Thermodynamics of the natural assemblages of Ni-Co-Mn-Cu-Fe-Zn arsenates

Ni-Co-Mn-Cu-Fe-Zn砷酸盐自然组合的热力学

• 批准号: 511078261
• 负责人: Professor Dr. Juraj Majzlan, Ph.D.
• 金额: --
• 依托单位: Lehrstuhl Allgemeine und Angewandte Mineralogie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/511078261?language=en
• 关键词: Thermodynamics; natural; assemblages; Ni; Co

The first goal of the proposed work is the determination of thermodynamic properties of synthetic analogs of selected secondary minerals from Jáchymov. These are i) minerals of the krautite group [M(AsO3OH)·H2O minerals with M = Mn, Zn, Co, Mg, Ca, or Ca/Mn], ii) arsenates of the vivianite group [M3(AsO4)2·8H2O, where M = Ni, Co, Zn, Mg, Mn, Fe, and Cu], and iii) acidic ferric arsenate-sulfates kaatialaite [Fe(AsO2(OH)2)·5H2O] and sarmientite [Fe2(AsO4)(SO4)(OH)·5H2O]. Selected minerals from these groups will be synthesized and their thermodynamic properties determined by a combination of calorimetric techniques. The selection is based on the field work in the underground spaces in a historical Ag-Ni-Co-U(-As-Bi) ore deposit Jáchymov (Joachimsthal). The underground spaces of the historical Ag-Ni-Co-U(-As-Bi) deposit Jáchymov offer a natural laboratory with many local environments which we investigated in our previous work. The data obtained within the proposed work will be used to understand and numerically model the formation of the secondary minerals.The second goal of the project is the extension of applicability of a large thermodynamic data set for secondary minerals for temperatures between 0-200 oC. This work will be achieved by fitting the already existing data sets by a combination of Debye-Einstein functions, calculating the solubility constants at various temperatures using the appropriate software (SUPCRT) and tabulating the results. This work will allow the entire geochemical community to use the data to model any process involving many secondary arsenates, sulfates, or oxides.

拟议工作的第一个目标是确定从Jáchymov选定的次生矿物的合成类似物的热力学性质。它们是：i）黄绿铁矿族矿物[M（AsO_3 OH）·H_2O矿物，其中M = Mn、Zn、Co、Mg、Ca或Ca/Mn]，ii）蓝铁矿族砷酸盐[M_3（AsO_4）_2·8H_2O，其中M = Ni、Co、Zn、Mg、Mn、Fe和Cu]，（3）酸性砷酸硫酸铁钾铁矾[Fe（AsO 2（OH）2）·5 H2O]和硫砷铁矾[Fe 2（AsO 4）（SO 4）（OH）·5 H2O]。将合成这些组中的选定矿物，并通过量热技术的组合确定其热力学性质。该选择是基于在历史悠久的Ag-Ni-Co-U（-As-Bi）矿石存款Jáchymov（约阿希姆斯塔尔）地下空间的野外工作。历史悠久的Ag-Ni-Co-U（-As-Bi）存款Jáchymov的地下空间提供了一个天然的实验室，我们在以前的工作中调查了许多当地环境。在拟议的工作中获得的数据将用于理解和数值模拟次生矿物的形成。该项目的第二个目标是扩展适用于0-200 oC温度之间的次生矿物的大型热力学数据集。这项工作将通过结合Debye-Einstein函数拟合现有数据集，使用适当的软件（SUPCRT）计算不同温度下的溶解度常数并将结果制成表格来实现。这项工作将允许整个地球化学界使用这些数据来模拟任何涉及许多次生砷酸盐、硫酸盐或氧化物的过程。