Abstract: The tested hot metal containing 0.40% P is made from commercial iron, phosphoric iron and ferrous sulfide with slagging forming material lime : fluorite =9 ：1 and slagging forming material : metal = 1 ：50, and melted at 1600℃. by a tube-type electric resistance furnace. The effect of the microstructure of lime-specific surface area (1.05~4.75 m²/ g) , average pore diameter (605~ 404 nm) , pore volume (0.23~0.78 mL/g) and bulk density (0.80~3.10 g/cm³), and the activity of lime (298~350 mL) on dephosphorization of hot metal has been studied by field emission SEM and automatic pressure mercury device. Results show that with increasing the activity of lime the dephosphorization ratio increases gradually ； with increasing the specific surface area, average pore diameter, pore volume and bulk density, the dephosphorization ratio of metal increases first and then decreases ； with lime specific surface area 2.5 m²/g, average pore diameter 750~850 nm, pore volume 0.45 ~0.55 mL/g and bulk density 2.0 g/cm³, the dephosphorization ratio of metal is highest, it is up to 63.0%.

Key words: Lime, Activity, Microscopic Structure, Dephosphorization Rate

摘要： 通过管式电阻炉,用工业铁块、磷铁和硫化亚铁配制0.40%P试验用铁水,造渣剂石灰:萤石=9:1,造渣剂与铁水的比例为1:50,熔融温度1600℃。采用场发射扫描电镜和全自动压汞仪研究了石灰的微观结构-比表面积（1.05~4.75 m²/g）、平均孔径（605~1404 nm）、孔容积（0.23~0.78 mL/g）、体积密度（0.80~3.10 g/cm³）和活性度（298~350 mL）对铁水脱磷的影响。结果表明,随着石灰活性度的增加,铁水脱磷率逐渐增加;随着比表面积、平均孔径、孔容积和体积密度的增加铁水的脱磷率均先增加后降低,当石灰比表面积2.5 m²/g,平均孔径750~850 nm,孔容积0.45~0.55 mL/g,体积密度2.0 g/cm³时铁水的脱磷率达到最好,其铁水脱磷率达到63.0%。

关键词: 石灰, 活性度, 微观结构, 脱磷率