Alternate methods of energy recovery for the mining industry

When mining for certain precious metals such as gold and silver, it is sometimes necessary to excavate to great depths (>3000 m) below the surface, where the environments is hot and humid. Refrigeration plants are needed that require large volumes of cooling water to be brought into and taken out of the mines. By converting the potential energy of the incoming water to electricity rather than to heat results in cooler mine temperatures and less need for off-site power. The objective of the project was to demonstrate the technical and economic viability of energy recovery from the incoming cooling water used in the refrigeration systems. The economic, operational, and logistic constraints imposed by a mining operation where ore production, not power production, is the primary concern were addressed. The final design was an impulse turbine-generator machine rated at 300 kW output at 820 m head and 40 1/s flow rate