Block Caving

Block caving is a large-scale, low-cost underground mining method used to extract massive, relatively low-grade ore bodies, particularly in copper and other base-metal deposits. The technique relies on undercutting a block of ore so that gravity and induced stresses cause it to progressively fracture and collapse under its own weight. Broken ore is then drawn off through a network of tunnels and drawpoints beneath the caving zone, allowing continuous extraction without extensive drilling and blasting of each section. It is favoured for deep, high-tonnage deposits where open-pit mining becomes uneconomic due to depth or a high strip ratio. The method offers lower operating costs per tonne than many alternatives, making it attractive for bulk mining of orebodies with sufficient vertical extent and rock competent enough to cave predictably. However, it requires significant upfront capital investment and long lead times to develop the undercut and infrastructure before production ramps up. Accurate characterisation of the orebody and surrounding rock mass is critical to managing subsidence, dilution and caving propagation. Technologies such as muon tomography and other geophysical imaging tools are increasingly used to improve subsurface understanding and reduce exploration and planning risk associated with block caving projects. The method has been applied at numerous major copper and diamond operations worldwide and remains central to plans for accessing deeper mineral resources as near-surface deposits are depleted.