Kinetics of Dissolution and Crystal Growth of Silicates and Aluminosilicates in Aqueous Solutions at Low Temperatures

我们将继续研究实验性的 溶解和沉淀动力学的测定 硅酸盐和铝硅酸盐作为pH值的函数， 温度，离子强度，和吉布斯自由能 反应（Δ G）;检查反应的表面 矿物表面分析技术（XPS，AES，SEM， 特别是AFM），当与利率相结合时， 通过溶液化学测定，使用流通 反应堆将提供有关表面反应的信息 机制;并将获得的速率数据应用于模型低 温场情况特别是皮吉格斯、铝土矿 存款我们的实验工作继续领先 描述溶解和沉淀的方法 主要造岩硅酸盐和铝硅酸盐的比率 也是第一个测量 比石英更复杂的相的沉淀速率。 的 非平凡的全速率法律，已在我们的 以前的工作现在可以纳入一个准确的两个- 多孔介质三维流体力学模型 媒体 随着这里提出的持续工作， 实验、理论和模型的综合结果应该是第一个 完全定量的物理化学模型 动态沉积盆地中的成岩作用和化学 主要铝土矿存款的演变。

We will continue studies of the experimental determination of the dissolution and precipitation kinetics of silicates and aluminosilicates as functions of pH, temperature, ionic strength, and the Gibbs Free energy of reaction (delta G); to examine the surfaces of the reacted minerals using surface analytical techniques (XPS, AES, SEM, AFM in particular), which when combined with rates determined from solution chemistry using flow-through reactors will provide information on surface reaction mechanisms; and to apply the rate data obtained to model low temperature field cases in particular the Pijiguaos, bauxite deposit Venezuela Our experimental work continues to lead the way in describing both dissolution and precipitation rates of major rock-forming silicates and aluminosilicates as a function delta G, as well as being the first to measure precipitation rates in phases more complex than quartz. The non-trivial full rate laws that have been developed in our prior work can now be incorporated into an accurate two- dimensional hydrodynamic model of fluid flow in porous media. With the continuing work proposed here, the coupling of experiment, theory and models should result in the first completely quantitative physical and chemical model of diagenesis in a dynamic sedimentary basin and to chemical evolution in a major bauxite deposit.