blockcaving

Block caving is a large-scale underground mining method used to extract massive ore bodies. It relies on gravity to break and transport the ore. The process begins with drilling and blasting a large undercut beneath the ore body. This undercut creates a void, weakening the overlying rock.

Once the undercut is established, the weight of the ore body above causes it to fracture and collapse under its own weight. The fractured ore then falls into the undercut. Drawpoints, which are tunnels or openings beneath the undercut, are established to allow the broken ore to be extracted.

As ore is drawn from the drawpoints, the overlying rock continues to collapse and break, feeding more ore down. This process continues until the entire ore body is extracted or it becomes uneconomical to continue. Block caving is known for its low operating costs per tonne of ore due to the use of gravity and large-scale automation.

However, it requires significant upfront capital investment for development and infrastructure. The method is best suited for large, competent, and relatively homogenous ore bodies. Careful planning and management are crucial to ensure the cave propagates as intended and to maintain safety. Environmental impacts are generally minimized compared to open-pit mining due to the underground nature of the operation.