As various countries pay more and more attention to the development of environmental protection enterprises, and the intensity of environmental supervision has been continuously increased, “green mine construction” has become a new standard in the mining industry. Various countries are consolidating batches and shutting down batches to curb “small, scattered and chaotic” mining enterprises, eliminating enterprises that fail to meet environmental protection and quality standards and poor safety conditions, and at the same time create a number of green mines.
Mining is mainly faced with the following five environmental problems, and they are also the “big enemies” of green mine construction:
1.Land resource destruction
The destruction of land resources by open-pit mining is mainly concentrated in the construction of mining industrial squares, rock dumping, mountain road repair, ground subsidence and mine stripping. The total number of mines in China has reached 5.86 million hm², destroying forests of 1.06 million hm²and grasslands of 263,000 hm²
The excavation of the ground and slope affect the stability of the mountain and slope, resulting in the deformation of the rock mass, geological disasters such as collapse and landslide. The waste rocks discharged from the mine often accumulating on hillsides or valleys, and they are highly prone to mudslides induced by heavy rain.
3.Solid waste pollution
In the processing of ore, a large amount of solid waste is generated. These “solid wastes” mainly include tailings, waste rock, coal gangue and fly ash. Many mines dump solids and discharges at will, resulting in gullies, river siltation, poor flood discharge, and frequent flooding.
For example, the accumulated stock of tailings and waste rock in China is about 60 billion tons, including 14.6 billion tons of tailings and 43.8 billion tons of waste rock. In the past five years, the annual emissions of China’s tailings have reached more than 1.5 billion tons, of which non-metallic mines produce 30 million tons of tailings annually.
4.The damaged water environment system
Open-pit mine waste rock and tailings are exposed to the atmosphere, and the sulfides are oxidized to make precipitation become acid rain. In addition, the non-standard discharge of the smelting wastewater often causes pollution of surface water bodies near the mining area, these pose serious difficulties for the irrigation of farmland and drinking water for humans and animals (ecological water )use.