Al2O3和Na2O对高磷铁水脱磷的影响

 在1350℃，采用无氟CaO-FetO-SiO2渣系，以少量Na2O和Al2O3作助熔剂，对磷含量0.42%(质量分数，下同)的铁水进行了脱磷热力学试验。 结果表明：Na2O和Al2O3含量分别为0.7%~3.1%和2.5%~7.9%时，脱磷率为81.4%~90.7%，lgLP为1.50~1.92，lgγP2O5在-15.6~-16.6之间，lgCP为19.9~20.5。脱磷率、lgLP和lgCP 随Na2O含量的增加而增加。lgγP2O5随Na2O含量的增加而降低。Al2O3对脱磷效果的影响与Na2O正好相反。采用半球点法对CaO-Fe2O3-Na2O-Al2O3无氟脱磷剂进行了熔点测试。 发现以Na2O和Al2O3作助熔剂均可使脱磷剂熔点降至1200℃以下，满足高磷铁水转炉脱磷温度要求。

Effect of Al2O3 and Na2O on Dephosphorization of High Phosphorus Hot Metal

Dephosphorization thermodynamics of high phosphorus hot metal (0.42%) at 1350℃ was investigated by using CaO-FetO-SiO2 slags, which contained small amounts of Na2O and Al2O3. When the content of Na2O and Al2O3 is 0.7%-3.1% and 2.5%-7.9%, respectively. η, lgLP, lgγP2O5 and lgCP are in the range of 81.4%-90.7%, 1.50-1.92, -15.6--16.6 and 19.9-20.5, respectively. η, lgLP and lgCP increases with the increasing of Na2O content. lgγP2O5 decreases with the increasing of Na2O content. However, Al2O3 content shows an opposite effect on dephosphorization. Melting temperatures of CaF2-free CaO-Fe2O3-Na2O-Al2O3 dephosphorization slag were measured by using hemisphere method. The results show that both Na2O and Al2O3 could decrease melting temperature to ≤1200℃ to meet the requirement of high phosphorus hot metal dephosphorization in converter.