Fe2O3-FeO-MgO-O2体系中二价金属氧化物形成的热力学分析

Thermodynamic Simulation on Formation of Divalent Metal Oxide in Fe2O3-FeO-MgO-O2 System

采用Factsage热力学软件模拟了Fe2O3-FeO-MgO-O2体系中二价金属氧化物(RO相)的形成过程,包括不同成分、不同温度和不同氧分压对RO相形成过程的影响,并对RO相中各组元的活度进行了模拟计算。结果表明,随原料中Fe2O3含量的增加,RO相的开始熔化温度逐渐降低。模拟形成的RO相由MgO、Fe2O3和FeO组成,并且随温度升高,体系中Fe2O3逐渐失去O转变成FeO。在1650℃条件下,原料中Fe2O3含量的增加能够提高RO相中Fe2O3和FeO的活度,降低MgO的活度。降低氧分压能够加速Fe2O3向FeO转变,当氧分压从21.278 kPa降到1.013×10^-6kPa,RO相中的Fe2O3能够降到1.96 g以下,Fe元素主要以FeO的形式存在,模拟计算得到的RO相的成分更接近实际转炉渣中RO相的成分。

The formation of divalent metal oxide(RO phase)in Fe2O3-FeO-MgO-O2 system is Simulated by Factage.Specifically,the effect of component,sintering temperature and oxygen partial pressure on its formation is investigated.Besides,the activity of each composition in RO phase is calculated.The results show that RO phase consists of MgO,Fe2O3 and FeO;with the increase in the content of Fe2O3,the initial melting temperature of RO phase gradually decreases;the rise in the temperature could result in the transformation from Fe2O3 to FeO with losing O;particularly,the activity of Fe2O3 and FeO increases while that of MgO decreases at 1650℃with a rising content of Fe2O3 in raw material;the reaction rate of Fe2O3 transforming into FeO could be accelerated by reducing oxygen partial pressure;when the pressure drops from 21.278 kPa to 1.013×10^-6 kPa,the mass of Fe2O3 could be less than 1.96 g in RO phase,and Fe element mainly exists in the form of FeO.Therefore,the composition of RO phase simulated by Factage is similar to that in BOF slag.