基于IMCT理论的CaO-SiO_2-MgO-Al_2O_3-Na_2O渣系的脱硫热力学模型

A thermodynamic model of desulfurization for CaO-SiO_2-MgO-Al_2O_3-Na_2O slag based on IMCT theory

为了精确表征含Na_2O渣系的脱硫能力,改善脱硫效果,基于熔渣离子与分子共存理论(IMCT)建立了CaO-SiO_2-MgO-Al_2O_3-Na_2O渣系结构单元的作用浓度计算模型和1 753 K时该渣系的脱硫热力学模型。并对渣系的总硫分配比及各自硫分配比的影响因素进行了讨论分析。理论结果表明,除LS,MgS外,随着Al_2O_3质量分数的增加,该渣系的脱硫能力明显下降,而MgO和Na_2O质量分数的增加,对提高渣系的脱硫能力具有明显的促进作用。此外,少量的Na_2O即可表现出很强的脱硫效果,这为含有Na_2O的冶金二次资源在铁水脱硫过程中的应用以及铁水脱硫渣系的优化提供了必要的理论依据。

In order to accurately characterize the desulfurization capacity of the Na2O-containing slag system and improve the desulfurization effect,the thermodynamic model for the mass action concentrations calculation for the CaOSiO2-MgO-Al2O3-Na2O slag system and the thermodynamic model of the desulfurization for the slag at 1 753 K were established,based on the ion and molecule coexistence theory(IMCT). Then the influence factors of total sulfur distribution ratio and the respective sulfur distribution ratio of the slag were discussed and analyzed. The theoretical results showed that,aparting from the LS,Mg S,with the increasing of the mass percent of Al2O3,the desulfurization capacity of the slag significantly decreased. While the increasing of the mass percent of Mg O and Na2O can significantly promote the desulfurization capability of the slag. In addition,a small amount of the mass percent of Na2O showed a strong effect on the desulphurization capability,which provided a theoretical basis for the application of the Na2O-containing secondary metallurgical resources and the optimization of the desulfurization slag system in the desulphurization process for the hot metal.