How is halite extracted from salt domes by underground mining?

Halite is extracted from salt domes using both underground mining and brine recovery methods. While brine solution mining involves drilling wells to dissolve the salt with water and pumping the resulting brine to the surface, traditional underground mining is also employed to extract halite directly.123

In underground mining, the most common system used for such deposits is room-and-pillar mining. In this process, a series of parallel drifts (tunnels) are driven into the salt deposit, with connecting drifts made at regular intervals. This creates a checkerboard pattern of rooms where the salt is extracted and pillars of salt that are left in place to support the overlying rock. In some cases, once mining reaches the boundary of the deposit, miners may remove some or all of these pillars to maximize recovery.4