减缓了尖晶石向渣中的溶解速率,进而提高了材料的抗渣侵蚀性能。随着尖晶石细粉含量从0%、8.5%、16.3%逐步增加到26.5%,轻质方镁石–尖晶石耐火材料的抗渣性能也逐步提高。

Four lightweight periclase--MA spinel refractories containing different spinel powder contents were fabricated using porous periclase--MA spinel ceramics aggregates, spinel powder, magnesia powder and corundum powder as raw materials. The slag resistances of periclase--MA spinel refractories were conducted via the static crucible tests by ladle slag. The effect of spinel powder content on the slag resistances of the lightweight periclase-MA spinel refractories was investigated using scanning electron microscopy, energy dispersive spectroscopy and FactSage software. The results show that compared to periclase, the spinel has a higher ability of taking up Fe2O3 and MnO from the slag, thus increasing the viscosity of the penetrated slag. The average pore size of matrices of castables gradually decreases when the spinel powder content increases from 0% （in mass fraction） to 26.5%, which is beneficial to improve the penetration resistance. Although the spinel dissolves more easily into slag than periclase, the penetration resistance enhances as the spinel content increases, decreasing the contact area between refractory and slag and the dissolution rate of spinel into slag, and thus improving the corrosion resistance. The corrosion resistance can be improved when the spinel content in lightweight castables is increased from 0% to 8.5%, 16.3% and 26.5%, respectively.