Discussion on environmental geological problems caused by open pit mining and prevention measures

2 Main factors leading to environmental geological problems in mines

Mine environmental problems are the result of human mining activities on geological environment, and are generally affected by natural geographical conditions, mining science and technology level and economic and social factors.

2.1 Physical and geographical conditions

(1) Climate factors Precipitation is the most closely related to environmental geological problems among climate factors. Both the size and intensity of rainfall affect the formation of geological disasters. The annual rainfall in East China is relatively large, and there are often heavy rains in midsummer, which is prone to floods and causes various geological disasters. (2) Topographic and geomorphic factors Topographic and geomorphic factors often determine the distribution of geological hazards regionally. For example, Anhui Lianghuai coal mine, Xuzhou coal mine in Jiangsu province, due to underground mining in the plain area, ground collapse disasters often occur. In the mountainous areas of Jiangxi, southern Anhui and Fujian, gullies are developed. Under the action of precipitation and surface runoff, mining has a strong effect on the original topography and geomorphology, and the slag waste piled up on the hillside is prone to collapse, landslide, debris flow and soil erosion.

2.2 Geological structural factors

The geological structure is complex and the deep faults are relatively developed, especially the east-west and NEE faults are closely related to magmatic activity and mineralization. The mining is also greatly affected by the structure, and the geological disasters such as collapse, landslide and water inrush often occur along the structure zone, resulting in great losses.

2.3 Mining method

(1) Mining methods and methods Different mining methods and mining methods lead to different mining environmental geological problems. The main geological disasters caused by open-pit mining are landslide, collapse, debris flow and so on, which cause damage to land resources, vegetation resources, geological landscape and air pollution. Underground mining mainly causes underground and surface geological disasters such as water inrush in mine and ground collapse in goaf. (2) The level of mining technology The level of mining technology is also a major factor causing mining environmental problems. According to the survey statistics, many modern large and medium-sized mines, due to careful development planning, reasonable mining programs, with their strong technical force and sufficient funds, can prevent and reduce the occurrence of mine environmental problems, reduce the hazards of geological disasters. Some small mines due to the small scale of enterprises, outdated production equipment, backward mining technology, coupled with quick success and short-term behavior, often aggravate the deterioration of the mine ecological environment, resulting in many casualties.

2.4 Economic and social conditions

(1) Economic factors, driven by economic interests, lead to overdevelopment of mining and damage to the mine ecological environment. In recent years, some provinces and cities have tried out the deposit system of mine environmental restoration, which has solved part of the cost of mine environmental treatment to a certain extent. But on the whole, there are still many problems in the capital investment of mine environmental governance in East China. Most small and medium-sized mines are restricted by capital, and their environmental protection work is poor. (2) Environmental awareness On the whole, the public's environmental awareness continues to improve. However, in mining enterprises and even many grassroots government officials, the awareness of "heavy development, light environmental protection" is quite serious, and the drawbacks of "first destruction, after governance" frequently occur. Many mining enterprises, especially some collective and individual mining enterprises, only pay attention to economic benefits, ignore the protection and restoration of the mine ecological environment, coupled with poor supervision by the local government, so that the mine environment is difficult to fundamentally improve. (3) System construction Mine environmental system includes national laws, regulations, regulations and policy rules as well as the relevant administrative provisions of the provinces.

At present, although the construction of the system has been increased, there are still many places to improve and strengthen. From the perspective of provincial administrative regulations, there is still a lack of supporting public policies on mine environmental management, and there is no good combination of exploration rights, mining rights and mine environmental management. It is urgent to strengthen the construction of mine environmental system from the two aspects of policy formulation and implementation.

3 Major environmental geological problems

3.1 Land resource occupation and soil erosion

In the process of open-pit mining, the excavation loss of land and the stripping of surface vegetation are more serious, resulting in the decrease of soil fertility of the topsoil layer, causing soil erosion, and causing the most direct and serious ecological damage. From the perspective of corrosion resistance factors, all the processes of clearing and occupying surface vegetation have seriously damaged the original surface vegetation, increased the degree of looseness of the surface, and reduced the corrosion resistance of the surface. If not paid attention to, it will further aggravate the degree of soil erosion and worsen the environmental quality of the mining area.