A perimeter blasting is a special blasting technique to achieve a profile closer to design than normal production blasting would (Blasting Principles, n.d.). The main purpose of perimeter blasting is to lessen blasting operations’ damage to the final excavation perimeter, such as mine walls or tunnel faces. This is accomplished by limiting the concentration of explosive energy and avoiding overbreak or excessive fracture outside of the intended excavation lines. This method lowers the need for expensive post-blast cleanup and support, enhances stability, and lessens damage to the nearby rock.
Perimeter blasting offers several advantages such as:
Minimizing overbreak and backbreak
Perimeter blasting helps reduce overbreak (excessive rock breakage beyond the intended boundary) and backbreak (fractures extending into surrounding rock). This ensures clean-cut walls, reducing the need for additional excavation or reinforcement (Underground Perimeter Control Basics, n.d.).
Enhancing safety
Uncontrolled blasting can lead to unstable ground conditions, increasing the risk of rock falls and accidents. Perimeter blasting mitigates these risks by controlling the stress exerted on the surrounding rock, improving stability and reducing fatalities associated with poor blasting techniques (Dindarloo et al., 2015).
Reducing dilution
Dilution occurs when non-ore material mixes with ore during excavation, lowering the overall value of mined material. Perimeter blasting minimizes this by preventing unwanted material from entering the muck pile.
Cost efficiency
By reducing overbreak and backbreak, perimeter blasting lowers downstream costs related to mucking, trucking, bolting, meshing, and ventilation. It also decreases drilling time and costs compared to conventional methods.
Reference
Blasting Principles. (n.d.). Retrieved April 14, 2025, from https://www.orica.com/products-services/resources/blasting-principles
Dindarloo, S. R., Askarnejad, N.-A., & Ataei, M. (2015). Design of controlled blasting (pre-splitting) in Golegohar iron ore mine, Iran. Mining Technology. https://doi.org/10.1179/1743286314Y.0000000077
Underground Perimeter Control Basics. (n.d.). Thoroughbred Drill and Blast Consultants. Retrieved April 14, 2025, from https://tbredblast.com/posts/ugperimetercontrol1
