While working in an Northern Ontario underground nickel mine in the 90’s, a problem arose that required the invention and design of a methodology using a shear line that could secure the integrity of a hanging wall (Norite) at the contact of an orebody where impurities were located. These impurities would affect the milling operation when mixed in with ore.
For evaluating the use of blasting operations themselves as potential replacement for underground crushers, a new blasting model was developed and is explained in the following article. The model is unique in that it takes into account three cases shown here; CASE 1 - shock velocity is less than the explosive detonation velocity (supersonic) of an explosive, CASE 2 - shock velocity is equal to the detonation velocity (sonic) of an explosive, CASE 3 - shock velocity is greater than the detonation velocity (subsonic) of the explosive product. The unit charge model provides an ability to compare explosives and rock/ore types together with pattern geometries for the purpose of implementing specific blasting pattern designs that are effective for the amelioration of crushing costs in underground mines with the intent to replace primary crushers altogether.
The ultimate goal of underground ring blasting is to extract ore while minimizing dilution. The AEGIS 3D design software has re-invented traditional methods of blast design by using a dynamic model to visualize potential damage around a blast hole from an explosive blast.
Keep informed about Aegis Break Analyzer, the breakthrough technology that has triggered global success. Chris Preston, P. Eng. and Vice President of Research and Development, speaks on how the software had optimized mine drilling and blasting and diminished reliance on expensive underground crushers.
Initiating a detonator sensitive explosive with a detonating cord placed along the length of the charge yields false detonation velocity measurements using traditional means. Higher velocity readings are registered using VOD probes. The fact is that axially initiated explosives yield significantly lower velocities if the vector sum of the velocity is accounted for. This article will detail the proper measurement methodology and outline the reason axial initiation should not be used for production ring blasting outside of pre-shear/pre-split designs.
Discover the four-component break model that is transforming the blasting industry by eliminating the need for crushing operations and examine how it was used to decrease stope damage, reduce dilution, and eliminate overbreak in Goldcorp’s Eleonore gold mine.