Apart from deep shaft mining, there are several other types of underground mining methods. Some of the commonly used methods include:
- Room and Pillar Mining: This method involves the extraction of minerals by creating a network of rooms within the deposit, leaving pillars of mineral or rock to support the roof. The rooms are typically arranged in a grid pattern, and the extraction process can be carried out by various equipment, such as continuous miners or drill and blast techniques.
- Longwall Mining: Longwall mining is a highly productive method used for the underground extraction of coal. It involves the use of a longwall shearer, which is a specialized machine that cuts and removes the coal along a long face or wall. As the machine advances, hydraulic supports, known as shields, are used to provide roof support.
- Cut and Fill Mining: Cut and fill mining is a method used for mining ore deposits with steeply dipping or irregularly shaped veins. It involves the excavation of horizontal or inclined slices (cuts) into the deposit. The extracted ore is then removed, and the resulting void is filled with backfill material, such as waste rock or cemented tailings.
- Sublevel Caving: Sublevel caving is a bulk underground mining method commonly used for large-scale mining of low-grade or disseminated ore deposits. It involves the extraction of ore through a series of sublevels, where the ore is blasted and allowed to cave under its weight. The broken ore is then collected through drawpoints at the bottom of the cave.
- Block Caving: Block caving is a method used for large-scale mining of massive ore deposits. It involves the extraction of ore by undercutting or removing a large block of the ore deposit, causing it to break and cave under its weight. The broken ore is then collected through drawpoints at the bottom of the cave.
- Retreat Mining: Retreat mining is a method used to extract the remaining coal pillars or pillars of other minerals after the initial extraction has taken place. It involves the deliberate collapse or retreat of the mined-out area, allowing the extraction of the remaining pillars. This method can be challenging and requires careful planning to ensure the safety of the miners.
Each underground mining method has its advantages and considerations, depending on the type of deposit, the nature of the ore, and the desired production output. The choice of method is based on factors such as geology, economics, safety, and environmental impact.