How do foreign countries do in mine ecological environment governance?

In the process of mining, a large amount of land has become abandoned land due to the loss of utilization value, such as open-pit stope, waste rock yard, tailings reservoir, subsidence area, etc. Mine restoration is to repair the pollution of abandoned mining land and realize the reuse of land resources. Under natural conditions, it takes about 100 years for the abandoned mining land to recover its habitat through natural succession. Therefore, it is particularly necessary to restore the ecological environment of mine wasteland through manual intervention. It can be said that mine ecological restoration is not only one of the important steps to alleviate soil loss and desertification, but also one of the important means to explore its value through mine ecological restoration, transformation and utilization.

At present, with the attention of countries all over the world to the ecological environment, many countries have paid attention to the restoration of mines and increased the ecological construction of mining areas. It is understood that there are many successful cases for mine transformation at home and abroad, and there are mainly seven types: ecological restoration class, natural resources utilization class, tourism development class, reclamation class, water diversion class, waste treatment plant class, storage class. Among them, ecological restoration and tourism development occupy more than half of the mine restoration cases, and have high restoration value. In practice, the transformation of abandoned quarry is mainly to add humanistic landscape elements on the basis of its own land resources and unique natural landscape, and transform it into wetland park, ecological park, urban park and other tourist attractions while restoring ecology.

(I)At the beginning of the last century, the Western developed countries began the related work of ecological restoration of quarry. Britain, the United States, Australia and other developed countries have a long history of mining, and the initial research on restoration ecology mainly focused on the restoration of abandoned land vegetation left after mining. In 1971, the reclamation rate of mine land in the United States was 79.5%. The concept of land reclamation in the United States mainly emphasizes the ability to restore to the state before destruction, requiring the restoration of farmland and forests, and the control of water erosion and toxic sediment. Ensure that the land surface remains unchanged and the water table remains at its original level; Keep the topsoil in its original position; Pay attention to the prevention and control of harmful and acidic substances; Prevent landslides and other disasters caused by deposits. Since 1940, Germany has paid great attention to minimizing the destruction of the ecological environment in the mining process, and the reclamation after mining is not only planting trees or land preparation, but also considering the ecological changes and residents' environmental requirements from a macro perspective. Because of its dense population and developed industry, France first prevents pollution and restores ecological balance without changing the area of agriculture and forestry. France attaches great importance to planting grass in open waste dumps and promoting the activation of soil, which becomes new farmland after certain reclamation. The Australian government attaches great importance to the restoration of abandoned mining areas, and strictly manages the ecological environment of production mining areas, adheres to the road of sustainable ecological mining, implements multi-professional joint investment, and introduces many new computer technologies, and now has reclamation as part of the mining process. In countries such as the United States and Australia, the modern 3S technology and other new technologies and new concepts currently quoted have been widely used in ecological restoration. The goal of ecological restoration is not only to plant trees and grass, but to establish a complete ecological service system that can maintain itself and run well.

The United Kingdom and the United States produced the earliest engineering greening technology, in the early 1940s, some European and American countries to prevent slope rain erosion invented plant POTS, hydraulic spray seeding technology; The United Kingdom invented plant seed spray and spray emulsion asphalt technology, and Japan developed a more practical spray greening technology after several tests in 1958. In 1973, Japan developed a fiber soil greening method by mixing fiber, sandy soil and mud, and spraying in a step pattern. After 1960, some developed countries began to develop slope greening technology, combining engineering and vegetation, such as horizontal grid, planting bag greening and guest soil planting technology, and finally developed into spray mixed planting technology.

(2)The research on ecological restoration of abandoned mines in China started late. In the 60's of last century, our country began the practice of mining reclamation, mostly on the waste rock yard or closed tailings pond on the simple formation and afforestation. Due to the poor ecological environment, toxic matrix, lack of soil and other factors, the reclamation rate of mine abandoned land is still at a low level. With the gradual advancement of mining reclamation work in China, the research on ecological restoration technology of mining abandoned land has also been widely concerned, and has initially formed a certain scale after the 1990s of last century. In recent years, with the enhancement of China's economic strength and the enhancement of ecological environmental protection awareness, people pay more and more attention to the ecological restoration and transformation of abandoned mines. The research field mainly focuses on the abandoned land of coal mines and the vegetation cover of non-ferrous metal tailings ponds. At present, the domestic research on mining abandoned land is mainly combined with land development and land consolidation, and according to the actual situation, the abandoned mine development is transformed into industrial land, cultivated land, tourism landscape and tourism land, storage land, breeding land, military land or green land.

Because of the difference of mineral resources, the treatment key of abandoned mines is also different. The environmental problems of coal mine wasteland are goaf area, subsidence area, coal gangue pile, etc. The key of its treatment is the treatment of goaf area and coal gangue pile. Non-ferrous metal mines such as copper, lead and zinc mines, in addition to the treatment of the pit, but also chemical treatment of waste slag heap, waste slag heap and other pollution of the nearby soil and groundwater through the rain action; The abandoned quarry is mainly used for the prevention and control of geological disasters such as landslide and debris flow and the restoration of vegetation.

