Oxygen consumption in a northern Canada tailings storage facility
Oxygen consumption from sulphide mine tailings was measured under a partial thermal granular cover in a Northern Canada tailings storage facility. The reclamation concept for the filtered-pressed tailings uses permafrost to maintain the tailings in a permanent frozen state by use of a thermal granular cover. The decrease in the oxygen concentration in a sealed chamber at the tailings – cover interface allowed to calculate the oxygen flux at the tailings surface using fundamental gas diffusion laws. The average measured oxygen flux at the tailings surface was 47 moles / m² / year, an 83% decrease over previous data collected on uncovered tailings. Despite the decrease in the oxidation rate, oxidation still takes place under the partial cover. This initial use of the testing apparatus will allow refinement of the testing method for future measurement campaigns.