Applying Geomechanics Principles to Mine Waste Management

摘要

Mining and mineral processing generate mine wastes including waste rock and spoil, coarse processing wastes, and fine-grained tailings. Waste rock comprises the unmineralised rock surrounding a hard rock metalliferous open pit mine. Spoil comprises the overburden stripped to expose coal on surface mining. Coarse processing wastes include scats and slag produced on the refining and smelting of metalliferous ores, and the coarse reject produced on the crushing and washing of run-of-mine black coal. Tailings comprise the ground residue left after the extraction of metal concentrates, the fine-grained wastes produced on the crushing and washing of black coal, and the residue produced on the refining of bauxite to produce alumina or the refining of laterite nickel ore to extract the nickel and cobalt. The coarse-grained wastes may be likened to weak to strong rock fill, and the tailings may initially be likened to a soil slurry that may solidify to be soil-like. Geomechanics principles may therefore be applied to the operational management and rehabilitation of mine wastes, ranging from rock to a rock flour. In so doing, the geotechnical engineering parameters and behaviour of stored mine wastes can be improved, providing the potential for enhanced post-mining land use and function, and reduced environmental impacts. The paper focusses on surface mines, and the surface or in-pit disposal and storage of mining and mineral processing wastes.