Open pit mining, also known as open-cast or open-cut mining, is a surface mining method used to extract minerals located relatively close to the surface by removing overlying waste rock and soil to expose and excavate the ore body from a large, terraced excavation. This method is widely used across bauxite, gold, iron ore, and diamond mining because many of these deposits occur in laterally extensive or near-surface formations suitable for bulk extraction. The pit is typically developed in a series of benches or steps, each with a defined height and slope angle determined by geotechnical analysis to ensure wall stability, with haul roads constructed to allow trucks and other equipment to move material from the pit floor to processing facilities or waste dumps. Open pit operations rely on drilling and blasting to fracture rock, followed by loading with excavators or shovels and hauling via large dump trucks, conveyor systems, or rail. Compared to underground mining, open pit methods generally allow for higher production rates, lower per-tonne operating costs, and easier access for large equipment, though they require management of larger waste rock volumes, dust, noise, and progressively deeper pits that increase haulage distances and stripping ratios over the life of the mine.