As a kind of abandoned mining land, the restoration and treatment process of abandoned quarry should be as follows: investigation of the status quo of abandoned quarry → overall planning of restoration and treatment → geological disaster prevention → treatment of unstable slope, waste gas pit, mine pit, etc. → vegetation restoration.

Nowadays, the ecological restoration work of mine is being carried out orderly and extensively in various places of our country. While achieving good results, China is also actively exploring new mine restoration models, drawing on representative restoration projects at home and abroad, so that the mine restoration project is transformed from simple and pure vegetation restoration to emerging industries. According to the planning and construction of the city, in the suburban edge of the city, the appropriate selection of abandoned mining land and the construction of mining site park, ecological demonstration park, amusement park and other types of landscape can not only make the abandoned mining land can be reused, but also add a beautiful landscape line for the construction of the city, giving the city more cultural connotation.

(3)In the process of ecological restoration of abandoned land in metal mines, phytoremediation is considered to be the most promising technology. Substrate improvement technology is a prerequisite for phytoremediation, which fundamentally changes the limiting factors of plant growth, and microbial remediation technology can improve plant remediation.

At present, the research on ecological restoration technology of abandoned land of metal mines is mostly carried out in greenhouse pot and small-scale experimental sites. Due to the great differences in abandoned land of different regions and different types of metal mines, the application of these technologies in field restoration often fails to achieve the expected results due to changes in environmental factors and site conditions. Therefore, it is necessary to carry out the research on the ecological restoration benefit evaluation system of abandoned mining land, so as to provide support for the reasonable selection of ecological restoration technology.

The main ecological restoration technologies of abandoned land in metal mines are: first, matrix improvement technology. Substrate improvement is a prerequisite for ecological restoration. Physical improvement mainly includes topsoil backfill, guest soil method and so on. Chemical improvement is used to repair most abandoned land in metal mines. For alkaline abandoned land, ferrous sulfate, bicarbonate and gypsum should be used for improvement. The second is phytoremediation technology. Phytoremediation is the most promising technology in the ecological restoration of mine wasteland. Through the establishment of suitable and stable plant communities on abandoned land, it can not only effectively control all kinds of pollution in abandoned land and improve the damaged ecological environment, but also use the renewal and promotion of vegetation restoration to gradually restore the function of land, improve and beautify the landscape, increase biodiversity, and finally make the ecosystem enter a virtuous cycle. Phytoremediation technology includes plant extraction technology and plant stabilization technology. The third is microbial repair technology. Microbial restoration technology is a kind of technology for ecological restoration of abandoned land by inoculating plants with mycorrhiza and utilizing rhizosphere microbial activities to improve soil microenvironment, improve plant nutrition and promote plant growth and development. The fourth is the auxiliary repair technology. According to the characteristics of mine abandoned land, in addition to taking the necessary ecological restoration technology, it is also necessary to assist some measures such as slope stability and drainage, so as to achieve the best effect of ecological restoration. -

Typical mine ecological environment restoration at home and abroad

At present, there are many successful cases for mine transformation at home and abroad, which have different functions and characteristics. Because of the early start of urban infrastructure construction in foreign countries, the ecological environment problems of quarry occurred earlier and more serious, so the research and practice of ecological restoration of quarry are more in-depth. In recent years, the practice of research and exploration on the restoration and management of abandoned quarry has been emerging.

1. Japan's state-run Akashi Kaikai Park

Japan's state-run Akashi Kaikai Park used to be a large quarry with exposed mountains covering about 140 square kilometers. Beginning in the 1980s, Hyogo Prefecture, where the island is located, commissioned renowned designer Tadao Ando to plan and design, and set up a committee of greening experts to carry out vegetation restoration. Its planning emphasizes the restoration of the natural state, the formation of a good landscape and the creation of a recreational space for people, and its theme is "make the park get the return of life". The overall goal, first and foremost, is to heal the scars left by decades of mining, including a network of three-dimensional metal plates fixed to the bedrock in a honeycomb shape, filled with fresh soil and covered with grass curtains to conserve water. At the same time, the park will also become the service infrastructure of the region, including the international conference center, star-rated hotels, large greenhouses, open-air theaters and other facilities to create a future-oriented leisure place.

2. Ecological restoration of Biville quarry in France

Biville Quarry in France has the characteristics of large scale, large elevation difference and serious ecological degradation. In the renovation, the industrial traces of the site are retained and transformed into a distinctive and iconic place in the new landscape structure, which reflects the respect for the historical context of the site.

The Biville quarry is a linear crack of 450 m long and uniform width, with a barren and uneven slope of 45 degrees, with a drop of 20 to 40 m. The designers built it into a recreation area with a 3.5 square kilometer lake. The idea is not to hide the traces left by the stone mining process, but to preserve them as site features, simply to ensure the continuity of the best locations for the natural restoration of the ecosystem, and then to introduce some vegetation to restore the abandoned quarry to a natural state. The renovation includes the design of a series of facilities and equipment to direct the flow of water to the valley floor to form a lake.

