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标是开发一个强大的和系统的方法，用于混合金属和离子熔融相的建模，以获得可靠的预测液相热力学性质及其与工业和科学利益的多组分系统中的固相和气相的平衡。原生金属的生产和回收通常在高温下以熔融状态进行，通常在离子液体助熔剂（熔融盐，炉渣，冰铜）的存在下进行。科学与工程今天严重依赖模型和仿真工具，以提供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，热力学模型是这些模拟工具的核心，并且对于提供不同条件下的反应，转化，物种扩散的驱动力至关重要。CALPHAD方法已经成为冶金和化学无机体系相平衡和热力学性质计算的强制性工具。它包括开发吉布斯能函数，校准实验数据和第一性原理计算，为每一个给定的阶段在化学系统。化学平衡和相平衡可以通过使用最小化技术来计算，该最小化技术用于找到给出能量最小值的相的组合和组成。这种方法现在在全世界范围内应用于多组分化学体系。* 不幸的是，液态金属和熔融氧化物/盐之间的可熔性和不可熔性的适当建模尚未建立，特别是相对于影响其电导率的已知化学物质。熔融金属-盐平衡显示完全液体可溶解性（Fe-FeS、Cs-CsCl）、部分可溶解性（Cu-Cu 2 O）、强不可溶解性（Cu-Cu 2S、Li-LiF）或几乎完全不可溶解性（Mg-MgCl 2）的情况。该项目的科学方法包括系统测试和实施液体热力学模型，该模型将使用来自电导率测量的离子种类，以单个吉布斯能量函数覆盖液体金属和离子组成范围之间的完整组成范围。该模型将用于碱金属-碱金属卤化物盐、Mg-Cd-Bi-氯化物和表现出部分离子特征的金属合金（例如碱金属-重金属），以及最后用于铜熔炼和转化的Cu-Fe-S-O-Si系统。第一次，拟议的研究许可证，以正确地评估在离子熔体中的金属溶解和合金中的非金属溶解。 加拿大将受益于金属生产领域（铜冶炼、特种金属和合金）以及通过提高电解电流效率提高能源效率。