Development of a correlation between rotary drill performance and controlled blasting powder factors

CIM Bulletin, Vol. 75, No. 844, 1982

JOHN C. LEIGHTON, Graduate Student, and C.O. BRAWNER, Professor, Department of Mining and Mineral Process Engineering University of British Columbia, DOUG STEWART, Chief Engineer, Afton Operating Corporation, Kamloops, B.C.

Despite the availability of established, sophisticated methods for planning and designing stable slopes in rock, comparatively little attention is usually paid to the problems of carrying out the excavation. Blasting should be carefully planned to obtain optimum fragmentation as well as steep, stable working and final pit walls. The principal difficulty facing a blast designer is the lack of prior information about the many critical blasting characteristics of the rock mass. The common practise of trialand-error blasting will eventually lead to a suitable program, but must be repeated time after time in variable geology. This frequently results in many blast-damaged slopes. Recent research indicates that monitoring drill performance will yield a Rock Quality Index which correlates to a Powder Factor value. The drilling can provide a continual supply of data, reflecting changes in the rock mass which enables the selection of an economical powder factor.
Keywords: Open-pit mining, Drilling, Blasting, Powder factors, Rock mechanics, Slope stability, Rock quality index, Afton deposit.