w(SiO_2)/w(V_2O_3)对含钒炉渣熔化温度及黏度的影响

Effect of w(SiO_2)/w(V_2O_3) on melting and viscosity properties of vanadium slag

为了对转炉提钒冶炼过程含钒炉渣熔化和流动性进行合理的控制,采用半球点法和内旋转黏度法分别测试了含钒炉渣熔化温度和黏度,采用XRD测试了含钒炉渣的物相,并采用综合碱度(BI′)反映渣中酸碱氧化物平衡关系。结果表明,在FeO质量分数一定的条件下,随着w(SiO_2)/w(V_2O_3)增大,综合碱度由BI′>1单调下降至BI′<1,含钒炉渣熔化温度先降低后升高;随着FeO质量分数的增加,熔化温度最低点对应的w(SiO_2)/w(V_2O_3)增大。随着w(SiO_2)/w(V_2O_3)增大,黏度随温度变化的趋势变缓,高温熔融态含钒炉渣黏度增大,低温阶段黏度减小。综合考虑黏度对钢渣界面反应和钒渣流失的影响,FeO质量分数为44%时含钒炉渣w(SiO_2)/w(V_2O_3)应控制为0.7。

To reasonably control the melting and fluidity of vanadium slag during smelting process of vanadium extraction in converter, hemisphere and rotating methods were applied to study the melting temperature and viscosity of vanadium slags respectively. X-ray diffraction analysis was adopted to determine the phases, and the comprehensive basicity BI′ was used to reflect the balance between acid and alkaline oxides. The results showed that the melting temperature of vanadium slags depended on BI′ and w(SiO2)/w(V2O3). For a given FeO mass fraction, BI′ decreased from above 1to below 1with increasing w(SiO2)/w(V2O3), and the melting temperature of vanadium slag decreased first and then increased when BI′ was below 1. With the increase of FeO mass fraction, the w(SiO2)/w(V2O3) to achieve the lowest melting temperature increased. With the increase of w(SiO2)/w(V2O3), the variation of viscosity with temperature became more gentle, and the viscosity of molten vanadium slag increased at high temperature, while the viscosity decreased at low temperature. Considering the influence of viscosity on metal-slag interface reaction and slag loss, w(SiO2)/w(V2O3) of vanadium slag with 44wt.% FeO should be controlled as 0.7.