铝镁尖晶石对镁质浇注料性能的影响

Effect of Magnesium Aluminate Spinel on the Properties of Magnesia Based Castables

针对镁质浇注料在使用过程中抗渣渗透能力差,易剥落等问题,本实验加入铝镁尖晶石对镁质浇注料进行改性研究。实验分为两部分:先将镁砂细粉、镁质添加剂和铝镁尖晶石细粉等机压成型,进行高温热处理,研究其物相组成和显微结构;然后以电熔镁砂为骨料,电熔镁砂细粉、氧化铝微粉、铝镁尖晶石细粉和镁质添加剂为基质,按骨料:细粉=75∶25进行配制,研究铝镁尖晶石加入量对镁质浇注料性能的影响。结果表明:在镁质材料中引入尖晶石,能促进结构致密化;加入9%的铝镁尖晶石的浇注料试样显气孔率低,线变化率小,体积密度大,强度大,抗渣性能最好,由于镁铝尖晶石生成时体积膨胀,使得材料结构致密化;同时能有效吸收渣中Ca O及Fe Ox等成分,减少渣的渗透作用,从而提高了浇注料的抗渣性能。

Magnesium aluminate spinel was introduced in magnesia based castables to improve the properties such as poor slag penetration resistance and spalling resistance. This experiment included two parts： First,matrix specimens were prepared by mixing appropriate magnesia fines,magnesian additives and magnesium aluminate spinel and then being pressed and fired. Phase composition and microstructure of the matrix specimens were characterized by XRD and SEM. And then magnesia based castable specimens were prepared by using fused magnesia as aggregates,fused magnesia powder,alumina micropowder,spinel powder and magnesian additives as matrix. The ratio of the aggregates to fines is 75∶ 25. The effects of magnesium aluminate spinel addition on the properties of magnesia based castables were investigated. The results showed that the adding of magnesium aluminate spinel to the magnesia based castables led to its densified structure; When 9% magnesium aluminate spinel was added,specimens with low porosity,small liner change ratio,large bulk density,intensity and the best slag resistance were obtained. The reason was magnesium aluminate spinel expanded when generated,which made the material structure denser; At the same time it could effectively absorb the compositions such as Ca O and Fe O in the slag and reduce the slag penetration. Hence,the slag resistance of castables wasimproved.