This area includes Panzhihua-Xichang area in Sichuan, central Yunnan, eastern Yunnan, western Qianxi and eastern Qiandong, and karst landforms are developed in the area. The geotectonic position belongs to the western edge of the Yangzi Plateau and the northern part of the South China Tectonic Belt. The mineralization conditions in the area are good, the working degree is high, the mineral resources are rich, and the development degree is also high, about 60% of the mining enterprises and 65% of the environmental geological problems of the mines in the southwest area are distributed in the area. The minerals developed include iron, copper, lead and zinc, manganese, aluminum, tin, gold, nickel, phosphorus, coal, rare earths and a large number of non-metallic minerals. The environmental geological problems of mines formed mainly include mercury pollution, arsenic pollution, fluorine pollution, sulfur pollution, phosphorus pollution, and landslides, mudslides, avalanches, mine pit sudden water, occupying and destroying land resources and landscape resources, soil erosion and other environmental geological problems, which are now divided into five blocks.
(I) Environmental geologic hazards of landslides, mudflows, avalanches and ground cracks in mines in the central Yunnan region
This region includes Kunming City, Yuxi City and Chuxiong Prefecture, which is the most economically developed region in Yunnan Province. The district is rich in mineral resources, now mainly mining phosphorus, copper, iron, coal, construction sand and other minerals, more than medium-sized mining enterprises. There are 159 various types of mining geologic disasters in the district, with 371 deaths due to disasters, making it a more serious area for geologic disasters (Table 3-23). The main types of disasters are landslides, mudslides, avalanches and ground cracks. Phosphorus, copper and construction gravel mining in Kunming and copper mining in Yuxi have a large impact on the geological environment. As phosphorus mines are mostly located along the Dianchi Lake, they have a greater impact on the water quality of Dianchi Lake. Fatalities caused by avalanches and landslides triggered by sand dredging and quarrying around the urban area of Kunming are more prominent, such as avalanches at Xishan quarry and landslides at Sunjiaqing quarry, which have caused deaths. The Dongchuan District of Kunming City has a long history of copper mining, which has had a great impact on the geological environment, with frequent occurrence of mudslides, landslides and other geologic disasters, making it one of the most serious geologic disaster areas in Yunnan Province. Yimen Mining Bureau in Yuxi City, due to improper mining and poor natural conditions, mudslides, avalanches, landslides and springs drying up and other mining geohazards have caused serious damage, such as Fengshan Mine and Shishan Mine, where avalanches piled up in the Caiyuan River, filling up the riverbed by 20-40m, causing tens of millions of yuan of economic losses.
Table 3-23 Statistics on the distribution of mining geologic disasters in central Yunnan
(2) Environmental geologic disasters of mine landslides, ground subsidence, ground subsidence, ground cracks, and mine pit sudden water in eastern Yunnan
The region includes Zhaotong City, Qujing City, Wenshan Prefecture, and Honghe Prefecture. Zhaotong City, Qujing City is located in the northern part of the region, the long history of mine development, mining ore types are mainly coal, copper, lead and zinc, is the main coal-producing areas in Yunnan Province. Due to the history of mining without considering the protection of the environment, coupled with local unfavorable geological factors, the geological disasters triggered by coal mining are serious and the damage caused by the problem is prominent. There are 191 various types of mining geologic disasters in the district, and 83 people died due to the disasters (Table 3-24). The main types of disasters are landslides, ground collapse, ground subsidence, ground cracks and mine pit sudden water.
