In this article, we explore two types of mining: coal mining and hard rock mining. Although both employ surface and underground methods, they differ significantly due to the materials they target.
Coal Mining
Coal mining focuses on extracting sedimentary rock rich in carbon, hydrogen, and oxygen, which is softer and occurs in layers. This type of rock formation, known as coal seams, varies in thickness and depth, influencing the mining method used.
Coal mining can be conducted through two main methods:
Underground Mining: Also known as deep mining, this method involves creating tunnels deep into the earth to access coal seams located underground. It is employed when coal deposits are located at considerable depths that cannot be accessed efficiently through surface mining alone. Underground mining methods can vary, including longwall mining, where a long wall of coal is mined in a single slice, or room and pillar mining, which involves leaving pillars of coal to support the roof while the remaining coal is extracted.
Surface Mining: Surface mining methods are used when coal deposits are relatively close to the earth’s surface. This includes strip mining, where layers of soil and rock above the coal seam are removed in strips, and open-cast mining, which involves the use of equipment, such as draglines and shovels to scrape away layers of soil and rock to expose coal deposits beneath the surface. Surface mining is often used for coal seams that are shallow and extensive.
Uses
Electricity Generation: Thermal coal is burned to generate electricity in power plants.
Steel Production: Metallurgical coal is a key ingredient in the steel-making process, providing the carbon necessary for steel production.
Heating: Coal is also used for residential and commercial heating purposes in some regions.
Hard Rock Mining
Hard rock mining targets minerals found in solid, harder rock formations.
Methods for hard rock mining typically involve:
Drilling and Blasting: This method involves drilling holes into the solid rock and inserting explosives to create fractures and openings. The blasting breaks the rock into smaller pieces, making it easier to extract the ore. This technique is essential for accessing hard rock deposits deep within the earth.
Underground Mining: This includes several techniques:
Shaft Mining: Vertical tunnels, or shafts, are dug deep into the ground to reach ore bodies. Miners use elevators to travel up and down the shafts, accessing horizontal tunnels (drifts) at different depths where the ore is extracted.
Drift Mining: Horizontal tunnels, or drifts, are created to follow the vein of ore. This method is often used when the ore body is located along a horizontal plane.
Room and Pillar Mining: In this method, rooms of ore are extracted while leaving pillars of rock to support the mine roof. It is used for flat or gently dipping ore bodies.
Open-Pit Mining: This method involves excavating large open pits or quarries to reach mineral deposits close to the surface. It is used when the ore body is extensive and near the surface, allowing for the removal of large quantities of rock and ore. Open-pit mining uses heavy machinery like drills, trucks, and loaders to move the extracted material.
Uses
Precious Metals: Such as gold, silver, and platinum.
Base Metals: Including copper, zinc, lead, and nickel.
Industrial Minerals: Used in construction, electronics, and manufacturing.
Conclusion
Mining’s role in our daily lives is extensive and essential, yet it often operates behind the scenes, unrecognised by many. From providing the materials that build our homes and power our devices to supporting advancements in healthcare and agriculture, mining shapes modern existence in profound ways. Equally important are the jobs it creates worldwide. As we strive for sustainable practices and greater transparency in resource extraction, understanding the intricacies of mining fosters a deeper appreciation for its impact on global development and the livelihoods it sustains.