Geological structure: Kaiping syncline is a northeast syncline structure in Kailuan coalfield. Its northeast end rises and inclines to the southwest, and its southeast wing inclines about 20 degrees, while its northwest wing is slightly steeper. The axis of syncline is red variegated strata in late Permian, the wing is Permian coal measures in Shiyan and the outer edge is Ordovician limestone. The depth of the Ordovician top surface of the shaft is generally less than 2000 meters. The whole syncline is basically covered by Quaternary, and the overburden thickens from northeast to southwest, reaching more than 800 meters thick at the southwest end of the coalfield. Mesozoic diabase intruded into the coal measures strata in some areas of the southeast wing of syncline, and appeared as dike and vein.
1. Coal seam
① Late Carboniferous Tangshan Formation. It is composed of mudstone and sandstone alternating between land and sea with thin limestone and bauxite, with a thickness of 73 meters and 3-4 thin coal seams. ② Tang Ping Formation in the middle of Late Carboniferous. It consists of thin limestone and coal seams, with alternating sand between land and sea, with a thickness of 65 meters. ③ Zhaogezhuang Formation in the late Late Carboniferous. It consists of continental and coastal sandstone and siltstone sandwiched with coal seams, with a thickness of 79 meters. ④ Damiaozhuang Formation in the early Early Permian. It is composed of continental sandstone, siltstone, mudstone and coal seam with a thickness of 74 meters. The whole coal measure * * * contains coal seams 18, including 5~7 layers of minable and locally minable coal seams, with a total thickness of m. ..
2. Resources
The coal resources in Kailuan coalfield are 10.8Gt, and the proven coal reserves are about 4Gt. There are gas coal and fat coal! It is a kind of coal with low ash content and sulfur content, and it becomes an excellent coking coal after washing. There are many layers of bauxite and clay minerals in coal measures and their overlying strata. Ceramics and refractory products have been developed and processed, and there are still prospects for further development. Coal measures and coal seams
Jixi coalfield
Layered and spherical pyrite also has development prospects.
3. Geological conditions of mining
The coal seams in Kailuan coalfield are mainly medium-thick coal seams, and the dip angle changes from slow to steep, with general geological conditions. Coalfield hydrogeological conditions are complex, with five main aquifers and abundant water, especially the karst fissure water of coal measures under Ordovician limestone, which poses the greatest threat to the mine and has caused water inrush and extraordinarily serious water inrush disasters many times. The mine in the northwest wing of syncline has high gas content, belonging to high gas mine and gas outburst mine; The southeast wing is low, which is generally a low gas mine. The spontaneous combustion period of coal seam is long, and there is generally no spontaneous combustion phenomenon.
4. Overview of development
Kailuan coalfield had coal mining activities in the Ming Dynasty. 1878, Li Hongzhang and Tang organized Kaiping Coal Mine, and the coal was shipped on 188 1 year. After Keelung Coal Mine in Taiwan Province Province, modern coal mining operations began. 1900 Kaiping coal mine was changed to British business, and 1908 Luanzhou coal mine was established. 19 12 Kaiping and Luanzhou coal mines were merged into Kailuan Mining Bureau and operated by British businessmen. 1949 after the establishment of People's Republic of China (PRC), it was taken over by the state. In recent 40 years, Kailuan Mining Bureau has made use of its location and traffic advantages to carry out high-intensity mining. At present, the shallow coal resources in this coalfield have been utilized. There are 9 production mines in the coalfield of Kailuan Mining Bureau, with an annual total production capacity of 20.80MT and an annual coal output of nearly16.00 mt. The original Guogezhuang Mine has been mined, and the remaining coal reserves of Tangjiazhuang Mine are not much, which will be scrapped after mining. Kailuan Mining Bureau has developed and built coal-producing areas such as Chezhoushan and Linnancang in the west of Kailuan coalfield. There are other local coal mines available for coal development in the coalfield, with an annual production capacity of about 1 10,000 tons. Qinshui coalfield is a large Carboniferous-Triassic coalfield with the largest coal production in China at present. Located in the south-central part of Shanxi Province, between Taihang Mountain, Luliang Mountain, Wutai Mountain and Zhongtiao Mountain, it spans more than 20 cities and counties such as Taiyuan, Shouyang, Yangquan, Xiyang, Heshun, Zuo Quan, Wuxiang, Qinxian, Changzhi, Gaoping, Jincheng, Yangcheng, Qinshui, Anze and Qinyuan, covering an area of nearly 30,000 square kilometers. There are large mining bureaus such as Yangquan, Lu 'an and Jincheng in this coalfield, and there are hundreds of local coal mines, with great coal development. It is the largest supply base of anthracite, chemical coal and coking coal in China.