3. Shanghai Tianma Mountain Shimao Deep Pit Hotel

As the world's first hotel built in the waste stone pit, Shimao Deep pit Hotel located in Shanghai Sheshan is undoubtedly a strange project, the construction method, building structure and traditional building requirements are very different, after completion or become the world's lowest altitude hotel, known as the world architectural miracle. Located at the foot of Sheshan Mountain in Shanghai's Songjiang National Scenic Area, the "Deep Pit Hotel" is an abandoned pit with a depth of 80 meters. The deep pit was originally a quarry, and after decades of mining, it has formed a deep pit with a circumference of kilometers and a depth of 100 meters. Shimao Group made full use of the natural environment of the deep pit, and built a five-star hotel with great imagination. The whole hotel and the deep pit are integrated and complement each other, which is a miracle in the history of human architecture, and also a masterpiece of nature, humanity and history.

4. Yellowstone National Mine Park

Huangshi National Mining Park is located in the Tieshan District of Huangshi City, Hubei Province. The core landscape of Huangshi National Mining Park is the "Mining and Metallurgical Grand Canyon", which is shaped like a huge inverted gourd. It is 2200 meters long from east to west, 550 meters wide from north to south, with a maximum drop of 444 meters and an opening area of 1.08 million square meters.

The east open pit of Daye Iron Mine has formed the world's first high and steep slope. In order to control the ecological environment, the mine has invested tens of millions of yuan to form the largest hard rock reclamation base in Asia. In the design of Huangshi National Mining Park, the natural ecology and human ecology of the mine are restored through the landscape design method of ecological restoration. The "ten highlights" of the mining area are "seamlessly connected" with the construction of the park, and the focus of the development and construction of the park is to carry forward the mining culture, reappear the mining civilization, show the humanistic characteristics, improve the mine grade, open a new road to tourism, positioning it as "popular science education base, scientific research and teaching base, cultural display base, environmental protection demonstration base"; It fully demonstrates the Chinese mining culture with a long history of thousands of years, and provides people with a place that integrates tourism, scientific activity investigation and research, realizing the theme of harmonious coexistence and common development between man and nature.

5. The Garden of Eden

The Garden of Eden is located in Cornwall, England. The site was originally a huge pit left by local people digging clay. The Garden of Eden in England is the largest single greenhouse in the world, containing almost all the plants on the planet.

In the greenhouse with the structure of the giant space grid, a natural biological community is formed. Eden is built around the plant culture, the integration of high-tech means of construction, with the theme of "people and plants symbiosis and integration", with "plants are indispensable friends of human beings" as the construction concept, with high scientific research, industry and tourism value of plant landscape theme park. Eden itself is a model of energy conservation and environmental protection, realizing the restoration of a natural ecological area in an area that has been polluted and destroyed by industry. -

Ecological restoration of Shouyun Iron mine in Beijing

Basic situation

Located in Jugezhuang Town, Miyun County, Beijing, the project covers an area of 2.5 square kilometers and is divided into six areas, including mining area, dump, tailings reservoir, industrial site, transportation line and living area, among which a large number of exposed slopes are formed in the mining area, dump and tailings reservoir.

Existing problem

1. The high slope of the mining area is steep, seriously weathered, there are pumice stones, and the stability is very poor.

2. Tailings tailings on the slope of tailings pond have high heavy metal content, loose texture and no soil conditions for plant growth.

3. The soil of the dump is poor, and the water and fertilizer retention capacity is poor.

Major technology

1.VRT base plate plastic vegetation restoration technology. It includes planting substrate spraying technology, ecological vegetation blanket technology, ecological vegetation bag technology, ecological grouting technology, vertical rock surface planting trough vegetation restoration technology and soil improvement technology.

2. Ecological alignment allocation technology. Considering plant diversity, seasonality, and native nature, irrigation, grass, flowers, and climbing are combined to create different seasonal landscapes and realize ecological governance close to nature.

Construction technology

1. Ecological restoration in the mining area: vertical slope adopts vegetation restoration technology of planting groove, fissure slope adopts planting substrate spraying and planting seedling greening restoration technology, and slope slope with slope slope greater than 60 degrees adopts anchor fixing, hanging grid net, planting substrate spraying and laying ecological vegetation blanket technology, and slope platform adopts seedling planting and platform blocking technology.

2. Ecological restoration of tailings pond: adopting pavement finishing, soil improvement and laying ecological vegetation blanket technologies.

3. Ecological restoration of the waste dump: the use of planting substrate spraying, ecological grouting technology, to create a plant growth base plate technology.

Repair effect

The control rate of disturbed land in mining area is above 95%, the total control degree of soil and water loss is above 94%, the soil loss control ratio is between 0.4 and 1.3, the slag control rate is above 98%, and the forest and grass vegetation restoration rate is above 98%. At the same time, the forest and grass coverage rate reached more than 31%.