含钛高炉渣活度模型的建立及热力学分析

根据分子离子共存理论,建立了CaO-SiO2-MgO-Al2O3-TiO2含钛高炉渣活度模型,模型计算结果与实验测定结果吻合较好.利用该模型并结合相图计算分析了碱度和w(TiO2)对含钛高炉渣主要组元活度的影响.结果表明,含钛高炉渣中钛的主要赋存相是CaO·TiO2,1500℃时典型含钛高炉渣中CaO·TiO2的活度为0.18.随着碱度和w(TiO2)增加,CaO·TiO2活度先增后减.当碱度区间在1.08~3.08,w(TiO2)在26%~43%的条件下,有利于CaO·TiO2活度的增加,促进钛组分在钙钛矿中富集.CaO·TiO2活度最大值所需碱度随TiO2含量的增加而增加,当含钛高炉渣中w(TiO2)为20%~28%时碱度为1.34~1.63,对促进钛在钙钛矿中的富集是有利的.

The Activity Model and Thermodynamic Analysis for Ti-Bearing Blast Furnace Slag

Based on the coexistence theory of molecules and ions in slags， an activity model of CaO-SiO₂-MgO-Al₂O₃-TiO₂ was constructed， and the calculated result was in good agreement with experimental data. Combined with the phase diagram， the activity model was used to calculate the influences of slag basicity and w(TiO₂) on the activities of the main components in slag. The calculated result indicates that the component containing TiO₂ is mainly CaO·TiO₂， and the activity of CaO·TiO₂ is 0.18 at 1500°C. The activity of CaO·TiO₂ increases first and then decreases with the increase of w(TiO₂) and basicity. It is better for the increase of activity of CaO·TiO₂ when the basicity is between 1.08 and 3.08 and w(TiO₂) is between 26% and 43%， which is benefit for the enrichment of titania as CaO·TiO₂.The corresponding basicity for maximum activity of CaO·TiO₂ increases with the increase of w(TiO₂)， and the basicity is between 1.34 and 1.63 when w(TiO₂) is between 20% and 28%， while the maximum enrichment of titania as CaO·TiO₂ can be obtained.