Due to the immovability of mineral deposits, serious environmental pollution occurred during the long-term mining and operation of the mine, which not only destroyed the regional animal and plant system, but also caused serious damage to the regional water system structure. Based on this, the main points of research are mine environmental governance methods and ecological restoration technologies, and a simple exploration of mine governance.
Mine mining seriously pollutes the environment
In the past ten years of development, my country’s mining development has developed rapidly, and mining operations in the national economy have also risen sharply, achieving outstanding economic benefits. However, my country's large-scale mining has also caused great damage to the country's land environment, prompting a sharp decrease in land resources around the mining area.
● Pictures of mine excavation site
Mining has caused severe damage to the ecological environment. The main effects are as follows:
■①Changes in hydrogeological conditions and regional water pollution. In the process of mining, the occurrence of problems such as drainage, cracks and collapses in the mining area will directly affect the changes in the underground water storage structure of the mining module in the mining area, which will lead to the decrease of groundwater level, the appearance of large-area draining funnels, and changes in surface runoff. The problem occurs. Coupled with the discharge of industrial waste water such as pit water and wastewater leaching water during the mining phase, it has caused serious pollution to the water sources around the mine.
● Crazy destruction of a mining site in a mountainous area in Henan
■②The probability of geological disasters has increased. The progress of mining operations will inevitably lead to underground goaf problems. The occurrence of underground mining problems will not only affect the stability and safety of the surrounding mountains and slopes of the mine, but also increase the probability of accidents such as ground cracks, collapses, and landslides. In addition, a large amount of waste slag discharged from mining is accumulated on mountain slopes and valleys. The mixing of waste rock and slag with soil will directly cause the friction and water permeability of waste rock and slag to decrease. If there is a heavy rain at this time, it will promote the intensification of soil erosion and increase the probability of debris flow.
●Mining activities cause serious soil erosion
■③Soil pollution degradation. After mining, the topsoil needs to be removed and covered with new soil or slag. The heavy load of large mining equipment during the mining process will cause the slag or new soil to gradually harden and compact. Coupled with the occurrence of mining subsidence and the discharge of solid waste residues in the mining area, it will directly cause cracks in the soil. With the expansion of soil fissures, soil nutrients will gradually be lost, and the toxic components in the solid waste residues of mines will directly infiltrate the soil, causing serious acid-base pollution, heavy metal pollution, and organic pollution.
● Qinghai Muli grassland was polluted by mining
Mine pollution control is imminent
Mine environmental management and ecological restoration mainly use man-made engineering methods or measures to create suitable soil environmental conditions for regional vegetation growth at the position of abandoned bare land slopes in mines with poor vegetation restoration. At the same time, pioneer plant communities were introduced to cover the bare ground at an initial stage to avoid desertification and soil erosion in abandoned mines, and lay the foundation for the formation of the later target community.
Main reconstruction types and restoration methods:
Ecological reconstruction of tailings yard:
Tailings as filling material for underground goaf of mine
Covering soil on the tailings dump
Planting crops or planting trees
Sand making from tailings and as building materials
Recovery of mined areas in open pit mining:
Natural vegetation restoration
Artificially promote vegetation restoration
Factors affecting mine restoration:
Soil factors: Soil is a prerequisite for the normal operation of mine environmental management and ecological restoration operations, and is also a key factor for the survival and growth of vegetation on the surface of the lithosphere. It can not only provide the mineral elements and water needed for the survival and growth of vegetation, but also provide a carrier for the mutual operation of biological parts and inorganic environments in the ecosystem. In this case, factors such as soil pH, soil structure, parent material, nutritional status and other factors directly affect the effects of mine environmental management and ecological restoration.
Light intensity: Light intensity is the main energy provider for vegetation photosynthesis in the mining area. According to the difference in light intensity, environmental management personnel in mining areas can choose appropriate types of ecological restoration vegetation, such as shade-tolerant plants and positive plants, to ensure the effect of ecological restoration.
