Evaluation of the Hydraulic Recovery Potential in a Lake-Sourced Underground Mine Refrigeration System

Abstract

The foray of underground mines to ever deeper deposits has elevated mine refrigeration into an integral part of the operations. The air temperature limit, established through legislation, aims to ensure that workers in the mine are not exposed to temperatures extreme enough to cause heat stress. Because of the scale of refrigeration demanded by an underground mine, electricity/operating costs will constitute a significant portion of the budget. Using a lake for a cold-water source is a novel alternative to conventional refrigeration plants for subsurface cooling. The kinetic energy from the cold lake water flowing down the mineshaft can be harnessed with turbines, to reduce water pressure and produce usable energy. The scenarios examined includes ignoring the use of a turbine, using a turbine-generator combination, and using a turbine-pump combination. Considering the energy required to pump the return water from the bottom of the mine to the surface, the turbine-pump scenario is most economical. The scenario considering no turbine demonstrated the highest energy costs, while the turbine-generator combination was slightly less economical than the turbine-pump scenario.