Evaluating CO2 storage capacity in Queensland mine tailings: a reactive transport modelling study

Mining operations in Australia generate large volumes of waste, which increases the risk of acid and metalliferous drainage (AMD), contributing to environmental pollution and high carbon emissions. The challenge lies in managing this waste sustainably while reducing the carbon footprint, which is significant, as traditional methods for waste treatment (such as the addition of limestone – CaCO3 for AMD treatment) can be carbon-intensive. Current research on mineral carbonation (Fig. 1)—a technique that locks CO₂ into stable minerals like carbonates—mainly targets ultramafic wastes from nickel, platinum, or diamond mines, which are scarce in Queensland. This leaves a gap for gold and copper operations, common in Queensland, where tailings from sites like Croydon hold untapped potential for CO₂ sequestration.