Underground water reservoirs (UWR) of coal mine plays a significant role in enhancing the ecological environment and safeguarding water resources. The water stored in UWR, known as brine solution, seriously damages the mechanical properties of the coal pillar. However, the mechanical degradation characteristics of coal under the action of different concentration solutions are still unclear. In this paper, we propose a novel coal corrosion device to simulate the real environment, designed to ensure the effective dissolution of the solution to the samples. Here we show the results of brine solution corrosion tests, considering ion composition changes, microscopic CT imaging, and mechanical properties. The solution ion composition experiences significant changes after the corrosion test. The variation in ion content can reflect the reaction degree and trend of water–rock interaction; CT test visually demonstrates the microstructural changes, allowing for direct observation of dissolution, generation, and attachment phenomena. The specimen’s overall porosity increases after corrosion; Triaxial compression tests were conducted, and both solution concentration and corrosion time can cause varying degrees of mechanical parameters degradation. Our results demonstrate how solution concentration affects coal and the extent of its impact. We anticipate our research will contribute to the construction and long-term safety of UWR.

中文翻译：

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深入了解浓盐水溶液腐蚀煤的机械降解

煤矿地下水库对于改善生态环境、保护水资源具有重要作用。UWR 中储存的水（称为盐水溶液）会严重损害煤柱的力学性能。然而，不同浓度溶液作用下煤的机械降解特性尚不清楚。在本文中，我们提出了一种模拟真实环境的新型煤腐蚀装置，旨在确保溶液对样品的有效溶解。在这里，我们展示了考虑离子成分变化、显微 CT 成像和机械性能的盐水溶液腐蚀测试结果。腐蚀试验后溶液离子组成发生显着变化。离子含量的变化可以反映水岩相互作用的反应程度和趋势；CT测试直观地显示微观结构的变化，可以直接观察溶解、生成和附着现象。腐蚀后试件整体孔隙率增加；进行三轴压缩试验，溶液浓度和腐蚀时间都会引起不同程度的力学参数退化。我们的结果证明了溶液浓度如何影响煤炭及其影响程度。我们预计我们的研究将为 UWR 的建设和长期安全做出贡献。