Mining is one of the oldest industrial pursuits on the planet. It is the extraction of commercially valuable resources from under the earth’s surface, such as gold, coal, and gemstones. In reaction to the harmful effects on mining employees and the environment, modern mining technology have evolved. This new technology, together with economic advancements, has considerably enhanced safety. Surface and subsurface excavation of soil and rock is generally required in mining to get access to the resources of interest. Surface mining is more frequent than subterranean mining owing to the ease of access. It is estimated that 85 percent of minerals mined in the United States are extracted from the earth’s surface. Placer deposits are extracted from river, beach, and ocean sediments. Lode deposits are found in geologic intrusions or veins inside a mass of soil or rock.
The key minerals are extracted and processed from the ore. Gravity is used to separate the components in the processing of placer ore material. Sluice boxes, also known as shakers, are used to separate the components. Crushing and pulverizing lode ore is required for the extraction of precious minerals. Both forms of ore are finally processed mechanically or chemically. Removal of materials that exist in minute amounts, such as rare earth elements, is accomplished by in-situ leaching, which use water or acidic and basic solutions to remove the substance without excavation.
Surface mining requires mining separation and solutions for overlaying layers of soil and bedrock in order to get access to mineral reserves. The most common processes are open-pit and strip mining, quarrying, and mountaintop removal. Subsurface mining is accomplished by subsurface excavation using both human and machine techniques. To reach subterranean mineral reserves, access tunnels and shafts are built. The kind of access or extraction method used in subsurface mining is determined by the type and hardness of the rock to be extracted. Access might be either horizontal, slanted, or vertical. Drift mining abhors horizontal tunnels, whereas slope mining employs diagonally sloping shafts. Shrinkage stope mining provides a sloping subterranean chamber; room and pillar mining is an excavation method that permits safer access to the ore. Room and pillar mining is combined with retreat mining, in which pillars are removed, allowing for a controlled cave-in that loosens more ore without the need for labour. Longwall mining exposes a large amount of ore.
Surface mining gear includes wheel loaders, excavators, dump trucks, bulldozers, and motor graders. To transport materials from the mine, articulated dump trucks and other cutting tool equipped gear, such as continuous and longwall miners, as well as shuttle vehicles, are used. Hydraulic mining removes large amounts of dirt and rock by spraying pressured water from hoses.