This work aimed to obtain the kinetic parameters of the hydrothermal dissolution of a Brazilian glauconitic siltstone (known as Verdete) with calcium hydroxide. Heat treatments were carried out in stainless steel autoclaves internally coated with Teflon in conventional and rotary (84 rpm) furnaces. The aqueous fraction of hydrothermal products was analyzed by flame photometry and pH-metry. The product was also characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). After an initial inertia of 30–45 min, the concentration of OH⁻ ions decreased as K⁺ ions were extracted from the K-feldspar structure. K recovery was proportional to the Ca(OH)₂/Verdete ratio and gradually increased over time, reaching 65% after 24 h. Ca(OH)₂ and Verdete agglomerated when high temperatures (453 K) and Ca(OH)₂/Verdete ratios were employed simultaneously, causing loss of reaction surface area and interruption of the dissolution process. Agglomerations were avoided when rotating the furnace. However, rotation did not seem to increase the K⁺ extraction rate, which demonstrated to be proportional to OH⁻ concentration. The dissolution reaction was half-order in respect to OH⁻ concentration, and presented a 26.9 kJ mol⁻¹ activation energy.

这项工作的目的是获得用氢氧化钙水溶溶解巴西古洛冈质粉砂岩（称为Verdete）的动力学参数。在传统和旋转（84 rpm）炉中，在内部涂有特氟隆的不锈钢高压釜中进行热处理。通过火焰光度法和pH值测定法分析水热产物的水部分。该产物还通过X射线衍射（XRD）和扫描电子显微镜（SEM）表征。的30-45分钟的初始惯性后，OH的浓度^-如K离子降低⁺离子从钾长石结构萃取。钾的恢复与Ca（OH）₂ / Verdete的比例成正比，并随时间逐渐增加，在24小时后达到65％。钙（OH）₂当同时使用高温（453 K）和Ca（OH）₂ / Verdete比时，Verdete会聚结，从而导致反应表面积的损失和溶解过程的中断。旋转炉子时避免结块。然而，旋转似乎没有增加ķ ⁺萃取率，这证明是成比例的OH ^-浓度。溶解反应是半阶在相对于OH ^-浓度，并且提出了一个26.9千焦摩尔^-1活化能。