Wenshan and Honghe Prefectures, located in the southern part of the region, are the non-ferrous metal bases of Yunnan Province, mainly tin, with a long history of tin mining, and are the regions in Yunnan Province with the largest number of medium- and large-sized mines and a well-developed mining industry. The mined minerals are mainly tin, in addition to copper, manganese, lead, coal and limestone. The geological disasters and environmental pollution problems generated by the development of mines in the region are very prominent. There are 193 various types of mining geologic disasters in the region, with 674 deaths due to disasters, making it the most serious area for geologic disasters. The main types of disasters are landslides, ground subsidence, cracks and mudslides. 1962 September 26, old new crown mining plant Huogudu tailing pond collapse, the formation of mudslides, resulting in the deaths of 171 people; in 1996 the old Jinshan "5.31" and "6.3" landslides, days, days, days, days, days, days, days, days, days, days, days, days, and days, days, days, days, days, days, days, days, days, days, days, days, days, days, days, days. The "5.31" and "6.3" landslides at Laojinshan in 1996, which caused 372 people to die or go missing within a few days*** (Table 3-24), are the most serious examples of disasters. The area has a large amount of tailings and washing water production, with total annual tailings production of 1505.97×104t and annual washing water production of 3991.45×104t. Historically, there have been incidents of tin mine effluent being discharged into the lake of Yichu, resulting in thousands of people suffering from arsenic poisoning and the collapse of tailings ponds contaminating the groundwater.
Table 3-24 Statistics on Environmental Geological Problems of Mines in Diandong Region
(3) Environmental Geological Problems of Mine Ground Collapse, Earth Fissure, Landslide, Avalanche, Environmental Pollution, Fluoride Poisoning, and Arsenic Poisoning in Qiandong Region
Guizhou Province is roughly bounded by the north-south Qianyu Railway, which divides the province into two parts, namely, Qiandong and Qiandong.
The northern part of the Qianxi region, around Xishui and Liupanshui, is mainly coal-producing, with 2,394 coal mines. The topography of the area is high and steep, the coal beds are generally shallow, the mining method is underground mining, the area of the empty area is large, the coal gangue is piled up, the coal production is high, the annual output of coal 7424×104t. The main mine environmental and geological problems are the formation of the empty area of the ground subsidence, ground subsidence, cracks, landslides and avalanches and other mine geological disasters, as well as the mine pit, water, occupying, destroying the land resources, environmental pollution, and so on. According to incomplete statistics, the annual output of mine wastewater 718,841×104m3, annual emissions of 625,559×104m3, annual treatment volume of 121,971×104m3, annual recycling volume of 35,892×104m3, the comprehensive utilization rate of 4.99%; the annual treatment volume of mine waste residue 12,239×104m3, annual emissions of 9,069×104t, the annual treatment volume of 6534×104t, annual recycling volume 4741×104t, comprehensive utilization rate of 38.37%; energy mines occupy a land area of 28606hm2, of which 17446hm2 is the mining site, 2193.4hm2 is the discharge site (including the gangue occupation), 1084hm2 is occupied by the tailing pond, and the ground subsidence occupies an area of 7882.1hm2; various types of mines have occurred Geological disasters occurred in 432 places, with 239 casualties; the number of mines that damaged the groundwater equalization system and caused water pollution was 285.
Qingzhen, Xingyi, Qinglong, Zhenfeng and Danxiang in the south-central part of Qianxi region are mainly bauxite, gold, lead-zinc and antimony mines, and there are more than 500 various types of mining enterprises, which cause environmental and geological problems of mines, mainly for landslides, mudslides and other geologic disasters, as well as environmental pollution and land resources occupation and destruction. Occupying land area of about 800hm2, the annual discharge of waste slag 430×104t, the annual discharge of wastewater 220×104m3.
(4) Qiandong region mine water resource destruction, environmental pollution, mercury poisoning environmental geological problems
Qiandong region, including Kaiyang, Zunyi, urnan, Danzhai, Tongren, Wanshan, Songtao, and Bucheon etc., with manganese ore, phosphorus ore, mercury ore and There are about 2,000 non-metallic mines of various kinds. The main environmental and geological problems of the mines are mercury pollution, phosphorus pollution, landslides, mudslides, geological disasters and damage to the groundwater balance system, and the occupation and destruction of land resources. According to incomplete statistics, the mines emit 400×104m3 of mine wastewater annually, emit 1245.64×104t of mine slag annually, occupy and destroy 2126.75hm2 of land resources, and 25 various types of mine geologic disasters have occurred, with 28 deaths.
