钒钛磁铁矿碳热合成铁基复合材料的热力学分析

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

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。

Based on HSC, a computational chemistry software, the thermodynamic analysis and equilibrium composition calculation were carried out for vacuum carbethermal reduction of a muh-component and muhi-phase complex system composed of vanadium-titanium mag- netite and reductant. The result of thermodynamic analysis showed that Fe is the ultimate stable phase for carbothermal reduction of ferrif- erous oxides, the reaction Gibbs energy of producing TiC is the lowest among all possible earbothermal redu,3tion of titanium oxides above 1 600 K, whereas the reaction Gibbs energy of producing VO2 is the lowest among the carbothermal reduction of V205 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 l 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 ℃.