1. Geological structure
Qinshui coalfield is a tectonic basin formed at the end of Mesozoic: Proterozoic and Archean are the basement of the basin; Paleozoic and Mesozoic formed the structural layers of the basin, including Sinian, Cambrian, Lower Ordovician and Middle Ordovician, Upper Carboniferous, Permian, Triassic and local residual Jurassic. Cenozoic unconformity covered the basin. The top surface of Ordovician in the deepest part of the basin is about 2500m deep.
Coal measures: The coal measures in Qinshui coalfield belong to the Carboniferous-Permian coal measures in North China, and the coal-bearing strata include the late Carboniferous benxi formation and Taiyuan formations and the early Permian Shanxi and Xiashihezi formations.
Benxi formation: It is composed of mudstone, sandy mudstone, claystone, limestone and limonite interbedded with coal seams, with a group thickness of 10 ~ 50m.
Taiyuan Formation is composed of sandstone, mudstone, limestone and coal seam with alternating marine facies and a thickness of 50 ~ 150m. Generally, there are 7~ 10 layers in the coal seam, of which 3~5 layers can be mined, and the total thickness of the minable coal seam is 4~ 10 meters, which is thick in the north and thin in the south.
Shanxi Formation: It is composed of continental and coastal sandstone, mudstone with coal seam and thin limestone, with a thickness of 40 ~110m. There are 3~6 layers of coal seam, of which 2~4 layers are recoverable, and the total thickness of recoverable coal seam is 2~7 meters.
Lower Shihezi Formation: composed of continental sandstone and mudstone, with bottom 1~2 layers and thickness of 90 ~ 2 14m.
2. Coal resources
Coal resources in Qinshui coalfield
The amount is about 300 gt,186 Gt of proven coal reserves at the end of 1989, accounting for 9.58% of the whole country. Most of the unexplored predicted coal resources are reliable, and the buried depth is mostly less than 1000 meters. The coal is mainly anthracite, with a small amount of coking coal, lean coal and lean coal in the shallow part of the east, west and north margin, and anthracite in the deep part of the coalfield. Coal is mostly medium ash, with low sulfur content and high calorific value. Yangquan coal is a high-quality coal for blast furnace powder injection and sintering. Jincheng coal is a high-quality raw material for synthetic ammonia and nitrogen fertilizer; Lu' an specializes in coking coal and lean coal, which is high-quality coking coal blending. At the bottom and lower part of coal measures, there are many layers of pyrite, and some sections can reach industrial grade to extract sulfur and produce sulfuric acid; The lower part of coal measures also contains several layers of bauxite and clay rock, which can be used. Yangquan uses mine water to produce coal seam alkanes, which has a good utilization prospect and has been partially developed.
3. Geological conditions of mining
Qinshui coalfield has simple geological structural conditions, gentle dip angle of coal seam, undeveloped small mine structure, strong occurrence regularity, and most geological conditions in Wenshui are not complicated. The existing mine geological conditions in coalfields are among the best in China. Except for the high gas content in coal seams in Yangquan area in the northeast corner, some mines belong to high gas mines, a few are outburst mines, and most of the other mines in the coalfield are low gas mines.
4. Overview of development
Yangquan, Changzhi, Jincheng and other places had small kiln mining as early as the Ming Dynasty. So far, three large mining areas with an annual output of 10Mt have been formed. There are 7 state-owned mining bureaus and key coal mines in the coalfield, with a production capacity of 36.77Mt and an annual output of more than 40 mt.
Datong Coalfield: A multi-stage coalfield in the northern part of North China coal-accumulating area in China.
Jixi coalfield
Located in the northern part of Shanxi Province, it spans five cities and counties of Datong, Huairen, Yin Shan, Zuoyun and Youyu, with an oval plane and an area of 1828km2. It mainly produces high-quality thermal coal, and is the seat of Datong Mining Bureau, the largest coal producer in China.
