Study on ecological restoration status and treatment countermeasures of abandoned mines left over from history

2.3 Restoration Mode

The problems of mine ecological environment include landscape type destruction, environmental quality type destruction and biological type destruction. The traditional restoration model mainly focuses on landscape recurrence restoration (eliminating geological hazards and vegetation coverage), and less takes into account environmental quality restoration (controlling water, air and soil pollution) and biological restoration (restoring biological communities and species). At present, the mode of mine environmental treatment and restoration is simple, resulting in the economic and social benefits are not obvious, and the investment and return have not formed a virtuous cycle.

Adhere to the priority of ecological restoration and management, adopt the "development, governance", according to the type of mine and regional location of the ecological environment state index and the degree of damage to the surrounding environment, classified policies, regional control, hierarchical governance, step by step. On the basis of the landscape reproduction model, we should expand a variety of potential restoration models, and transition from land reclamation to a diversified development trend that takes into account the benefits of all aspects. At present, there are not many examples of mine parks, country parks and creative and cultural industry models in China, and they have not formed a scale and industrial chain, which can become the future direction of operation. Seize the opportunity of the country to vigorously implement the rural revitalization strategy, make full use of various policies to help and benefit agriculture, and repair and manage abandoned mines well while building new rural areas.

2.4 Restoration Works

In recent years, the implementation effect of the mine rehabilitation project has made obvious progress, but there are still problems such as unreasonable restoration plans and goal setting, lack of scientific and normative, low restoration standards for most management projects, low participation in funds, less acceptance standards and norms, and uneven acceptance quality.

Local governments and restoration enterprises should work out different types of mine restoration plans according to factors such as the type of mine pollution, the degree of ecological environmental damage, and human geography, with phased indicators and the completion time of the overall restoration target, and conduct strict review with high standards to avoid loopholes in the plans. Mine restoration funds are strictly managed as a whole, and their use is supervised and inspected by means of "random sampling of inspection objects in the supervision process, random selection of law enforcement inspectors, and timely disclosure of random inspection and investigation results to the public" (referred to as "double random, one public") to ensure that all funds are reasonably used in restoration projects. Revise and improve the acceptance standards of the project, hire qualified and experienced mine restoration related institutions, third-party design institutes and mine management companies to carry out the one-by-one acceptance inspection of the mine treatment plan, medium-term objectives and ecological restoration after treatment, and put forward targeted improvement plans for the problems and deficiencies found in the acceptance, so as to promote rectification through acceptance and avoid inadequate treatment measures. The phenomenon of substandard treatment projects occurs.

2.5 Repair Techniques

Mining has caused serious damage to topography and landform, and there are subsidence areas, tailings ponds and waste discharge fields covering a large area, etc. As of 2018, a total of 1.2×l04 ground collapse disasters have occurred in abandoned mines in China, and the solid waste stock is 4.96×1010t, with high construction technical requirements. Compared with water pollution and air pollution, mine restoration has less attention, less research on related technologies, and the existing technologies are relatively simple, mainly in geological environment management, secondary disaster prevention and control, vegetation restoration and land reclamation. In the "National Soil Pollution Survey Announcement" published in 2014, 1,672 soil points in 70 mining areas accounted for 33.4% of the exceeded points, and the main pollutants were cadmium, arsenic, lead and polycyclic aromatic hydrocarbons. The soil pollution control technology was weak, the plant survival rate was low, and no integrated control system was formed. In recent years, some new technologies have achieved good results, but the cost is high and the application is limited. In 2013, the Technical Code for the Protection and Restoration of the Ecological Environment in Mines (Trial) issued the development of industry standards, which did not enforce and play its due role in guiding technical requirements for the protection and restoration of the ecological environment, including waste dumps, open-pit stopes, tailings ponds, special roads for mining areas, mining industrial sites, subsidence areas, gangue yards, polluted sites, etc. The regulations on pollution prevention and control involving air, water and soil are relatively simple, and there are no more detailed technical guidelines and norms for one aspect, and no new technical norms have been issued since then.