Drill monitoring for geological mine planning in the Viscaria copper mine, Sweden

CIM Bulletin, Vol. 90, No. 1014, 1997

Håkan Schunnesson, Division of Applied Geology, Luleå University of Technology, Luleå, Sweden, and Kirsten Holme, Viscaria AB, Kiruna, Sweden

When mining high grade, narrow ore bodies, the mining method often implies a very detailed knowledge of the ore contacts to avoid unacceptable ore loss and waste rock dilution. During the past decade, the use of microprocessor based drill monitoring equipment has become an accepted technique, even for percussive drilling. On the basis of the recorded drill performance, such as penetration rate, torque pressure, thrust etc., a fast evaluation of the lithological sequence of the ore zone can be made. In order to evaluate the potential of percussive drill monitoring to provide detailed information of the geometry of the ore body, the technique was tested in the Viscaria copper mine in Sweden during 1996. To provide understandable information to the mine geologist, great emphasis was placed on the separation between the drilling response 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 separated in two independent signals, one representing the hardness of the 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, often, also to specify the exact rock type present. Because it is possible to get 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.
Keywords: Drill monitoring, Geology, mine planning, Viscaria copper mine.