breasting

Breasting, or breast stoping, is a mining technique where ore is extracted from a nearly vertical face. This method is employed in underground mining, which is utilized when ore bodies are located deep below the surface, making surface mining economically unfeasible.12

Underground mining is generally more expensive per ton than surface mining due to smaller equipment and limited access, resulting in lower productivity. However, it offers the advantage of mining only ore, unlike open-pit operations that often remove significant amounts of waste rock. The choice of underground mining method, including stoping techniques, depends on factors such as the ore body's size, shape, orientation, rock strength, and depth.2

Stopes are the openings created during ore extraction. The process involves development (preparing ore blocks) and production (stoping). For steeply dipping ore bodies, methods that utilize gravity for ore movement are considered. Rock mechanics plays a crucial role in understanding how underground openings interact with the surrounding rock mass, especially at great depths where immense pressure can lead to rock bursts.2