Progress on enhancing seepage-leaching mass-transfer research for in-situ leaching mining of low-permeability uranium-bearing sandstone: a review

Sandstone-type deposits have emerged as the primary uranium deposits being mined in China, utilizing in-situ leaching technology. However, the leaching of uranium resources within sandstone formations faces significant constraints due to their extremely low permeability, accounting for approximately seventy percent of the total. This paper aims to present recent advancements in the field in enhancing seepage-leaching mass-transfer properties in in-situ leaching of uranium from low-permeability sandstone. We will provide an overview of the main factors influencing the in-situ leaching process in low-permeability ore layers, discussing the technical characteristics of applicable methods designed to enhance permeability in low-permeability uranium-bearing sandstone based on the existing research. Additionally, we will also explore the suitability of various approaches from other fields in the in-situ leaching of uranium process. Finally, we will outline the prospects regarding process methodologies, leaching agents, and enhancing permeability methods.