Associate Professor/Program Leader/Principal Res Fellow
Centre for Mined Land Rehabilitation Sustainable Minerals Institute, the University of Queensland, Australia
Concerns about global liability of metal mine tailings have recently been heightened by the breach of the Mount Polley Cu-Au mine tailings (Canada) and the failure of the Fundão and Santarém mine tailings dam (Brazil). Rehabilitation of sustainable ecosystems covering tailings domains is an effective option to lower long-term environmental risks, but, its progress is rather slow and limited by current technology and practices to cap tailings by using conventional cover design, which are very expensive and variable environmental performance. Low-cost and direct phytostabilization has only achieved no more than “re-greening”, rather than non-polluting and ecologically sustainable outcomes, because of the pitfalls of applying “soil remediation” and hyperaccumulater plant species in the wrong context.
Tailings are nothing like soil, but wastes from processing hard rock ores of economic metals (e.g., Au, Cu, Mn, Pb, Zn, U) and industrial mineral deposits (e.g., coal, phosphate, bauxite), which are largely composed of often ultra-fine gangue containing waste minerals containing high levels of metals, metalloids, salts, acidity/alkalinity and other polluting factors. The present talk will illustrate emerging innovations in tailings rehabilitation by using recent findings from our research with tailings of magnetite, copper, and lead-zinc mines and bauxite refineries. Technological pathways are proposed for tailings of different mineralogy, within the framework of pedogenesis and geomorphology.