Cumberland zinc mine is part of a mining complex (Nyrstar Tennessee Mines) belonging to the company Nyrstar. This chamber and pillar type underground mine has a depth of about 500m. The deposit is located in paleo-karst in a host rock composed of limestone.
In some areas of the mine, the paleo-karst are still present and calcite, which was mobilized with zinc, is dissolved. Therefore, when opening galleries, major water inflows associated with the paleo-karst can cause problems. Also, the H2S content of groundwater is excessively high and areas where the water seeps require increased ventilation.
Our firm works in this mine since 2014. Various tests were carried out to understand the distribution of karsts, and in the meantime the water associated to these structure, and thus guide the mining operation and dewatering. Currently, some critical areas were identified and a dewatering program is still in analysis process.