1. Geological structure
Datong coalfield is a syncline tectonic basin in the northeast direction, and part of its surface is covered by Tertiary and Quaternary. The axis of syncline is Yungang Formation of Middle Jurassic (J 1t), and the wing strata include Datong Formation of Early Jurassic (J2y), Upper Shihezi Formation of Late Permian, Lower Shihezi Formation of Early Permian, Shanxi Formation, Late Carboniferous Taiyuan Formation, benxi formation C0, Ordovician and Cambrian. The northwest wing of syncline is gentle, and the dip angle is less than 10 degree, while the southeast wing is slightly steep, with a general dip angle of about 20 degrees. The strata near the syncline are vertical and inverted due to the south-dipping reverse fault. There are secondary small, wide and gentle folds in syncline, and small and medium faults are not developed. Small Yanshanian lamprophyres in Emeikou and Weijiadi areas in the southeast invaded Carboniferous and Permian.
2. Coal seam
Datong coalfield contains two sets of coal measures strata. ① Carboniferous-Permian coal measures, including benxi formation in the lower part of Upper Carboniferous, Taiyuan Formation in the upper part of Upper Carboniferous and Shanxi Formation in the lower Permian. ② Early Jurassic coal measures, namely Datong Formation of Lower Jurassic. Benxi formation does not contain minable seam. Taiyuan Formation is composed of continental and coastal sandstone, mudstone mixed with coal seam and kaolinite, with a thickness of 36 ~ 95m, of which recoverable and partially recoverable coal seam 10, and the total thickness of coal seam is more than 20m. Shanxi Formation is composed of continental sandstone with coal and mudstone, with a thickness of 45 ~ 60m, containing 1 minable seam and a thickness of 0 ~ 3.8m Datong Formation is composed of continental sandstone with mudstone and coal seam, with a thickness of 0 ~ 264m (generally 220m), in which minable seam 14 ~ 2 1 layer. ..
3. Resources
The coal resources in Datong Coalfield are about 42Gt, and the proven coal reserves reach 35Gt. Among them, the proven reserves of early Jurassic coal are about 7Gt, and the coal type is low ash, low sulfur and weak viscosity coal, which is a famous high-quality power coal in China. The proven reserves of Carboniferous and Permian coal are about 28Gt, and the predicted resources in the deep coal field are nearly 7Gt. The coal types are gas coal and gas fat coal, with high ash content and low sulfur content, which are power coal. There are bauxite and limonite layers at the bottom of Carboniferous-Permian coal measures, and their composition and quality change greatly, only reaching the recoverable grade locally. There are several layers of high-order rocks (commonly known as black sandstone) in the Carboniferous-Permian coal measures, which have good development prospects.
4. Geological conditions of mining
Early Jurassic coal seams in Datong coalfield are shallow buried, with flat corners and few faults. Most coal seams are medium-thick coal seams, and the underground mining conditions are good, but there are also the following problems. (1) The roof of coal seam is generally thick layered sandstone, which has high compressive and tensile strength and is not easy to fall. When the roof weighting in goaf is heavy, the sudden collapse of hard roof in a large area will cause serious disasters. (2) The lack of groundwater and surface water in coalfields seriously affects the water supply in mining areas; Mine hydrogeological conditions are simple, but a large amount of ancient kiln water poses a great threat to mining. (3) Although the gas content in the mine is low in the south and high in the north, the northern part of Xinzhou Kiln Mine is a gas-rich mine, which is in danger of gas outburst. (4) Spontaneous combustion of coal seam is common. At present, the development of Carboniferous-Permian coal seams in Datong coalfield is limited to the shallow part. Besides simple roof management, gas, spontaneous combustion of coal seam and floor management are more complicated than early Jurassic coal seam mining.
5. Overview of development
Coal mining in Datong coalfield began in the Southern and Northern Dynasties. At present, the early Jurassic coal seams have all been developed in stages; Carboniferous and Permian coal seams have also been mined. In recent years, the annual output of coal in the whole coalfield is nearly 70MT. Among them, the production capacity of Datong Mining Bureau accounts for nearly half. 1. energy radiation-large thermal power generation group.
Zhungeer Coalfield is located at the junction of Shanxi, Shaanxi and Mongolia. It is one of the four famous open-pit coal mines in China and a super-large comprehensive energy base in western China. ?
