复吹转炉深脱磷技术在国内的应用与进展

Application and development of deep dephosphorization technology in top and bottom combination blown converters

国内钢厂采用复吹转炉深脱磷主要工艺有单渣法(冶炼低碳钢)、单炉新双渣法、两炉双联法。采用的前期脱磷工艺参数是:适当降低供氧强度、大幅度提高底吹供气强度、适当延长脱磷期时间、熔池温度控制在磷、碳氧化反应转化温度之下、控制适当的炉渣碱度和T.Fe含量,复吹转炉的脱磷效果明显。冶炼低碳钢时,终点钢水w(P)可控制到0.004 8%～0.008 0%,冶炼中、高碳钢时,终点钢水w(P)可控制到0.01%的水平,达到深脱磷的目的。

Main dephosphorization processes with top and bottom combination blown converters in domestic steel plants involve singleslag process （for low carbon steel）, new doubleslag process in one converter, duplux process in two converters. The parameters for dephosphorization are suitably lowering oxygen intensity, largely increasing bottom gas intensity, properly prolonging dephosphorization time, controlling temperature below the conversion temperature of phosphorus and carbon oxidation reactions, and suitably controlling basicity and T.Fe content in slag. The mass fraction of phosphorus range of 0.004 8 %～0.008 0 %or 0.01 %at end point can be achieved for low carbon or medium and high carbon steel, respectively. Obvious and deep dephosphorization results in top and bottom combination blown converters can be achieved.