Footprint and O&M Cost Reductions with Actiflo® System – A Pilot Study for Gold Mining Effluent Treatment

Stantec conducted an onsite pilot-scale feasibility study to confirm the effectiveness and efficiency of using an Actiflo® system for the mining effluent treatment. The main metal in the mining effluent stream include As, Sb, Cu, Pd, Mo, Ni, and Zn. Among these metals, Sb and Mo are the two major concerns. Currently, the mining effluent is treated with four reactors (ferric sulphate, lime, and polymer are added) in series followed by a clarifier.This study discussed various parameters to identify an optimized Actiflo® system, including treatment process configuration, chemical types and dosages, and reaction time. This study concluded that: i) coagulant needs to be added prior to pH adjustment for better Sb and Mo removal; ii) a reaction time of 8 min could be sufficient for co-precipitation process; and iii) both footprint and O&M cost could be significantly reduced with an Actiflo® system as compared to the current system.