Thermodynamics of the minerals of the jarosite group

黄钾铁矾及相关矿物总是存在于酸雨或酸性矿井排水作用下酸化的自然环境中。尽管它们的重要性和普遍性，但描述黄钾铁矾和水溶液之间的溶解度、沉淀和元素分布的数据是破碎的或可疑的。在这里，我建议用量热法来确定黄钾铁矾类矿物的热力学性质（形成焓、熵和吉布斯自由能）。测量的热力学量将通过数学规划分析面对黄钾铁矾矿物的高P-T实验。结果将是一个内部一致的黄钾铁矾群矿物热力学数据集。所获得的系统分类学将为受酸性输入影响的环境中的溶解、降水、污染物运移和元素分馏模型提供良好的基础。

Jarosite and related minerals are invariably found in natural environments acidified either through the action of acid rain or by acidic mine drainage. In spite of their importance and common occurrence, the data which could describe the solubility, precipitation, and distribution of elements between jarosite and aqueous solutions are fragmented or questionable. Here I propose to determine the thermodynamic properties (formation enthalpy, entropy, and Gibbs free energy of formation) of the jarosite group of minerals by calorimetric techniques. The measured thermodynamic quantities will be then confronted with high P-T experiments on jarosite minerals via a mathematical programming analysis. The result will be an internally consistent thermodynamic data set for jarosite group minerals. The systematics obtained will provide an excellent basis for models of dissolution, precipitation, pollutant transport, and element fractionation in environments affected by acidic input.