Mechanisms of Lithium Enrichment and Metallogenesis in a Simulated Montmorillonite-Fluid System.
Mechanisms of Lithium Enrichment and Metallogenesis in a Simulated Montmorillonite-Fluid System.
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DOI：
10.1021/acs.langmuir.3c01298
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发表时间：
2023-08
期刊：
影响因子：
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通讯作者：
Song Yan;Tao Sun;Yuanfeng Cai;Wei Li;Yuguan Pan;Jinhai Yu
中科院分区：
文献类型：
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作者：
Song Yan;Tao Sun;Yuanfeng Cai;Wei Li;Yuguan Pan;Jinhai Yu
由于工业对锂的强烈需求，含锂蒙脱石(Li-Mt)矿床是勘探的重点，但此类矿床中的锂富集机理尚不清楚。本研究通过吸附实验和矿物学分析，研究了不同Li浓度、不同温度、不同时间和不同pH条件下的水-岩反应，以揭示富F-和富Cl-体系中Li的富集机理。结果表明，两种卤素体系中的水-岩反应是不同的。在LiCl-Mt体系中发生的反应包括去质子化，而在LiF-Mt体系中发生脱羟基化。锂在山体中与层间阳离子吸附或交换。在LiCl体系中，吸附形成的单分子膜符合朗缪尔模型。锂在LiF体系中被多层吸附在Mt中。当Li浓度一定时，LiF-Mt体系的吸附容量是LiCl-Mt体系的2.8倍。在LiCl-Mt体系中，pH的影响弱于LiF-Mt体系。此外，在LiF体系中，过高或过低的pH都会阻碍Li的吸附。在核磁共振中，Li的化学位移为-0.2ppm(±0.1ppm)，表明Li以球内络合物的形式存在于Mt.根据CaCl2浸出实验，50%(高达97.94%)的李灿可以很容易地被交换出山体。内圈残余锂是锂-山矿床成矿的关键。因此，离子吸附型锂矿床的品位取决于可交换锂的含量。
Due to strong industrial demand for Li, Li-bearing montmorillonite (Li-Mt) deposits are a focus for exploration, but the Li enrichment mechanisms in such deposits are unclear. In this study, adsorption experiments and mineralogical analyses were used to investigate the water-rock reactions at different Li concentrations, temperatures, durations, and pH conditions, in order to reveal the Li enrichment mechanisms in F- and Cl-rich systems. Our results suggest that water-rock reactions are different in the two halogen systems. The reaction in the LiCl-Mt system involves deprotonation, whereas dehydroxylation occurs in a LiF-Mt system. Lithium is adsorbed or exchanges with interlayer cations in Mt. Adsorption forms a monolayer that is consistent with the Langmuir model in a LiCl system. Lithium is adsorbed in multi-layers in Mt in a LiF system. For a given Li concentration, the adsorption capacity of the LiF-Mt system is 2.8 times greater than that of the LiCl-Mt system. The pH has a weaker effect in the LiCl-Mt system than in the LiF-Mt system. Furthermore, Li adsorption is hindered at very high or low pH in a LiF system. The chemical shift of Li is -0.2 ppm (±0.1 ppm) in a nuclear magnetic resonance (NMR), which indicates that Li occurs as inner-sphere complexes in the pseudo-hexagonal cavity in Mt. Based on a CaCl2 leaching experiment, >50% (up to 97.94%) of the Li can be easily exchanged out of the Mt. The residual Li in the inner-sphere is the key to metallogenesis of Li-Mt deposits. Therefore, the grade of ion adsorption-type Li deposits is determined by the exchangeable Li.