Temperature and moisture: Temperature can affect vegetation growth activity through two channels: air temperature and ground temperature. The growth activity of vegetation directly affects the efficiency of environmental governance and ecological restoration in mining areas; moisture is a key factor for the normal survival and growth of vegetation, and it is also the main element in vegetation photosynthesis and respiration. It can provide a good channel for vegetation mineral nutrient absorption and transportation. The vegetation water supply situation also directly affects the effect of environmental governance and ecological restoration in mining areas.
How to prevent and control mine pollution?
● Mine pollution has caused great harm to the entire ecological environment
Policy:
1. Improve relevant laws and regulations and protect the mine environment in accordance with the law.
2. Carry out environmental surveys in mining areas and build a geological environment information system in mining areas.
3. Speed up the scientific research and transformation of mine environmental treatment technology.
4. Strengthen supervision to prevent and control the deterioration of the mine environment.
Specific implementation measures:
1. Implement cleaner production and develop green mines.
2. Introduce new reconstruction technology and carry out demonstration projects.
3. Establish an ecological deposit system linked to the ecological protection standards for mineral development.
4. It is necessary not only to restore vegetation and soil in the mining area, but also to restore the surrounding terrain and water system pattern.
5. Mining areas with high pollution, serious waste of resources, and poor safety should be closed down as soon as possible.
6. Develop a punishment evaluation plan and corresponding inspection and punishment system for violating the ecological protection and restoration standards of mineral development.
7. Improve the mining license system, stipulating that the mining license application must include an ecological protection and restoration plan that meets the ecological protection and restoration standards for mineral development.
Remediation of soil pollution in mines
Picture of mine pollution scene:
●Mining pollution site of a stone coal mine in Hunan
Land visit and exchange method:
When the soil is only slightly polluted, the method of deep plowing and plowing is used, and the method of removing the soil from another place is used when treating the heavily polluted area, that is, the method of removing the soil or replacing the soil. Retrieving and replacing soil has a very good effect on the restoration of heavy metal pollution in the soil. Its advantages are mature and comprehensive restoration methods. The main disadvantages are large engineering volume, high investment, and easy to cause problems such as soil fertility decline.
Thermal repair method:
Thermal remediation technology involves the use of heat conduction (heating wells and hot walls) or radiation (such as radio wave heating) to repair the soil, including high temperature (about 1,000 °C) in-situ heating repair technology, low temperature (about 100 °C) in-situ Heating repair technology and in-situ electromagnetic wave heating technology, etc.
Chemical curing method:
The main effect of heavy metals on soil is its mobility. The purpose of chemical solidification of heavy metals is to add a solidifying agent to change the physical and chemical properties of the soil, and reduce its mobility through the adsorption or precipitation of heavy metals. After the heavy metals in the soil are fixed, not only can the pollution impact on deep soil and groundwater be reduced, but it is also possible to rebuild vegetation in the soil.
Typical biological restoration techniques:
Bioremediation includes animal and plant restoration. It can be divided into technologies such as plant stabilization, plant volatilization, plant extraction, and soil animal restoration. Using this natural method to transform the form or enrichment of heavy metals can improve soil fertility to a certain extent.
Remediation of contaminated soil in mines follows the main principles
●Clear water and blue sky is our unremitting pursuit
■①The principle of equal emphasis on production and construction and remediation of contaminated soil. In the construction and production process of mining areas, the "three simultaneous" system is conscientiously implemented, clean production technology is promoted, and the comprehensive utilization of "three wastes" is actively carried out to reduce pollutant discharge. Focus on the treatment of mine tailings pond and surrounding land, adopt resolute and powerful measures, apply physics, chemistry, plant and other remediation technologies to make the pollution treatment work solidly promoted.
■②The principle of sustainability. Sustainable development refers to the coordinated development of economy, society, resources and environmental protection. It not only achieves the goal of economic development, but also protects the natural resources and environment on which mankind depends, so that future generations can develop sustainably and live and work in peace.
■③The principle of overall planning, comprehensive management, and local conditions. To carry out governance work, we must make overall planning, multi-pronged and comprehensive governance. Proceed from reality, adjust measures to local conditions, highlight key points, and implement step by step.
To sum up, the future research trend of mine management is not only to improve the processing technology of a single method, but also to use physical, chemical and biological methods in combination to maximize strengths and avoid weaknesses to obtain an optimal treatment effect.
