Leaching zones within potash seams generally represent a significant risk to subsurface mining operations and the construction of technical caverns in salt rocks, but their temporal and spatial formation has been investigated only rudimentarily to date. To the knowledge of the authors, current reactive transport simulation implementations are not capable to address hydraulic-chemical interactions within potash salt. For this reason, a reactive transport model has been developed and complemented by an innovative approach to calculate the interchange of minerals and solution at the water-rock interface. Using this model, a scenario analysis was carried out based on a carnallite-bearing potash seam. The results show that the evolution of leaching zones depends on the mineral composition and dissolution rate of the original salt rock, and that the formation can be classified by the dimensionless parameters of Péclet (Pe) and Damköhler (Da). For Pe > 2 and Da > 1, a funnel-shaped leaching zone is formed, otherwise the dissolution front is planar. Additionally, Da > 1 results in the formation of a sylvinitic zone and a flow barrier. Most scenarios represent hybrid forms of these cases. The simulated shapes and mineralogies are confirmed by literature data and can be used to assess the hazard potential.

中文翻译：

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钾盐煤层中浸润区的时空演变

钾盐煤层中的浸出区通常对地下采矿作业和盐岩中的技术洞穴的建设构成重大风险，但迄今为止，对它们的时间和空间形成仅作了初步的研究。据作者所知，当前的反应性运输模拟实施方案无法解决钾盐内的水化学相互作用。因此，已经开发了反应性输运模型，并通过一种创新的方法对其进行了补充，以计算水-岩界面处矿物和溶液的交换率。使用该模型，基于含角砾岩的钾盐煤层进行了情景分析。结果表明，浸出区的演化取决于原始盐岩的矿物成分和溶解速率，并且可以通过佩克利特（Pe）和达姆科勒（Da）的无量纲参数对地层进行分类。当Pe> 2且Da> 1时，会形成一个漏斗形的浸出区，否则溶解前沿是平面的。此外，Da> 1会导致形成一个乙烯基区和一个阻流层。大多数情况代表这些情况的混合形式。文献数据证实了模拟的形状和矿物学，可用于评估潜在危险。