Al2 O3和二元碱度对炼钢炉渣中磷酸盐富集机理的综合影响

以六元CaO-SiO2-FeO-P2 O5-Fe2 O3-Al2 O3炼钢渣系为研究对象,结合热力学计算和实验检测,分析( Al2 O3)和二元碱度B综合变化对该六元渣系中磷酸盐富集行为的影响.结果表明：炼钢炉渣中生成游离C2 S含量对磷酸盐富集相nC2 S-C3 P内的( P2 O5)至关重要.该渣系中增加SiO2会降低总的C2 S生成量,增加Al2 O3可促进钙铝黄长石C2 AS相生成,降低游离C2 S ( f-C2 S)的量,进而影响磷酸盐的富集.六元CaO-SiO2-FeO-P2 O5-Fe2 O3-Al2 O3炼钢炉渣获得较好磷酸盐富集程度,渣中二元碱度B和Al2O3含量需满足的耦合关系为：(%Al2O3)=-27.70+21.62B,(Al2O3)<20.0%,B>1.3.

Comprehensive effect of Al2 O3 content and binary basicity on the enrichment mechanism of phosphates in quenched steelmaking slags

A comprehensive effect of Al2 O3 content and binary basicity B on the enrichment behavior of phosphates in rapidly quenched CaO-SiO2-FeO-P2 O5- Fe2 O3- Al2 O3 steelmaking slags was investigated through thermodynamic calculations and experi-mental determination. It is found that the determined mass percentage of P2 O5 in the phosphate-enriched phase nC2 S-C3 P depends on the forming of free C2 S in the steelmaking slags and increasing the SiO2 content can result in an obviously decreasing tendency of formed C2 S. Adding Al2 O3 as a dilute agent for decreasing the viscosity and melting point of the steelmaking slags can be easily bond-ed with free C2 S to form a gehlenite ( C2 AS) solid solution. Thus, adding Al2 O3 in the steelmaking slags can decrease the amount of free C2 S in the steelmaking slags, which affects phosphate enrichment. In order to obtain a greater phosphate enrichment in the steel-making slags, a coupling relationship between the binary basicity B and the mass percentage of Al2 O3 in the initial steelmaking slags should be kept as (%Al2O3) = -27. 70+21. 62B under the conditions of (Al2O3) <20. 0% and the binary basicity B>1. 3.