TTis study explores the use of backffll in hard rock bord-and-pillar mines to increase the pillar strength and extraction ratio at depth. TTe use of backffll will also minimize the requirement for tailings storage on surface and the risk of environmental damage. A literature survey indicated that backffll is extensively used in coal mines, but rarely in hard rock bord-and-pillar mines. To simulate the effect of backffll conffnement on pillar strength, an extension of the limit equilibrium model is proposed. Numerical modelling of an actual platinum mine layout is used to illustrate the beneffcial effect of backffll on pillar stability at greater depths. TTe magnitude of conffnement exerted by the backffll on the pillar sidewalls is unknown, however, and this needs to be quantiffed using experimental backffll mining sections equipped with suitable instrumentation.
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