CaO-SiO2-MgO-Al2O3渣系渣铁间硫分配比热力学模型

 为了探明高炉渣系组成对高炉渣脱硫能力的影响,根据分子-离子共存理论,建立了CaO-SiO₂-MgO-Al₂O₃高炉渣系与铁液间硫分配比的热力学模型,利用试验测定值对其进行验证与修正,探究碱度R、w((MgO))/w((Al₂O₃))和w((Al₂O₃))对炉渣脱硫能力的影响。研究结果表明,修正后的CaO-SiO₂-MgO-Al₂O₃高炉渣系硫分配比(L_S)热力学模型能较好地预测熔渣的脱硫能力,修正后的相对误差为8%,较修正前的相对误差降低了11%;当w((MgO))/w((Al₂O₃))=0.25~0.45,w((Al₂O₃))=15%时,随着碱度R的增加,炉渣的脱硫能力(L_S)增大;当w((Al₂O₃))=15%,R=1.15~1.25时,随着w((MgO))/w((Al₂O₃))的增加,炉渣的脱硫能力(L_S)增大;当w((MgO))/w((Al₂O₃))=0.25~0.45,R=1.20时,随着w((Al₂O₃))的增加,炉渣的脱硫能力(L_S)减小,故高Al₂O₃条件下应适当增加炉渣中的w((MgO))/w((Al₂O₃))。

Thermodynamic model for calculating sulfur distribution ratio between CaO-SiO2-MgO-Al2O3 slag and hot metal

With a view to finding out the influence of slag compositions on desulfurization ability of blast furnace slag, a thermodynamic model for calculating the sulfur distribution ratio (L_S) between CaO-SiO₂-MgO-Al₂O₃ slag and hot metal has been developed based on the ion and molecule coexistence theory (IMCT) and modified with experimental values. The effects of basicity R, w((MgO))/w((Al₂O₃)), and w((Al₂O₃)) on the desulfurization ability (sulfur distribution ratio, L_S) of slag were also discussed. The results show that the modified thermodynamic model for calculating L_S between CaO-SiO₂-MgO-Al₂O₃ slag and hot metal can predict the desulfurization ability (L_S) of slag and the relative error of the modified model is 8%, which is 11% lower than that before modified. When w((Al₂O₃))=15% and w((MgO)/w((Al₂O₃))=0.25-0.45, L_S of slag increased with the increase of R. When w((Al₂O₃))=15% and R=1.15-1.25, L_S of slag increased with the increase of w((MgO))/w((Al₂O₃)). When R=1.20 and w((MgO))/w((Al₂O₃))=0.25-0.45, L_S of slag decreased with the increase of w((Al₂O₃)), which indicates that w((MgO))/w((Al₂O₃)) should be improved when w((Al₂O₃)) in the slag is high to keep enough desulfurization ability of the slag.