solution mining

Solution mining is a method used to extract soluble minerals from the ground by dissolving them in a liquid and then pumping the resulting brine to the surface. This technique is employed for minerals like halite (rock salt), potash, and trona.1

The process involves drilling a borehole into the mineral formation. Water is then injected, dissolving the minerals. The resulting mineral-rich brine is extracted through the same or a different borehole, creating underground caverns. This method is crucial for producing large quantities of salt, as well as extracting bromine, lithium, and boron from natural brines. In some cases, like with gold, a process called cyanide leaching is used, which can cause significant environmental pollution and generate large amounts of waste.12