ABSTRACT
This paper is aimed at addressing this challenge from a blasting perspective.
1.2 General practice
In the past 15 years, the large and/or deep mining operations in eastern Canada have tried many practices including collar casing for 1.0-1.5 m with plastic tubing, using a wooden wedge to protect the collar, adding a cohesive agent in drilling water to “glue” the cracked rock, and even pre-charging explosives in one or two rings adjacent to a to-becreated void, etc. However, amongst the tested methods, the most effective method is applying the mass blast principle thanks to the availability
1 INTRODUCTION
1.1 Background
With the booming business in natural resources in the past 10 years, the exploitation of minerals tends to reach more remote locations and/or at greater depth than ever. Consequently, it calls for mining technologies to deal with the harsh environment. In eastern Canada, most underground non-ferrous metals mines are getting deeper and deeper, reaching 3000 m below surface. The high level of horizontal stresses in the tectonic Canadian Shield plays a more important role in the design of mining sequences, stope dimensions, backfill and ground support methods. In drilling and blasting, technology development has been made in all aspects of the process-from drilling equipment for faster penetration and straighter holes to bulk loading of explosives in both down-holes and up-holes and to the application of electronic detonators, etc. For the end-users of such technologies, mining companies have also been active in the application of new technologies to address the new challenges.
