Survey of Solution Mining for Uranium, Potash and Lithium
Solution mining is broadly defined as the extraction of raw material from deposits wherein the targeted minerals are dissolved by a lixiviant into solution. The loaded solution is pumped to a process plant for recovery into a saleable product. Other commonly used terms for solution mining are in-situ leaching (ISL) and in-situ recovery (ISR). This paper surveys the scope and nature of application of this approach to developing mineral deposits, with a focus on examples in Saskatchewan.
The practice of solution mining is well established in uranium, potash, lithium and other commodities, and its overall share of production is growing. In recent years, over half of primary uranium production comes from solution mines. About 40% of worldwide potash production is from solution mining. Roughly a third of lithium production is from solution mining and its share is likely to increase within this rapidly expanding market.
In terms of technical proficiencies, solution mining intersects hydrogeology with hydrometallurgy. An overview of hydrogeology as applied to solution mining, the range of lixiviants used to dissolve target minerals, and the advantages and disadvantages of solution mining compared to conventional mining are outlined.
The range of design features of uranium, potash and lithium mines around the world leads to more detailed descriptions of recent examples of solution mining in Saskatchewan. A greenfield uranium solution mine and process plant currently in detailed design, a recently constructed greenfield potash operation, and a demonstration stage lithium project are reviewed.
Lorne has 30 years of mineral processing experience, predominantly in uranium milling. He started his career in base metals in British Columbia. His first work in uranium was as a site metallurgist during commissioning and early operation of Orano’s McClean Lake mill. Next, Lorne spent a decade with Cameco in operations roles at Rabbit Lake and chief metallurgist at head office. Since then, he’s been engaged in engineering design for uranium and other commodities. His work at Wood’s Saskatoon office includes Denison - Wheeler River, Nexgen - Rook I, UEC - Roughrider, Paladin – Patterson Lake South, studies for Cameco and Orano, as well as international projects.
