What is a stripping ratio in coal mining?

In the context of coal mining, a stripping ratio is a critical metric that represents the amount of waste material, or overburden, that must be removed to extract a specific quantity of coal.1

This ratio serves as a vital tool for mine operators to determine the economic feasibility of a project. It helps calculate the precise point at which it becomes necessary to switch from surface mining to underground mining, as the cost of removing increasingly thick layers of strata can eventually outweigh the value of the coal being recovered.1

For a more comprehensive cost-benefit analysis, the stripping ratio can also incorporate the current selling price of coal and a minimum profit margin added to the total cost of production. If the break-even stripping ratio remains favorable, mining operations can continue; if not, alternative methods such as underground mining or augering may be required to access the remaining reserves.12