钒钛磁铁矿碳热合成铁基复合材料的热力学分析

运用HSC软件对钒钛磁铁矿粉和还原剂构成的多元、多相复杂反应体系进行碳热还原反应的热力学计算及平衡相分析。热力学计算结果表明,铁氧化物碳热还原高温下的最终稳定相为Fe,在温度大于1 600 K下钛氧化物碳热还原生成TiC的反应吉布斯自由能最低,而在600～1 600 K,V2O5的碳热还原过程中生成VO2的反应吉布斯自由能最低,在高于1 348 K的温度下体系中才能得到VC,提高温度会促进VC的生成。平衡相组分计算结果表明,真空度为2 Pa时Fe、TiC、VC分别在400～1 300℃、900～1 300℃和800～1 300℃可以稳定存在。

Thermodynamic Analysis on Ferro-matrix Composites by In-situ Carbothermal Reduction from Vanadium-Titanium Magnetite

Based on HSC,a computational chemistry software,the thermodynamic analysis and equilibrium composition calculation were carried out for vacuum carbothermal reduction of a mult-component and multi-phase complex system composed of vanadium-titanium magnetite and reductant.The result of thermodynamic analysis showed that Fe is the ultimate stable phase for carbothermal reduction of ferriferous oxides,the reaction Gibbs energy of producing TiC is the lowest among all possible carbothermal reduction of titanium oxides above 1 600 K,whereas the reaction Gibbs energy of producing VO2 is the lowest among the carbothermal reduction of V2O5 between 600 K and 1 600 K,and VC can be obtained only above 1 348 K.High temperature can facilitate the production of VC.The equilibrium composition calculation showed that under the pressure of 2 Pa,the stable existing temperature of Fe is between 400 ℃ and 1 300 ℃,the stable existing temperature of TiC is between 900 ℃ and 1 300 ℃,and the stable existing temperature of VC is between 800 ℃ and 1 300 ℃.