Valorisation of acid mine drainage treatment sludge as remediation component to control acid generation from mine wastes, part 2: field experimentation

摘要

The possibility of using acid mine drainage (AMD) treatment sludge as a cover component to control AMD generation from mine wastes was investigated in the laboratory (companion paper). The results showed that mixtures of sludge and waste rock, and sludge and tailings may be integrated in an AMD prevention and control strategy at Doyon mine site (northwestern Quebec, Canada). To further tests these scenarios in realistic climatic condition, instrumented field test cells were installed on site to evaluate the performance of the mixtures to control AMD generation from tailings and waste rock under natural field conditions. The observations of two seasons of monitoring are presented in the paper. The waste rock-sludge mixture placed over waste rock was able to reduce the generation of AMD from the waste rock, and was able to produce a neutral effluent with low concentrations of dissolved metals. The tailings-sludge mixture placed over tailings, with an evaporation protection layer, maintained a high volumetric water content and reduced sulphide oxidation from the tailings. Monitoring of the field cells will continue to provide valuable information on the possible sludge valorization options.