Salt exploitation by dissolution – an alternative method to reduce post-closure risks

During the last century, the mine closure frequency had significantly increased, therefore important environmental issues affect the public safety and the sustainable development process of the mining areas. The customary method of salt exploitation by dissolution uses the flooding of the formed caverns as the last step of the exploitation, which permanently isolates the caverns. In this case the rock-mass equilibrium inside the cavern changes, calamities such as seismicity, subsidence and collapse occasionally occur. Quite a few times, human settlements, civil buildings or industrial constructions located at the surface are affected. The present paper discusses adopting an alternative salt exploitation method by dissolution which offers the possibility to extract the entire salt deposit. This allows monitoring the stability factors linked to the exploitation process - the collapse that will occur as monitored represents the latter part of the method. It finally offers the opportunity to reclaim the water surface formed as a sustainable development goal and to reduce the long-term risks for calamities.