To better understand the permeability of uranium sandstone, improve the leaching rate of uranium, and explore the change law of pore structure characteristics and blocking mechanism during leaching, we systematically analyzed the microstructure of acid-leaching uranium sandstone. We investigated the variable rules of pore structure characteristics based on nuclear magnetic resonance (NMR). The results showed the following: (1) The uranium concentration change followed the exponential law during uranium deposits acid leaching. After 24 h, the uranium leaching rate reached 50%. The uranium leaching slowed gradually over the next 4 days. (2) Combined with the regularity of porosity variation, Stages I and II included chemical plugging controlled by surface reaction. Stage I was the major completion phase of uranium displacement with saturation precipitation of calcium sulfate. Stage II mainly precipitated iron (III) oxide-hydroxide and aluminum hydroxide. Stage III involved physical clogging controlled by diffusion. (3) In the three stages of leaching, the permeability of the leaching solution changed with the pore structure, which first decreased, then increased, and then decreased.

为更好地了解铀砂岩的渗透率，提高铀的浸出率，探索浸出过程中孔隙结构特征和堵塞机理的变化规律，系统分析了酸浸铀砂岩的微观结构。我们研究了基于核磁共振 (NMR) 的孔隙结构特征的变化规律。结果表明：(1)铀矿酸浸过程中铀浓度的变化遵循指数规律。24小时后，铀浸出率达到50%。在接下来的 4 天里，铀的浸出逐渐减慢。(2)结合孔隙度变化规律，Ⅰ、Ⅱ期为地表反应控制的化学封堵。第一阶段是铀置换的主要完成阶段，硫酸钙饱和沉淀。阶段 II 主要沉淀铁 (III) 氧化氢氧化物和氢氧化铝。第三阶段涉及由扩散控制的物理堵塞。(3)在浸出的三个阶段中，浸出液的渗透率随孔隙结构的变化而变化，先减小后增大再减小。