Optimized cooling systems for mining at extreme depths

Mining on the Witwatersrand in South Africa has workings at depths of 3800 m and detailed planning is laking place for very significant production at depths of 4000 m and more. Virgin rock temperatures will be in excess of 60 degrees C, and this, compounded by the great depth to which the ventilatio n must travel, creates extremely arduous cooling requirements. This paper addresses the optimum cooling systems required for such mines. T he main focus is on ice systems. The use of such systems, the history and s late-of-art of this technology, and the costs of providing ice-based coolin g systems are discussed.