Stripping ratio

In mining, stripping ratio or strip ratio refers to the ratio of the volume of overburden (or waste material) required to be handled in order to extract some volume of ore. For example, a 3:1 stripping ratio means that mining one cubic meter of ore will require mining three cubic meters of waste rock. Stripping ratios are typically reduced to show the volume of waste removal required to extract one unit volume of ore, for example, 1.5:1 as opposed to 3:2.