稀散元素铟的地球化学行为及成矿作用研究进展

Research Progress on Geochemical Behavior and Mineralization of Scattered Element Indium

摘要: 铟(In)是战略性稀散元素，在半导体、光伏电池等高新技术领域有着不可替代的应用价值。受资源稀缺性与成矿复杂性影响，铟长期以来都是地球化学与矿产资源领域的研究热点。本文以“赋存机制–成矿过程–资源潜力”为核心，梳理了全球铟资源分布、地球化学特征、赋存状态、成矿规律及控制因素，分析了现有研究的局限与关键空白。研究显示，全球铟资源分布极不均衡，主要集中在中国、玻利维亚等国，中国2024年原生铟产量占全球71%，再生铟已成为重要供给来源。铟的主要赋存形式为闪锌矿中的类质同象，占全球铟产出的95%，但微纳米包裹体与吸附态赋存的贡献被长期低估。成矿温度、流体成分(Cl⁻浓度、pH值、氧逸度)及构造背景，共同影响铟的富集，贫锡矽卡岩型、锡石–硫化物型及铅锌多金属型矿床是主要富集载体，其成矿与岩浆–热液演化、流体–岩石相互作用密切相关。目前研究多依赖闪锌矿地球化学指标，对表生环境铟的迁移再富集、中小型矿床资源潜力评估存在不足。未来需重点攻克低品位铟精准识别、流体与铟富集耦合机制等问题，为铟矿高效勘探与综合利用提供理论支撑。

Abstract: Indium (In) is a strategic rare element, which has irreplaceable application value in high-tech fields such as semiconductors and photovoltaic cells. Affected by the scarcity of resources and the complexity of mineralization, indium has long been a research hotspot in the field of geochemistry and mineral resources. Based on the core of “occurrence mechanism - metallogenic process - resource potential”, this paper combs the distribution, geochemical characteristics, occurrence state, metallogenic regularity and control factors of global indium resources, and analyzes the limitations and key gaps of existing research. Studies have shown that the distribution of indium resources in the world is extremely uneven, mainly concentrated in China, Bolivia and other countries. In 2024, China’s primary indium production accounted for 71% of the world’s total, and recycled indium has become an important source of supply. The main occurrence form of indium is isomorphism in sphalerite, accounting for 95% of global indium output, but the contribution of micro-nano inclusions and adsorbed state occurrence has been underestimated for a long time. The ore-forming temperature, fluid composition (Cl O concentration, pH value, oxygen fugacity) and tectonic setting jointly affect the enrichment of indium. The tin-poor skarn type, cassiterite-sulfide type and lead-zinc polymetallic type deposits are the main enrichment carriers, and their mineralization is closely related to magmatic-hydrothermal evolution and fluid-rock interaction. At present, most studies rely on sphalerite geochemical indicators, and there are deficiencies in the migration and re-enrichment of indium in the supergene environment and the assessment of resource potential of small and medium-sized deposits. In the future, it is necessary to focus on the accurate identification of low-grade indium and the coupling mechanism of fluid and indium enrichment, so as to provide theoretical support for efficient exploration and comprehensive utilization of indium ore.