A mine is a place that is accumulated from all kinds of metal ores and rare materials that have economic value. Mining or mining is the act of extracting valuable minerals or other materials from the ground and usually from mines.
Mining is the extraction of valuable minerals and other materials from the ground and mines. Some minerals that are obtained from deposits, for example: metal ore, coal ore, oil shale, types of precious stones, diamond, limestone, ornamental stone, salt rock, gold, silver, potash, sand, clay.
The process of mining is any type of material that cannot be grown and obtained through agricultural processes, or produced artificially in a laboratory or factory, and a more complete definition of mining is the extraction of any non-renewable resource such as oil, natural gas or even water.
Metal and stone extraction has been done by humans since prehistoric times. The stages of modern mining include exploration and exploration, analysis of the profit of extracting the desired minerals and the final restoration of the land after the completion of the extraction.
Mining in mines, both during the active period and after its closure, usually creates destructive effects on the environment. For this reason, most countries in the world have adopted regulations to reduce these negative effects. Also, work safety has been a concern for a long time, and modern methods have significantly improved safety in mines.
Mines are divided into two general categories:
1- معادنsuperficial or apparent, minerals that are on the surface of the earth, its acquisition does not require exploration, such as ruby, stone, surface bitumen, oil, salt, sulfur, millstones, soil
2- Deep or esoteric mines, which exist in the depths of the earth and its achievement requires a process of hard work and effort, such as: gold, iron, copper, lead, crystal and turquoise, nickel…
Each of the above mentioned categories has various sub-sets which are classified according to the mineral form and type of deposit. Another type of classification of mines includes the type of mineral which is divided into coal and non-coal.
In surface mining, to obtain its main reserves, the surface covering of plants, mud and, if necessary, rock layers are removed. Surface extraction techniques are:
1- Open-pit mining, in which materials are extracted from an open pit in the ground.
2- Mining in stone mines (quarrying), which is the same method as open pit mining, the only difference is that it refers to sand, gravel, stone and soil mines.
3- Extraction in the form of a vein (strip mining), includes separating the outer layers of the surface to expose ores or underground cracks;
4- Mountaintop removal, which in such cases is usually done for coal extraction, and this also includes removing the mountaintop to reach the mineral deposit that is deep in the ground. But most of the placer deposits (but not all), due to their shallowness, are extracted with surface methods.
In mines, subsurface mining involves digging tunnels or shafts into the ground to reach rock deposits. All kinds of stones for processing and waste slabs for disposal are transferred to the ground through these tunnels and shafts.
Subsurface mining can be classified according to the shape of the access shafts, and the mining methods or practices used to reach the mineral deposit:
1- Horizontal access tunnels are used in horizontal mining (drift mining).
2- In slope mining, sloping access shafts are used.
3- Vertical access shafts are used in shaft mining.
Extraction in hard and soft beds requires different techniques and methods. Other methods include:
– Shrinkage stoping mining, upward and upward mining, and creating underground storage chambers
– Longwall mining, which means crushing the surface of a long ore underground
– Room and pillar mining, in which tunnels are dug and pillars are created to support the roof. After chamber and column ore is mined, retreat mining is often performed, in which the support columns are removed by retreating miners and the chambers are destroyed and filled, resulting in more ore being mined.
Also, other methods of subsurface extraction are:
The extraction of hard rocks includes the extraction of hard rocks (sedimentary, metamorphic or sedimentary).
Bore hole mining is a digging and filling method.
Long sloped hole mining, underground caving and block caving