摘要
Abstract: Where an ore deposit is relatively impermeable to fluid flow, some method of artificial enhancement of permeability will be necessary if leach mining is to be employed to recover the metal. Factors influencing recovery of metals in these circumstances are closely matched by the factors encountered in the recovery of geothermal energy by Hot Dry Rock (HDR) technology, which introduces water as a heat exchange medium to extract heat from naturally fractured rocks which otherwise do not contain enough natural water for conventional hydrothermal heat extraction. HDR technology inevitably involves artificial enhancement of the permeability of the rock heat exchanger, known as the geothermal 鈥榬eservoir鈥? This enhancement is achieved by 鈥榮timulating鈥?or 鈥榟ydraulically fracturing鈥?the natural rock joints, using fluid injection at high pressure. The Camborne School of Mines team carried out experimental work on HDR technology in Cornwall, UK, over a period of fifteen years, backed up by mathematical modelling of the reservoir stimulation, and developments in geophysical and geochemical monitoring of the geothermal systems created. CSM Associates Ltd possess the accumulated experience of this programme, and are currently involved directly in HDR experimental projects in Europe and Japan. It is proposed that this HDR experience should be applied to leach mining investigations, aimed at exploring the possibilities of transferring the HDR technology from geothermal heat recovery to metal recovery directly from ore deposits, without the necessity for conventional mining operations.