Stripping Ratio (SR)
Compute the stripping ratio (SR) of an open-pit mine by dividing the amount of waste (worthless rock that must be removed) by the ore extracted. It is the central economic indicator of open-pit mining: the higher the SR, the more useless material is moved per tonne of ore, and the higher the cost. It defines the pit limit and the viability of the operation. Enter the waste and ore quantities.
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Stripping ratio (SR)
In an open-pit mine, getting to the ore means first stripping away the 'cap' of worthless rock that covers it — the waste, or overburden. The stripping ratio (SR) measures that effort: how many tonnes of waste have to be removed for each tonne of ore mined. It ranks among the numbers that weigh most heavily on mine economics, since every tonne of waste has to be drilled, blasted, loaded and hauled to the dump without generating any revenue. The stripping ratio climbs as the pit deepens, and the point at which it makes mining unviable defines the economic pit limit. Above a certain stripping ratio, switching to underground mining pays off. Enter the quantities of waste and ore.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.