Solution Mining
Another way to mine rock salt deposits is by solution mining(Figure 2.7). Hot water is pumped down the outer pipe into the salt deposits to dissolve the salt. The salt solution formed is known as artificial brine. This brine is then pumped up the inner pipe to the ground surface, where the brine is collected and stored in lakes until it is needed.
Upon the completion of solution mining in an area, the space left in the ground must be filled. If the space is not filled, the land above the space can collapse resulting in subsidence. The earth shifts downwards and can destroy roads and homes(Figure 2.8.)