Nonmagmatic, carbonate-hosted epigenetic hydrothermal Pb–Zn deposits similar to those at the Huize Pb–Zn Mine are widespread across the Sichuan–Yunnan–Guizhou (SYG) polymetallic province. The precipitation mechanisms of these geologically intriguing deposits are an area of interest for many researchers. To simulate the underlying precipitation reaction mechanisms and dynamics of each aspect, a fluid mixing model for metal sulfide precipitation was used in a series of experiments, where solutions that contain Pb/Zn chloride complexes and sulfide were subjected to pH changes, water-rock reactions, and dilutions. Based on the results of these experiments, thermodynamic phase diagrams, and other experimental findings, a fluid mixing genetic model was developed for SYG Pb–Zn deposits, and this model was used to analyze the mechanisms of metal sulfide precipitation. The results indicate that acidic fluids in the form of chloride complexes transported Pb and Zn, whereas sulfide exists in the form of H₂S within these fluids. The precipitation of metal sulfides occurs when these fluids undergo changes in pH, water-rock reactions, or isothermal dilution. The pH changes were found to be the most effective method for the induction of sulfide precipitation, followed by dilution and then water-rock reactions. The formation of sulfide precipitates due to pH changes, water-rock reactions, and dilution can be attributed to a single mechanism, i.e., changes in the pH of the fluid. Therefore, changes in pH are the primary mechanism of sulfide precipitation.

中文翻译：

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流体混合模型模拟矿床的沉淀反应机理

与会泽铅锌矿相似的非岩浆碳酸盐岩表生热液铅锌矿床遍布四川-云南-贵州（SYG）多金属省。这些有趣的地质沉积物的沉淀机制是许多研究人员关注的领域。为了模拟各方面的基本沉淀反应机理和动力学，在一系列实验中使用了金属硫化物沉淀的流体混合模型，对含Pb / Zn氯化物配合物和硫化物的溶液进行pH值变化，水-岩反应。以及稀释液。根据这些实验的结果，热力学相图和其他实验结果，开发了SYG Pb-Zn矿床的流体混合遗传模型，用该模型分析了金属硫化物沉淀的机理。结果表明，氯化物络合物形式的酸性流体以铅和锌的形式传输，而硫化物以氢的形式存在。_2个这些流体中S上。当这些流体的pH值发生变化，发生水岩石反应或等温稀释时，就会发生金属硫化物的沉淀。人们发现，pH改变是诱导硫化物沉淀，稀释，然后进行水-岩石反应的最有效方法。由于pH值变化，水岩石反应和稀释而导致的硫化物沉淀物的形成可以归因于单一机理，即流体pH值的变化。因此，pH的变化是硫化物沉淀的主要机理。