Underground Mining: Mine Life: - Underground mines typically last longer than open pit mines because they can access deeper ore deposits, have continuous orebodies at depth, and allow for selective mining of high-grade zones. Mining Methods: 1. Room and Pillar Mining: Leaving rooms while extracting ore pillars to support the roof. Common for coal and salt mining. 2. Longwall Mining: Extracting long panels of coal or ore in a single slice. Efficient for coal and sedimentary deposits. 3. Cut and Fill Mining: Mining horizontal slices of ore and filling voids with waste material. Suitable for irregular ore bodies. 4. Sublevel Caving: Blasting ore to collapse under gravity into a collection point. Suitable for large, uniform ore bodies. 5. Block Caving: Allowing ore to collapse under its weight. Suitable for large, low-grade ore bodies. 6. Shrinkage Stoping: Mining horizontal slices with collapsing roofs. Suitable for narrow, steeply dipping ore bodies. 7. Room and Pillar with Retreat Mining: Combining room and pillar mining with retreat mining to extract more ore. Open Pit Mining: Mine Life: - Open pit mines generally have shorter mine lives due to high stripping ratios, infrastructure costs, and environmental regulations. Mining Methods: 1. Bench Mining: Developing in horizontal layers, progressing downwards. 2. Strip Mining: Removing overburden to expose the ore body. Common for surface deposits. 3. Quarrying: Extracting construction materials like limestone and granite by drilling and blasting. 4. Placer Mining: Extracting minerals from loose sediments like sand and gravel, often for gold and platinum. 5. Heap Leaching: Extracting metals from low-grade ore by applying a leaching solution. 6. Dredging: Extracting minerals from underwater deposits using specialized equipment.