Thermodynamic models for metal-salt-oxide liquid solutions

金属盐氧化物液体溶液的热力学模型

• 批准号: RGPIN-2018-06655
• 负责人: Chartrand, Patrice
• 金额: $ 3.35万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=647249
• 关键词: Thermodynamic; models; metal; salt; oxide

The objective of the proposed research program is to develop a strong and systematic approach for the modeling of mixed metallic and ionic molten phases in order to obtain reliable predictions of the liquid phase thermodynamic properties and its equilibria with solid and gas phases in multicomponent systems of industrial and scientific interests. Primary metals production & recycling are typically performed in the molten state at high temperature, usually in the presence of ionic liquid fluxes (molten salts, slags, mattes). Science & Engineering are today heavily dependent on models and simulation tools to provide reliable predictions of the behavior of matter in different processes and materials. When chemical aspects are involved, thermodynamic models are at the core of these simulation tools, and are essential to provide the driving forces for reactions, transformations, diffusion of species under different conditions. The CALPHAD Method has very strongly established itself as a mandatory tool in the calculation of phase equilibria and thermodynamic properties of metallurgical and chemical inorganic systems. It consists in developing Gibbs energy functions, calibrated on experimental data and First-Principles calculations, for every given phase in a chemical system. Chemical and phase equilibria can be computed by the use of minimization techniques applied to find the combination and composition of phases that give a minimum in the energy. This approach is now applied worldwide for multicomponent chemical systems. ***Unfortunately, the proper modeling of the miscibility and immiscibility between liquid metals and molten oxides/salts is not well established, especially relative to the known chemical species that are affecting their electrical conductivity. Molten metal-salt equilibria show cases of full liquid miscibility (Fe-FeS, Cs-CsCl), partial miscibility (Cu-Cu2O), strong immiscibility (Cu-Cu2S, Li-LiF), or virtually complete immiscibility (Mg-MgCl2).***The scientific approach in this project consist in systematic tests and implementation of a liquid thermodynamic model which will use ion species derived from the electrical conductivity measurements to cover, with a single Gibbs energy function, the complete composition range between the liquid metal and the ionic composition range. This model will be tested for alkali metal-alkali halide salts, for Mg-Cd-Bi-chlorides and for metal alloys that exhibits a partial ionic character, such as the alkali-heavy metals, and finally for the Cu-Fe-S-O-Si system used for Cu-smelting and converting. For the first time, the proposed research permit to evaluate correctly both the metal dissolution in ionic melts and non-metal dissolution in alloys. Benefits for Canada will be in the field of metal production (Cu smelting, specialty metals and alloys) and in the energy efficiency by increasing current efficiency in electrolysis.

拟议的研究计划的目的是为混合金属和离子熔融阶段建模一种强大而系统的方法，以便获得对液相热力学特性的可靠预测以及其在工业型多组分系统中具有固体和气相的平衡和科学利益。通常在高温下，通常在熔融状态下，通常在存在离子液体通量（熔融盐，矿渣，哑光）下进行原代金属的生产和回收。如今，科学与工程在很大程度上取决于模型和仿真工具，以提供对不同过程和材料中物质行为的可靠预测。当涉及化学方面时，热力学模型是这些仿真工具的核心，对于在不同条件下的反应，转化，物种扩散的驱动力至关重要。 Calphad方法非常强烈地确立了自己的强制性工具，用于计算冶金和化学无机系统的相位平衡和热力学特性。它包括开发Gibbs能量功能，在化学系统中的每个给定阶段对实验数据和第一原理计算进行校准。可以通过使用最小化技术来计算化学和相位平衡，以找到最少能量的相结合和组成。现在，全世界将这种方法用于多组分化学系统。 ***不幸的是，液体金属和熔融氧化物/盐之间的混溶性和不混溶性的正确建模尚未得到很好的确定，尤其是相对于影响其电导率的已知化学物种。熔融金属盐平衡显示了全液体混溶的病例（Fe-Fes，CS-CSCL），部分混溶性（CU-CU2O），强烈的不混可能性（CU-CU2S，LI-LIF）或几乎完全不认真（MG-MGCL2） 。和离子成分范围。该模型将测试用于碱金属盐盐盐，MG-CD-BI-氯化物和具有部分离子特性的金属合金，例如碱性重的金属，最后用于Cu-fe-S-O-- SI系统用于熔化和转换。拟议的研究许可证首次可以正确评估离子熔体中的金属溶解和合金中非金属溶解。 加拿大的好处将在金属生产（Cu冶炼，特种金属和合金）中，以及通过提高电解的当前效率来获得能源效率。