钢包用矾土尖晶石浇注料的抗渣侵蚀机理研究

The Mechanism of Corrosion Resistance of Bauxite-spinel Castable for Steel Ladle

利用XRD,SEM等分析手段对用后的以铝酸钙水泥和MgO-SiO_2-H_2O为复合结合剂的钢包矾土尖晶石浇注料进行表征,并对其抗渣侵蚀机理进行研究。分析结果表明:铝酸钙水泥及MgO-SiO_2-H_2O体系的复合结合剂在高温下与基质中矾土细粉、α-Al_2O_3等反应生成非晶态熔融相,使得基质的致密度提高,抑制了钢包渣向其内部的渗透;预合成及原位反应生成的镁铝尖晶石吸附渣中的Fe^(2+),导致渣中Fe^(2+)的浓度降低,粘度提高,最终渣的成分转变为硅含量较高的CaO-SiO_2-Al2O_3渣;矾土原料晶界处杂质在高温下生成的非晶态熔融相迁移至基质,其富含的TiO_2与CaO-SiO_2-Al_2O_3。渣中的CaO反应生成稳定的钙钛矿,降低了渣中CaO的含量,渣的粘度进一步提高,抑制了渣向矾土尖晶石浇注料内部的持续渗透和扩散。

The mechanism of corrosion resistance of ladle used bauxite--spinel bonded by compos- ite binder of calcium aluminate cement and MgO--SiO2- H2O system was investigated by using XRD and SEM, The results show that the composite binder of calcium aluminate cement and MgO--SiO2 -- H2O system reacts with bauxite powder and α-- Al2 O3 in the matrix and then generates amorphous melting phase which enhances the density of the substrate, as a result, slag infiltration is controlled; preformed and in suit spinel absorb FeO from the stag, result in enrichment of silica in the Slag, de- creasing the density of Fe2＋ and increasing the viscosity there; Impurities in the bauxite grain bounda- ry generates amorpahous melting phase at high temperature which will transfer to the matrix. Titani- um oxide consume CaO from the silica rich CaO--SiO2- Al2O3 slag and generates perovskite, the slag viscosity is increased which restrains the consecutive infiltration of slag towards bauxite- spinel castable.