Mineral Economics, Mine Planning, Systems Engineering · Mine Planning · 2 marks · Numerical answer
A ringhole round targets2500 tonnes at8% metal but breaks only90%. Overbreak adds250 tonnes of wallrock at0.5% metal. If95% of the resulting muck is recovered, find recovered metal in tonnes to two decimals.
Broken ore contributes2500×0.90×0.08=180 tonnes metal. Wallrock contributes250×0.005=1.25 tonnes. Apply95% recovery to the combined181.25 tonnes:0.95×181.25=172.1875, or172.19 tonnes. Recovery is applied after combining the two metal contributions.