After China joined the WTO this year, with the acceleration of investment and development of key projects in western provinces and regions and the strong demand for electricity in Beijing, Tianjin and Tangshan, new energy has become the focus of people's general attention. Zhungeer coalfield is rich in clean energy and long-flame thermal coal, which has become a promising target for power enterprises. Recently, the second phase project of Tuoketuo Power Plant in Inner Mongolia and Daihai large-scale thermal power plant have been approved by the State Planning Commission. Together with the first-phase project of Tuoketuo Power Plant in Inner Mongolia and the second-phase project of Guohua Zhungeer Power Plant currently under construction, * * * isomorphism has become a huge potential demand for coal in Zhungeer coalfield. In this way, including Shenhua Zhungeer No.1 Power Plant, Fengzhen Power Plant in Inner Mongolia, and power plants along Beijing-Baotou, such as Shalingzi and Douhe in North China, these units objectively formed a large-scale thermal power generation group radiating around Zhungeer coalfield. It is estimated that by the end of the Tenth Five-Year Plan, the power of power plants designed according to the coal quality of Zhungeer coalfield will reach more than 5 million kilowatts, and the demand for thermal coal in Zhungeer coalfield will reach about 30-35 million tons. Thus, Zhungeer coalfield, as an upstream enterprise of industrial construction in ethnic areas, plays an important role in the western development. ?
Zhungeer Coalfield has proven reserves of 26.76 billion t, and its service life is 1 15 years. Its large-scale development and construction began in the 1990s. Zhungeer Energy Company (formerly Zhungeer Coal Company), as a large national group enterprise, spent 10 years and invested10 billion yuan. By the beginning of this century, a new coal city has been built, which integrates raw coal mining, washing, pit power generation and road-port combined transport, with the advantages of multi-industry development and self-sufficiency in production and marketing. Especially during the first phase of Zhungeer Project, hundreds of billions of dollars have been invested to introduce world-class mining, transportation and processing equipment from abroad, and the production efficiency has reached the leading level in the same industry in China. ?
2 environmental protection coal-a hot commodity in the market
The coal quality of Zhungeer coalfield has the natural conditions of ultra-low sulfur, low phosphorus, high ash melting point, high calorific value and high volatile matter, and is most suitable for power coal and chemical fuel. It is famous for its low pollution and is favored by users in the coal sales market, and is known as "green coal coke". Not only does it occupy a large market share in the northeast, north China, east China and southeast coastal areas, but it is also very popular in Shanghai, Fujian, Xiamen and other cities with strict restrictions on fuel sulfur content, because its sulfur content is less than 1%. In March this year, some cleaned coal was shipped to Morocco in North Africa to compete in the international coal market. At present, the export channels that have been opened mainly include Qinhuangdao Port, Tianjin Port, Daqin Line, Beijing-Baotou Line and Jitong Line. Nearly 30,000 tons of commercial coal are sold to stable contract users everywhere every day. In July, it set a foreign sales record of 720,000 t.
Jixi coalfield
From June to September this year alone, the sales volume reached 5.5 million t, the sales income was 654.38 billion yuan, and the profit was 654.38 billion yuan. "Green Coal" has also registered a national trademark, and CCTV has also made an in-depth report on the measures taken by Zhungeer Energy Company to implement the famous brand strategy. Later, Germany, Japan, South Korea, Thailand and other Southeast Asian countries and regions sent consulting books to pay attention to "Zhungeer Green Coal", and Malaysian merchants also made a special trip to Heidaigou open-pit coal mine in Zhungeer coalfield for field investigation. ?
3 scale effect-the implementation of sustainable development strategy
With the good market situation of "green coal" at home and abroad, a number of consolidated large coal users, such as Datang Company and Zhunneng Company, have formed a long-term strategic partnership. At this year's national coal ordering meeting, there were 14 new customers, and the resulting contradiction between production, transportation and marketing became increasingly apparent. In order to expand the production scale and improve the production and transportation capacity, Zhunneng Company will seize the opportunity of coal-electricity energy conversion and clean coal technology in the future, and at the same time, take advantage of the current production efficiency to reach the output, tap the potential ahead of time and meet the challenge of western development. ?
Zhunneng Company invested 80 million yuan in 1999 to expand and transform the coal preparation plant with an annual output of120,000 tons of commercial coal, and changed the jigging and washing process into an advanced dense medium process. The classification washing capacity of coal preparation plant has been greatly improved. According to the market and user demand, the heating value of washing is 18? 8 1~27? 17MJ/kg, realizing automatic train loading. ?
