The hazards of abandoned mines

Mineral resources are an important force to promote economic development and the basic resources of the industrial chain of the national economy. With the continuous improvement of the society, the continuous improvement of domestic production level, the increasing demand for mineral resources, the mining intensity and scope in various regions are also expanding. Since most mines are open pit mining, it is easy to cause soil damage and wreak havoc on the ecosystem near the mining area. In addition, in the process of mining mineral resources, it will also cause the abuse of a large area of land, seriously affect the natural ecology and landscape of the mining area, and have a very adverse impact on the sustainable development of the mine. At present, a large number of abandoned lands in our country have suffered different degrees of destruction. According to relevant data, before redevelopment, more than 90% of abandoned land was forest and grassland. The restoration of abandoned land and ecological restoration are the most effective measures for mine restoration, which plays an important role in improving the living conditions of the residents near the mine.

The main reason for the abandonment of mine land is that it has been unable to be used as cultivated land under the action of long-term slag and mine pollutants. Under the influence of long-term pollutants, mines also lose nutrients suitable for crops or other plant growth, that is, they lose the basic conditions required for arable land. Therefore, it is necessary to carry out reasonable and effective reconstruction of abandoned mining land, otherwise it will lead to a series of problems, such as soil erosion, sandstorms and so on. In addition, if the abandoned land of the mine is not scientifically rebuilt, it is easy to cause other problems. For example, water pollution, water resources reduction, mining waste pollution of the environment, etc., these serious consequences will directly affect the local economic development and people's living standards.

China is a large country with mineral resources and has a long history of mining development. Mine development has played an important role in promoting the whole process of social and economic development and infrastructure construction. However, with the continuous economic transformation, the development mode relying on mineral resources has been gradually eliminated, and the number of exhausted mines has increased significantly, bringing a series of hazards and problems to the environment, ecology and landscape. Many abandoned mines have become a "scar" exposed to the society, making the ecosystem more fragile, biodiversity reduced, and ecological reverse succession serious.

As an important resource in our country, the mining degree of mineral resources is getting higher and higher. When the mineral resources are highly exploited, the ecological environment of the mine is seriously damaged, and the damage to the ecological environment is inevitable in the mining.

A few days ago, the Ministry of Natural Resources issued a policy to require comprehensive remediation of the ecological environment damage caused by abandoned open-pit mines (including mining sites) along the main stream of the Yangtze River and its main tributaries. By the end of 2020, we will complete the treatment of abandoned open-pit mines within 10 kilometers of each bank of the main stream of the Yangtze River and its main tributaries.

China is a country rich in mineral resources and has a long history of mining development. Mining development has played an important role in promoting the overall socio-economic development and infrastructure construction. However, with the constant change of the economy, the exploitation of mineral resources is gradually being eliminated. The number of depleted mines has increased dramatically, bringing a range of hazards and problems to the environment, ecology and landscape. Many abandoned mines have become a "scar" on society, making ecosystems more fragile and biodiversity reduced.

As an important resource of China, mineral resources are being exploited more and more. In the case of highly exploited mineral resources, the ecological environment of the mine is seriously damaged. This kind of damage to the ecological environment is inevitable in mining.

Environmental hazards of mining production: soil erosion, ground subsidence caused by mines, destruction of biodiversity, and pollution of groundwater by wastewater containing chemicals in the mining process.

I. Water pollution

Mainly due to mining and mineral processing activities, the surface water or groundwater contains acid, heavy metals and toxic elements, and this polluted mine water is called mine sewage. Mine sewage endangers the river and soil around the mining area, and even destroys the whole water system, affecting the domestic water, industrial and agricultural water. When toxic elements and heavy metals invade the food chain, they pose a potential threat to human beings.

2. Air pollution

Dust produced in the process of drilling, blasting and loading and transportation of ore and waste rock at the surface of open pit mining and underground mining, oxidation of waste rock (especially coal gangue) and natural release of a large number of harmful gases, fine matter and dust formed by waste rock weathering, as well as tailings weathering, etc., will produce dust storms in dry climate and strong winds. All these will cause air pollution in the regional environment.

3. Solid waste pollution

In the open pit mine near the scenic spot, due to the damage of mining to the ground landscape, the tourism environment is extremely uncoordinated, and many mines dump solid waste at will, resulting in gullies and rivers silting, poor flood discharge, and constant flooding

4. Land destruction, restoration and soil pollution

Mining, especially open-pit mining, has resulted in the destruction or occupation of large areas of land. According to statistics, there are about 15,000 open pit mines in the United States, destroying more than 30,000 hectares of land every year. In the Federal Republic of Germany, lignite mining alone covers an area of about 21,000 hectares per year. The total amount of land destroyed by mines in China has not yet been detailed national statistics, according to the preliminary information, there are more than 1000 major types of open pit mines, most of which belong to small open pit mines, and the damage to the land is very considerable.

5. Geological disasters

Ground and slope excavation affect the stability of the mountain, and lead to rock (soil) deformation inducing collapse and landslide and other geological disasters. The waste rock (slag) discharged from the mine is often deposited on the hillside or gully, and it is easy to cause debris flow when the rainstorm occurs.

Because the abandoned mining land has many bad physical and chemical properties, especially the heavy metal content is too high, and the pollution process of toxic heavy metals in the soil system is hidden, long-term and irreversible, so it often causes a great impact on the ecological environment of the surrounding area. Such as: destruction of land resources, resulting in the deterioration of the ecological environment; Destroy water balance and aggravate water resources crisis in mining area; Pollute the environment and endanger human health; Destroy the ecological balance of biological community and biodiversity.

Because the mining wasteland has many undesirable physical and chemical properties, especially the high content of heavy metals, the pollution process of toxic heavy metals in the soil system is hidden, long-term and irreversible, so it often has a significant impact on the soil system. The ecological environment of the surrounding area. The influence. Such as: destruction of land resources, resulting in the deterioration of the ecological environment; Destroy water balance and increase water resources crisis in mining area; Pollute the environment and endanger human health; Destroy the ecological balance and biodiversity of the community.