Estimating the effect of blast and ventilation parameters on blast fume dilution time in underground development blasting using computational fluid dynamics

Abstract

ABSTRACT In underground mining, blasting-induced pollutants are diluted and exhausted out of the working area using the auxiliary ventilation system, which can account for up to 50% of the total mine ventilation electricity consumption. Few detailed studies have been published on the mechanisms and the dilution efficiency of forcing, exhaust, and overlap ventilation systems. To date, no systematic investigation has considered the effect of important factors, such as porosity, muckpile profile, type of explosives, and humidity on the post-blast dilution time. This research seeks to address these issues and make post-blast dilution time estimation more accurate and realistic. Numerical models were developed using computational fluid dynamics software to simulate blast fume dispersion and clearance in an underground development heading. Phase 1 study results show that on average, the time to reach the permissible exposure limit is approximately five-fold faster for the forcing system than the exhaust system and slightly more efficient than the overlap system. Phase 2 study results show that the porosity of the muckpile and explosive type have a significant impact, the muckpile profiles have an inverse effect, and the relative humidity has little to no impact on dilution time at lower temperatures (~0–30°C).