Kinetics of the Smectite-Illite Transformation: An Experimental Study

将在不同温度下对粘土进行一系列实验， 硅、铝和钾的浓度， 从25 oC到300 oC。 新的实验技术， 所提出的研究已经过全面测试。 它包括 通过两个进料弹双重泵送溶液， 石英或勃姆石，其通过它们的平衡溶解度提供 在受控的温度下，固定但可调节的二氧化硅， 输入溶液中的铝浓度。 拟议 实验中，小尺寸的粘土样品将被悬浮， 反应器内的流化床。 固体样品和 然后在每次运行期间提取溶液， 反应的进展，以及各种分析技术将是 用于评估流体和固体中的成分变化， 伊利石/蒙脱石样品的结构状态。 的结果 这些实验在几个方面都很重要。 第一、 它们将为流体流动建模提供动力学数据， 成岩作用 在这样的模型中，水的释放， 孔隙度降低，流体化学和压力变化 与伊利化相关的重要过程必须 日期被高度参数化。 其次，他们应该解决 蒙皂石向伊利石转化的机理。 积极 关于非法化是否通过 固态或溶解-再沉淀路径。在我们的 实验，控制流体成分和流量的能力 率（因此系统的“封闭性”）允许我们评估是否 这些因素影响反应的速率和能量学， 它们是否由表面动力学的质量传递控制 通过元素反应或通过多种途径。 在 除了对伊利石化动力学的重要性外， 这里提出的工作将扩大有价值的平衡溶解度 May等人（1986）和Aja等人（1991 a，B）关于 K_2 O-MgO-Al_2O_3-SiO_2-H_2O系统的相稳定性。 的 实验结果也应该解决是否基本 粒子解释是溶液或多相混合物 (e.g., Tardy和Fritz，1981年; Aagaard和Helgeson，1983年; Nadeau等 例如，1984; Garrels，1984;和Altaner，1988）。

A series of experiments will be undertaken on clays under differing silica, aluminum, and potassium concentrations, at temperatures from 25oC up to 300oC. The new experimental technique for the proposed research has been thoroughly tested. It incorporates the dual pumping of solutions through two feeder-bombs containing quartz or boehmite which provide, by their equilibrium solubilities at controlled temperatures, fixed but adjustable silica and aluminum concentrations in the input solutions. In the proposed experiments, the narrowly sized clay samples will be suspended as fluidized bed within the reactor. Samples of both the solid and the solutions will then be extracted during each run to track the reaction progress, and a variety of analytical techniques will be used to evaluate compositional changes in the fluids and solids and the structural state of the illite/smectite sample. The results of these experiments will be important in several respects. First, they will provide kinetic data for modeling fluid-flow and diagenesis on a basin scale. In such models the release of water, reduction in porosity, and change in fluid chemistry and pressure associated with illitization are important processes that have to date been highly parameterized. Secondly, they should resolve the mechanism of the smectite to illite transformation. An active controversy persists as to whether illitization proceeds via a solid-state or a dissolution-reprecipitation path. In our experiments, the ability to control the fluid composition and flow rate (hence "closedness" of the system) allows us to assess whether these factors affect the rates and energetics of the reaction and whether they are dominated by mass transport of surface kinetics through an elemental reaction or through multiple pathways. In addition to its significance to the kinetics of illitization, the work proposed here will extend the valuable equilibrium solubility results of May et al. (1986)and of Aja et al. (1991a, b) on the stabilities of phases in the K2O-MgO-Al2O3-SiO2-H2O system. The experimental results should also resolve whether the fundamental particle explanation is solution or a mixture of multiple phases (e.g., Tardy and Fritz, 1981; Aagaard and Helgeson, 1983; Nadeau et al., 1984; Garrels, 1984; and Altaner, 1988).