Thermodynamic modeling of motlen salt solutions with multivalent cations having multiple coordination numbers

具有多个配位数的多价阳离子的熔融盐溶液的热力学建模

• 批准号: 283306-2008
• 负责人: Chartrand, Patrice
• 金额: $ 1.68万
• 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: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=480351
• 关键词: Thermodynamic; modeling; motlen; salt; solutions

Thermodynamic and phase equilibrium modeling of multicomponent systems is of great industrial importance nowadays. The metallurgical and chemical industries commonly use thermochemical packages to simulate chemical reactions and phase equilibria for process development. Multicomponent multivalent salts systems are widely used for the production and processing of metals. Al electrolysis, coating of refractory metals, the next generation of nuclear reactors, promising electrolytes for Ti production all depend on molten salt chemistry. The thermodynamic and phase equilibrium modeling of multicomponent salt systems consists in expanding the Gibbs energy of a phase as a function of T, P and composition and finding a global energy minimum. Model parameters of the Gibbs energy functions are obtained by optimizing their values to best reproduce simultaneously the experimental data found in the literature (enthalpy, liquidus, etc.). Parameters form a database and the models are used to predict phase equilibria and thermodynamic properties in the multicomponent system. The Gibbs energy models must agree with the ionic structure of the multicomponent melt (oxidation states and coordination of ions), especially for complex chloro-fluoride melts dissolving some oxide components with cations of variables valency as the NaF-KF-NaCl-KCl-TiFx-TiClx (x=2, 3, 4) system. The proposed project consists in developing models and databases of parameters for the prediction of phase equilibria (liquidus and eutectic temperatures, stable products, vapor pressures) and thermodynamic properties (activities, enthalpy, Cp) of multicomponent reciprocal salts systems of industrial importance, with the novelty of taking into account the coordination numbers and oxidation states of the ions as they changes with composition. Models will be developed for the NaF-KF-NaCl-KCl-TiF2-TiCl2-TiF3 -TiCl3-TiF4-TiCl4 and the AF-BeF2-ThF4-UF3-UF4-UF6 (where A is an alkali) systems. Solid solutions and pure compounds will also be integrated in the model. For the liquid solution, Ti and U will have several coordination numbers (4-8) and their relative stabilities with composition will be calibrated on measurements.

如今，多组分系统的热力学和相平衡建模变得非常重要。冶金和化学工业通常使用热化学包来模拟化学反应和相位平衡以进行过程发展。 多组分多价盐系统被广泛用于金属的生产和加工。 Al Electroslesy，耐火金属的涂层，下一代的核反应堆，有望产生的电解质都取决于熔融盐化学。多组分盐系统的热力学和相平衡模型包括扩展相位的吉布斯能量作为T，P和组成的函数，并找到全球能量的最小值。 Gibbs能量函数的模型参数是通过优化其值以最能同时再现文献中发现的实验数据（焓，Liquidus等）来获得的。参数形成数据库，模型用于预测多组分系统中的相位平衡和热力学特性。 Gibbs能量模型必须与多组分熔体的离子结构（氧化态和离子配位）的离子结构一致，尤其是对于复杂的氯氟化物融化，将某些氧化物溶解的氧化物溶解了一些变量价值作为NAF-KF-NAF-KF-NAF-NAF-KCL-KCL-KCL-kcl-kcl-tifx-tifx-ticlx（x = 2，3，4）系统。所提出的项目包括开发参数的模型和数据库，以预测相位平衡（液体和共晶温度，稳定的产品，蒸气压力）和热力学特性（活动，焓，CP）的工业重要性系统的多层相互盐系统，并随着组成的组成和氧化而变化。 将为NAF-KF-NACL-KCL-TIF2-TIF2-TIF3-TIF3-TIF4-TIF4-TIF4和AF-BEF2-THF4-THF4-UF3-UF4-UF6（其中A是碱系统）开发模型。固体溶液和纯化合物也将集成在模型中。对于液体溶液，Ti和U将具有几个配位数（4-8），其组合物的相对稳定性将在测量上进行校准。