Work out mine stripping ratio instantly with clear inputs, formula shown and shareable results.
Stripping ratio is tonnes of waste moved per tonne of ore. It drives open-pit economics directly: at a ratio of 3.4 to 1, waste haulage is the majority of mining cost even though it generates no revenue. The break-even stripping ratio is the point where an extra tonne of ore no longer pays for the waste needed to reach it.
Stripping ratio
SR = waste tonnage / ore tonnage
Mining cost per tonne of ore
Cost = (waste x waste cost + ore x ore cost) / ore tonnage
The break-even stripping ratio. As the pit deepens the incremental waste per tonne of ore rises until the marginal ore no longer covers the stripping cost, which defines the ultimate pit shell.
When stripping ratios rise beyond roughly 8-12 to 1 for typical deposits, though the crossover depends on ore value, geometry and ground conditions.