A controlled blasting approach to dilution control in narrow-vein mining

A dilution control program was implemented at Campbell Mine in 2000 in response to concerns of increasing dilution levels. The initial objective of the program was to develop design guidelines for reducing unplanned dilution by 15%.; A benchmarking study was performed to identify critical causes of dilution and promising control methods. Controlling blast vibrations was found to have the greatest potential for easy-win techniques of reducing dilution; a blast-monitoring program was implemented to measure ground vibrations during production blasts.; Vibration analysis included assessment of firing times and peak amplitudes, as well as calculation of scaled distance parameters. Stope and blast design guidelines were developed to keep vibration levels under the critical level of 2400 mm/s, and provide a significant tool in dilution control.