The problem of mercury poisoning is very serious in this district. At present, there are 46 mercury deposits of different scales, about 120 mine sites and 50 mineralized sites. Mercury anomalies are mainly distributed in Wanshan mercury mine, Tongren mercury mine, Bucheon mercury mine, Danzhai mercury mine, etc. The content of mercury in mercury ore is 0.1% to 0.5%. Mercury that causes harm to the environment mainly appears in the form of natural mercury and mercury vapor. For example, in the Sandu-Danzhai and Wanshan-Tongren mercury mine belts, natural mercury anomalies appear in the soil, water, and air, and diseases of mercury poisoning are more prevalent, and the area is a more typical mercury anomaly area in Guizhou Province. After mercury mines are put into development, the mercury content in the environment increases during the extraction, metallurgical process, aggravating mercury pollution, and the morbidity rate often rises dramatically. In the past, insufficient attention was paid to mine environmental protection, and there was no standardized stockpiling and storage of metallurgical slag, which was directly dumped in the valleys without protective facilities. The mercury content in the slag is between 0.2% and 0.3%, which is polluted by surface water and rainwater filtration and washing. Especially during the flood season, the waste slag flows into the river and farmland with the flood water, polluting the river water and farmland. In the process of mercury refining by fire method, mercury-containing waste gas is discharged into the atmosphere to varying degrees, which leads to the increase of mercury content in the atmosphere. In addition, the metallic mercury spilled on the ground volatilizes and discharges mercury-containing gases to varying degrees, and these gases are inhaled through the mouth, respiratory tract and skin of the human body, causing harm to the human body, and the concentration of mercury in some mercury production workshops has reached 0.65mg/m3, which is 64 times of the permissible concentration in the national health standard.
Some years ago, the relevant units of mercury mine production units and nearby residents to conduct a survey, the sampling rate of 20%, the results of the number of people suffering from mild mercury poisoning accounted for about 10%, moderate mercury poisoning accounted for 1% to mercury processing and smelting of mercury workers most of the proportion of the number of people surveyed, respectively, accounted for 32% and 50%. It can be seen that in the mercury anomaly area, mercury pollution has different degrees of harm to the people living in the area.
(V) Environmental and Geological Problems of Landslides and Mudslides in Mines in Panzhihua-Xichang Area, Sichuan
Panzhihua-Xichang Area, Sichuan is an important mining area, with the famous Panzhihua vanadium-titanium magnetite mine, the Haili Tianbaoshan lead-zinc mine, the Huidong Daliandi lead-zinc mine, the Coronation yak-niu-ping rare-earth mine, and the Haili Lara copper mine, as well as scattered small and medium-sized mines. The mining method of large-scale mines is mainly open-pit mining. The main problems of the environmental geology of the mines are landslides, mudslides, geological disasters of ground subsidence, and groundwater evacuation, environmental pollution, and occupation and destruction of land resources. According to preliminary statistics, the annual output of wastewater in the area is 11,960×104m3, the cumulative amount of slag piled up is 39,089.3×104t, and the area of land occupied and destroyed is 3,528.2hm2. There are slope instability in the quarry and discharge site of Taihe vanadium and titanium magnetite mine, and there is a hidden danger of mudslides in tailing ponds; the discharge site of Lugu iron ore mine has been destroyed, and a large amount of abandoned slag is piled up in the salt well gully, which is a hidden danger of outbreaks of mudslides; Panzhihua Baoding coal mine, the mining area caused a large area of subsidence, cracking, seriously damaged the ecological environment, coal gangue piled up in the gully and mountain slopes, triggering landslides, mudslides geologic disasters and environmental pollution; Panzhihua vanadium and titanium magnetite mine, mining slag piled up into man-made mountains, flood season formation of mudslides, landslides geologic disasters, tailings ponds cover an area of 8km2, the surface water, groundwater are contaminated; Haili, Huidong area Star-dotted copper-lead-zinc mines, quarries formed many times landslides, slag heaps have mudflow potential, groundwater evacuation, surface subsidence, environmental pollution. The lead-zinc deposits in the district, in particular, contain high levels of cadmium, which pollutes water, soil and the biological chain.