DRILL MONITORING FOR GEOLOGICAL MINE PLANNING IN THE VISCARIA COPPER MINE, SWEDEN

When mining high grade, narrow ore bodies, the mining method often imp lies a very derailed knowledge of the ore contacts to avoid unacceptab le ore loss and waste rock dilution. During the past decade, the use o f microprocessor based drill monitoring equipment has become an accept ed technique even for percussive drilling. On the basis of the recorde d drill performance, such as penetration rate, torque pressure, thrust etc., a fast evaluation of the lithological sequence of the ore lone can be made. In order to evaluate the potential of percussive drill mo nitoring to provide detailed information of the geometry of the ore bo dy, the technique was tested in the Viscaria copper mine in Sweden dur ing 1996. To provide understandable information to the mine geologist, great emphasis was placed on the separation between the drilling resp onse generated by variations in rock conditions from variations caused by the operator and the drill system. Due to the complicated geology in Viscaria, the drilling response presented to the geologists was sep arated in two independent signals, one representing the hardness of th e rock and one representing the inhomogeneity (fracturing) of the rock . With those signals a good separation between different rock types in the ore horizon was achieved. The experience from the Viscaria copper mine is that drill monitoring not only can be used to locate contacts between rock types, but also to characterize rock conditions and, oft en, also to specify the exact rock type present Because it is possible to gel the drill monitoring information very quickly it is a valuable complement to diamond drilling for increasing the specific knowledge of the geology and the ore body.