Environmental geological impact assessment and ecological restoration of abandoned mines

1. Various impacts of abandoned mines on the environment

1.1 Destruction of land resources

In the process of mineral resources development, the damage to the land mainly includes: the damage to the land by the mine, the damage to the land by the storage of waste materials, the damage to the land by a series of geological disasters caused by mining, the damage to the road and related mining equipment in the mining area. The loss of cultivated land resources is mainly reflected in the wide range of abandoned cultivated land, and the destruction of cultivated land resources is mainly forest land. The damage of abandoned mines to land resources is also manifested in the high cost, difficulty and long time of restoration.

1.2 Destruction of landform and landscape

In the process of mineral resources development, the damage caused to the surrounding terrain and landscape is mainly manifested in: in order to adapt to the terrain conditions of the open pit, mining road, industrial land and other engineering sites, the construction unit has reformed the original terrain, resulting in a certain degree of damage. At the same time, due to the mining of ore, waste is piled up, and the storage of ore will also bring great pressure to the original terrain, which will have a certain impact on the terrain. For example, the rare earth mining process, the so-called "mountain moving movement", like shaving the head, the top soil and vegetation of the mountain are removed, the surface cultivated soil is excavated, and the bedrock is directly exposed, which causes damage to the mountain vegetation that is difficult to repair.

1.3 Geological disasters in mines

The disasters caused by mining directly or indirectly include collapse, debris flow, cave collapse, landslide, mine water inrush and so on. Landslide, ground collapse and mine water inrush are the most common geological disasters. People should not only suffer from geological disasters caused by improper construction in the mining process, but also suffer from geological disasters caused by improper treatment of slag piles, tailings piles, goaf and other prevention and control measures.

1.4 Aquifer damage

In the process of mining, due to the use of modern mechanical equipment, it will cause serious pollution and damage to the underground water in the mining area, and the loss and imbalance of underground water is the main cause of groundwater loss. Underground aquifers are often connected to underground rivers, and the flow interruption and diversion of underground aquifers will produce devastating blows to underground ecosystems. Due to the insufficient attention and understanding of underground rivers, it is more difficult to damage and repair them, which makes them more ecological and research value.

1.5 Soil and Water pollution

In areas rich in mineral resources, in addition to a large number of ferrous metals, there are also many nonferrous precious metals, which is easy to cause soil and water pollution. Due to the particularity of non-ferrous precious metals, during mining, heavy metal pollution is generally not highly valued, protective measures are not in place, or even no protective measures are taken, which is easy to cause heavy metals and other pollutants to migrate to the surrounding soil and water, causing serious pollution to the surrounding environment.

Rare earth mining environmental problems are particularly serious, rare earth engineering to solve the environmental problems of the initial investment cost is very large, because of this, private development of rare earth often can not meet the environmental requirements. In the suburb of Baotou City, Inner Mongolia Autonomous Region, the rare earth waste slag formed by Baotou Steel rare earth is transported to the tailings dam through the pipeline with the waste liquid, and accumulated over time to form the current capacity of 170 million tons of "rare earth lake", which is seriously polluted. Some parts of Ganzhou have been labeled "unfit for human habitation" because rare earth mining has seriously polluted drinking water and agricultural irrigation water. Rare earth elements are non-essential trace elements for human body, and long-term low dose exposure or intake may have adverse consequences on human health or metabolism in vivo.

2. Comprehensive impact of abandoned mines on the environment

There are three main impacts of abandoned mines on the environment: geology, ecology and environmental pollution. Under complex geological conditions, the existence of landslide and debris flow will lead to the destruction of slope vegetation, and then affect the landform. From the point of view of ecological environment, because forest vegetation and surface vegetation have been damaged to varying degrees, soil erosion has been intensified, which has caused serious impact on the growth and growth environment of animals and plants, which has led to the disappearance of the diversity of plants and animals. In terms of environmental pollution, due to the geological conditions of the mine, it will lead to the increase of water pollution, soil pollution and solid pollution, and long-term infiltration and diffusion will form a wide range of pollution.