Blast damaged zone influence on water and solute exchange between backfilled open-pit and the environment

ABSTRACT: In-pit disposal of mine wastes is a promising alternative management approach to conventional disposal facilities. However, wastes disposed of in pits are in direct contact with the surrounding rock, and regional groundwater could flow in the wastes and contribute to contaminant dispersion in the environment. Blasting operations result in the creation of new fractures close to pit walls, which can provide preferential flow paths and divert flow around backfilled masses, thus reducing contamination risks. The present study aimed to investigate the influence of the blast damage zone (BDZ) on water and solute exchanges using 3D numerical modelling. Results highlighted the BDZ potential beneficial effect which could reduce the flow rate though backfilled tailings by 40% and decrease contaminants release rate in the environment by around 30%. This paper presents the BDZ simulation approaches and discusses the main results obtained.