Mining is the extraction (removal) of minerals and metals from the earth. Manganese, tantalum, cassiterite, copper, tin, nickel, bauxite (aluminum ore), iron ore, gold, silver and diamonds are just some examples of mining. Mining is a profitable business. Not only do mining companies prosper, but the government also makes money from revenue. Workers can also receive income and benefits.
Mining is usually very destructive to the environment. This is one of the main reasons for deforestation. Trees and vegetation are cleared and burned for mining. Because the ground is completely bare, large-scale mining operations use huge bulldozers and excavators to extract metals and minerals from the soil. To combine (aggregate) extracts, they use chemicals such as cyanide, mercury or methylmercury. These chemicals pass through tailings (pipelines) and are often discharged into rivers, streams, bays and oceans. This kind of pollution pollutes all organisms in the water body, and finally pollutes people who take fish as the main protein source and economic livelihood.
Small scale mining is equally destructive to the environment, or even more. Groups of 5-6 people move from one mining site to another in search of precious metals, usually gold.
Land dredging involves miners using generators to dig a large hole in the ground. They used high-pressure hoses to expose layers of gold bearing sand and clay. The gold bearing slurry is pumped into a sluice box that collects gold particles, while the tailings flow into abandoned mines or adjacent forests. When the mine is filled with water from tailings, they become dead pools. These pools create hotbeds for mosquitoes and other aquatic insects. As long as there are open pools nearby, malaria and other water-borne diseases will increase significantly.
River dredging involves moving along the river on a platform or ship. The miners used hydraulic suction hoses to pump gravel and mud as they moved along the river. Gravel, soil and rock pass through the tailings (pipes), and any gold fragments are collected on the felt mat. The remaining gravel, mud and rock will return to the river, but the location is different from the location of the initial suction. This brings problems to the river. Displaced gravel and mud disturb the natural flow of the river. Fish and other creatures often die, and fishermen can no longer navigate blocked rivers.
Empty field method. Usually, the ore block is divided into room and pillar for two-step mining. This kind of mining method is in an open state with the advance of the mining face and there is no filler in the goaf. The ground pressure control and support of the goaf rely on the temporary ore pillar or permanent ore pillar, or on the stability of the surrounding rock itself. Obviously, this kind of mining method is generally only suitable for mining ore bodies with stable ore and rock. Even if shrinkage mining is adopted in the ore room, because shrinkage cannot be used as the main means to support the open field, it still needs to be supported by the stability of the ore and rock itself. Therefore, the stability of manganese ore and surrounding rock is the basic condition.
Caving method. This method is different from other methods in that ore blocks are mined in one step. With the advance of mining face from top to bottom, the goaf is treated by caving surrounding rock. After the collapse of surrounding rock, it is bound to cause surface collapse in a certain range. Therefore, the basic condition for using this kind of method is that the surrounding rock can collapse and the surface is allowed to collapse.
Filling method. In this method, the ore block is generally divided into room and pillar for two-step mining; Ore blocks can also be mined continuously without room and column. When manganese ore is stable in nature, it can be used for upward mining, and those with poor stability can be used for downward mining. During the mining process, the hollow area shall be filled with filler in time as the main means of ground pressure management (when two-step mining is used, the pillar in the second step shall be supported by the filling body of the ore room). Therefore, the stability or instability of ore and rock can be used as the basic condition for adopting this kind of method.
It is worth pointing out that with the in-depth study of mining methods, combined mining methods across categories have been applied in real production. For example, sublevel caving combined mining method combining open stope method and caving method, sublevel open stope caving combined mining method, sublevel open stope filling combined mining method combining open stope method and filling method, etc. These combined mining methods are not perfect in classification. Using these combination methods, we can absorb the advantages of each method, abandon the disadvantages of each method, develop the advantages and avoid the disadvantages, and expand the application conditions. This trend of combined mining method is conducive to the development of more and more novel mining methods.
In addition, when adopting the two-step mining method, the pillar mining method in the second step should be comprehensively considered with the mining method in the front step room. The second step of pillar recovery is limited by the conditions of the pillar itself, as well as the goaf state and mining interval after the exit of adjacent ore rooms, which makes the pillar recovery work more complex, but the basic methods of mining are still no more than the above three categories.
Mining machinery and equipment is a kind of machinery that processes ores and makes low-quality ores valuable. Separate valuable minerals from gangue. In a narrow sense, it is a machine directly used in mineral mining and rich beneficiation. Including mining machinery and gears (teeth). Broadly speaking, exploration machinery also belongs to mining machinery.
Mining machinery industry is one of the important basic industries that provide equipment for the mining and processing of solid raw materials, materials and fuels. It serves important basic industrial departments such as black and non-ferrous metallurgy, coal, building materials, chemical industry and nuclear industry. Its products are also widely used in the capital construction of basic departments such as transportation, railway, construction, water and hydropower.
There are many professional mechanical equipment used in mining operation, which can be roughly divided into mining equipment, beneficiation equipment and prospecting equipment. Mining machinery refers to the machinery directly used for mineral mining and rich beneficiation, including mining machinery and beneficiation machinery. The working principle and structure of exploration machinery are mostly the same or similar to mining machinery. In a broad sense, it is also a kind of mining machinery. A large number of cranes, conveyors, ventilators and drainage machinery are also used in mine operation.