Underground Stope Blasting Design and Dilution Control
Longhole open stoping is a commonly used underground mining method applicable in moderate to steeply dipping orebodies in relatively competent ground. While longhole open stoping is generally not a selective method, the stope boundaries are designed to minimize dilution while maximizing ore recovery.
Stope stability is a key measure of longhole open stoping performance. Historically, stope stability analysis has focused primarily on geomechanic elements and rock engineering design approaches. However, even with robust, technically sound stope stability design campaigns, stope destabilization and overbreak continue to be frequent mine production challenges. Often, these instabilities arise from blast energy imparted to the surrounding rock mass, especially in the immediate hanging wall.
At RockEng, we provide world-class expertise with stope blast designs tailored to site-specific geomechanical characteristics of the rock mass to minimize stope wall damage and dilution.
We offer:
- Review of lithological/structural models to minimize unfavourable blast damage along geological/fault contacts.
- Collaboration with the mine planning team in reviewing and designing production blasts with an emphasis on dilution control.
- Robust drilling and blasting QA/QC programs to ensure appropriate execution of designed parameters.
- Design and review of blast vibration monitoring programs.
Contact us to find out how our blasting experts can add value to your longhole blasting projects.
Destress Blasting Design
Tunnel and underground mine development in high-stress conditions may be exposed to rockburst hazards. Rockburst risk management may include multiple hazard control and/or exposure management strategies. Rock mass preconditioning, such as destress blasting, is a tactical approach to hazard control by introducing blast-induced fractures into the rock mass. These fractures soften the rock mass and reduce potential stored strain energy.
At RockEng, our team of geomechanics and blasting experts provides services in evaluating the effect of rock mass destressing in burst-prone development headings and provides destress blasting designs customized to the rock mass conditions and stress state in each drift heading.
Destress blasting can also be applied to stope destressing where high-stress conditions may lead to challenges in production drilling, including drill hole squeezing/closures that require redrilling efforts.
We offer:
- Estimation of blast-induced explosive damage radius using empirical and numerical modelling tools.
- Design of destress blasting patterns for effective alleviation of rock burst potential in development headings.
- Design of panel destressing and curtain blasting for stope destressing in challenging ground.
