Large Underground Blast At Inco Using Slurry Explosives

CIM Bulletin, Vol. 71, No. 792, 1978

P. F. Venus, Mine Superintendent, Creighton No. 3 Mine, Inco Metals Company, G. W. Johnston, Superintendent of Industrial Engineering, Mines and Mills, Inco Metals Company

In December 1977, a large pillar was removed by blasthole mining methods at Inco's Creighton No. 3 mine. Although the 2,363,000-ton blast was not a size record for a single underground blast at Inco, it did represent a significant departure from conventional blasthole mining. In terms of the application of nominal 6-inch-diameter boreholes underground, coupled with bulk slurry explosives, the magnitude of the blast is considered a first and very important development. The application of large-diameter boreholes in underground operations was first tried successfully in 1973. Since that time over PA million feet have been drilled in this adaptation of an open-pit technique to underground operations. The blast, which required 708 holes, totaling 131,500 feet of drilling, was loaded in a six-week period, using special slurry handling techniques developed jointly by Inco and CIL. Inco operating and engineering personnel consider this application of large boreholes and slurry explosives for blasthole mining a very important milestone in modern mining technology.
Keywords: Underground mining, Blasthole mining, Inco, Explosives, Slurry explosives, Creighton mine, Drilling, Pillar blasting, Ventilation, Vibration monitoring.