Abstract: Uranium is an important nuclear fuel，and supercritical CO2 fluid leaching is a new，efficient and environmentally safe uranium extraction method. The aim of this experiment was to investigate the impact of pressure and time on uranium leaching efficiency with FeCl3 as reactant. Leaching efficiency first increased and then decreased with the increase of pressure. Under a constant specific pressure leaching efficiency first increased with increasiing time and then stabilized at a fixed value. The optimum leaching pressure was 10MPa，and leaching efficiency could reach 90%. Compared with the traditional acid-alkali leaching of uranium，leaching effect was significantly higher. Supercritical CO2 fluid leaching could be used for in-situ uranium leaching of low grade sandstone-type uranium deposits.

Key words: supercritical CO2 fluid, leaching of uranium, sandstone-type uranium deposites, FeCl3, time, pressure

摘要： 铀是重要的核能燃料，而超临界CO2是一种新型高效且环境安全性的铀提取方法。在FeCl3作为反应剂的前提下，考察了主要因素压力和时间对浸取效果的影响。恒定时间下随着压力的增加浸出率是先增加后减少，恒定压力下随着时间的增加浸出率是先增加然后是到稳定状态。最佳浸出条件为压力10MPa，浸出率可达90%。与传统的酸碱浸取铀相比，浸取效果要明显高于常规采铀。所以超临界CO2流体浸取有望应用于低品位砂岩铀矿的地浸采铀中。

关键词: 超临界CO2流体, 浸取铀, 砂岩型铀矿, 三氯化铁, 时间, 压力