In-situ leaching (ISL), also called in-situ recovery (ISR) or solution mining, is a mining process used to recover minerals such as copper and uranium through boreholes drilled into a deposit, in situ. In-situ leach works by artificially dissolving minerals occurring naturally in the solid state.
The process initially involves the drilling of boreholes into the ore deposit. Explosive or hydraulic fracturing can be used to create open pathways in the deposit for the solution to penetrate. Leaching solution is pumped into the deposit where it comes in contact with the ore. The solution bearing the dissolved ore content is then pumped to the surface and processed. This process allows the extraction of metals and salts from an ore body without the need for conventional mining involving drill-and-blast, open-cut or underground mining.