Abstract Rare earth (RE) with specific application value has become the relatively important strategic resource for all countries. Weathered crust elution-deposited rare earth ore (WCED-REO) are rich in middle-heavy RE, and its exploitation restrict the global supply of the middle-heavy RE. The leaching technology directly determines the leaching efficiency of RE in WCED-REO. The selection and use of the leaching agents are the most important parts of the leaching technology. The leaching mechanism is at the core of the leaching technology and also affects the effective utilization of the leaching agents. The research and development of leaching technologies, leaching agents, and leaching mechanisms of WCED-REO are discussed in this article. The development processes of exiting leaching technologies are introduced. The advantages and disadvantages of barrel leaching, pool leaching, heap leaching, in-situ leaching, and other leaching technologies are compared. And the new and practical leaching technologies are put forward. The research progresses of ammonium salt leaching agents, composite ammonium salt leaching agents, and novel non-ammonium leaching agents in recent years are reviewed. The leaching effects of different leaching agents are compared comprehensively to provide guidance for industrial application and research direction of the best leaching agent in the later period. The leaching basic theory, as well as the mass transfer process and leaching kinetics of rare earth are introduced. The mass transfer processes in leaching mechanism are explained from the macroscopic and microscopic perspectives. The further research directions of the leaching technologies, leaching agents, and leaching mechanism of WCED-REO are put forward, which provide the theoretical guidance and technical supports for the green and efficient exploitation of WCED-REO.

中文翻译：

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风化壳淋溶型稀土矿浸出技术与理论研究进展

摘要 具有特定应用价值的稀土已成为各国较为重要的战略资源。风化壳洗脱沉积型稀土矿（WCED-REO）富含中重稀土，其开采限制了全球中重稀土供应。浸出技术直接决定了WCED-REO中RE的浸出效率。浸出剂的选择和使用是浸出技术中最重要的部分。浸出机理是浸出技术的核心，也影响着浸出剂的有效利用。本文讨论了WCED-REO浸出技术、浸出剂和浸出机理的研究与发展。介绍了现有浸出技术的发展历程。比较了桶浸、池浸、堆浸、原位浸出等浸出工艺的优缺点。并提出了新型实用的浸出技术。综述了近年来铵盐浸出剂、复合铵盐浸出剂和新型非铵浸出剂的研究进展。综合比较不同浸出剂的浸出效果，为后期最佳浸出剂的工业应用和研究方向提供指导。介绍了稀土的浸出基本理论，以及稀土的传质过程和浸出动力学。从宏观和微观角度解释了浸出机理中的传质过程。