Vermiculite is a mineral with many potential uses in various industrial areas, such as in insulation, horticulture, and environmental applications. The regolith of the Sokli carbonatite intrusion in northern Finland consists of weathered micas which reportedly contain vermiculite. The aim of the present study was to characterize the weathered mica in order to determine if the weathered regolith contains vermiculite. If so, the value of the apatite-rich Sokli intrusion may increase, because the vermiculite could be classified as an ore in Sokli. For the characterization, mica fractions were investigated using electron probe microanalysis (EPMA), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The EPMA results show that the potassium (K2O) content of the mica investigated varies between 6.20 and 0.31 wt.%. The XRD results provided evidence that the interlayer distances in the mica vary between 10.1 and 14.7 Å. The TGA shows that the dehydration of the samples varies between 6 and 12 wt.% for temperatures up to 170°C. Dehydroxylation takes place in three steps, as is characteristic for vermiculite. The results from this study revealed that mica in the weathered parts of the Sokli carbonatite is mostly vermiculite, and that the vermiculite was formed by the weathering of phlogopite. These results can be used to determine whether vermiculite is a possible future commodity at the Sokli carbonatite complex.

中文翻译：

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来自芬兰北部 Sokli 的变种云母的表征

蛭石是一种在各种工业领域具有许多潜在用途的矿物，例如绝缘、园艺和环境应用。芬兰北部 Sokli 碳酸岩​​侵入体的风化层由风化云母组成，据报道含有蛭石。本研究的目的是表征风化云母，以确定风化风化层是否含有蛭石。如果是这样，富含磷灰石的 Sokli 侵入体的价值可能会增加，因为蛭石可以归类为 Sokli 的矿石。为了表征，使用电子探针微量分析 (EPMA)、X 射线衍射 (XRD) 和热重分析 (TGA) 研究了云母组分。EPMA 结果表明，所研究的云母的钾 (K2O) 含量在 6.20 至 0.31 重量％之间变化。XRD 结果证明云母中的层间距在 10.1 到 14.7 埃之间变化。TGA 显示，在高达 170°C 的温度下，样品的脱水率在 6 到 12 wt.% 之间变化。脱羟基分三个步骤进行，这是蛭石的特征。研究结果表明，Sokli碳酸岩风化部分的云母主要为蛭石，蛭石是金云母风化形成的。这些结果可用于确定蛭石是否是 Sokli 碳酸岩​​复合体未来可能的商品。这是蛭石的特征。研究结果表明，Sokli碳酸岩风化部分的云母主要为蛭石，蛭石是金云母风化形成的。这些结果可用于确定蛭石是否是 Sokli 碳酸岩​​复合体未来可能的商品。这是蛭石的特征。研究结果表明，Sokli碳酸岩风化部分的云母主要为蛭石，蛭石是金云母风化形成的。这些结果可用于确定蛭石是否是 Sokli 碳酸岩​​复合体未来可能的商品。