In order to meet the large coal demand of many customers during the Tenth Five-Year Plan period, we are raising 1 100 million yuan through the reform of the enterprise's own railway shares, introducing the world's most advanced mining and transportation equipment and its supporting equipment to replace the existing forklift and single bucket transportation technology, reducing transportation consumption and matching the raw coal production capacity with the market demand level. With the improvement of scale efficiency and the reduction of cost, "green coal" is more competitive in the market. At the same time, according to the adjustment of market changes, Halwusu, the second largest open pit mine, will start mining at an appropriate time. In order to solve the shortage of railway transportation capacity, it is currently being demonstrated that Zhungeer River (Qu) Railway will be connected with Shenshuo Railway of Shenhua Group to realize internal railway network transportation. By then, the export of coal can take the Shuohuang line again and open up the second largest channel for sending coal from west to east, which can not only alleviate the shortage of transportation capacity of Daqin line, the first largest channel, but also carry out coal transportation and marketing with Shenhua. It is estimated that the company's own railway transportation will increase the benefit by 40 million yuan every year. By the end of the Tenth Five-Year Plan, the coal flow in Zhungeer Coalfield has been divided into three channels (Daqin Line, Huangshuo Line and Jitong Line) and four ports (Qinhuangdao Port, Tianjin Port, Huanghua Port and Jingtang Port). The overall strength and benefit of the company have been greatly improved, and sustainable development and diversified management have been realized.
4 regional economy-a new economic growth point
Zhungeer coalfield, as a key state-owned enterprise in Inner Mongolia, is also a big profit and tax collector. During the "Ninth Five-Year Plan" period, the accumulated local profits and taxes were 340 million yuan, which was as high as 65438+300 million yuan in 2000 alone, especially for the large-scale development and construction of Zhungeer coalfield. The total investment of the first phase project is 9.26 billion yuan, and a considerable part of the construction funds are used in this area, which has promoted the rise of related industries such as construction, transportation, catering, real estate, manufacturing and processing in this area. It has formed a unique regional economic phenomenon that takes the emerging mining area economy as the link and drives the rapid economic development of the surrounding ethnic minority areas. In particular, the opening of Datong-Zhunzhun (Geer) enterprise railway, which is 264 kilometers long and passes through five counties and cities in two provinces, has broken the passive situation of traffic congestion and backward information in this area for many years, and has shown infinite vitality for farmers and herdsmen in the old, less, marginal and poor areas along the line to get rid of poverty and become rich. ?
In the past, Xue Jiawan, a small place with only a dozen families, has now become a new Zhungeer mining area with a population of nearly 654.38 million. Zhungeer Railway and Zhungeer East (Sheng) Railway, which are about to be completed in an all-round way, pass through it, and Zhungeer River (Qu) and Zhungeer Hohhot (City) Railway, which are currently being planned and constructed, are also in line with it, becoming the hub station of comprehensive railway transportation in western China. The special geographical advantages of the intersection of the three provinces in the mining area, through the communication between Wanjiazhai Water Control Project and the Yellow River Bridge, have formed a highway network extending in all directions with Hebei, Shanxi and Beijing provinces. It is precisely because of the strong economic development momentum in the mining area that the people's government of Zhungeer Banner also moved to the mining area of Zhungeer Banner, where enterprises and localities jointly developed and introduced foreign development funds. 200 million yuan, forming a good investment environment, which has injected new vitality into the local economic development. ?
Large-scale energy bases, emerging modern coal cities, mining areas jointly developed by enterprises and land, rapid development and distinctive regional economy have become another highlight of the great development of the western region of the motherland. The largest multi-stage coalfield in China, one of the super-large coalfields in the world, spans Shaanxi, Gansu, Ningxia, Inner Mongolia and Shanxi provinces, with a width of 400KM from east to west and a length of 600KM from north to south, with a slightly rectangular plane. "Ordos" means "many palaces" in Mongolian. The area south of the Yellow River Hetao, north of Weihe Plain, west of Luliang Mountain and east of Helan Mountain is called Ordos platform in geological circles, and the scope of this coalfield is roughly equivalent to it. The coal-forming periods of Ordos coalfield include Permian, Late Triassic and Middle Jurassic. According to the distribution of coal-bearing rock series, coalfields can be divided into three coal-bearing zones. (1) East Zone. Carboniferous and Permian coal producing areas, including Zhungeer, Hedong and Weibei. (2) the western belt. Coal-producing areas are mainly Carboniferous and Permian, including Table Mountain, Helan Mountain and Weizhou. And Rujigou, scattered middle Jurassic coal-producing areas. (3) the middle belt. Dongsheng, Shenmu and other middle Jurassic and Zichang and Niuwu in the east are the producing areas in the Late Triassic. There are middle Jurassic coal-producing areas in Lingwu and Guyuan on the west; There are middle Jurassic coal-producing areas such as Huangling, Binxian, Longxian and Huating in the south.
geologic structure
The coalfield is a nearly north-south structural basin, with the syncline axis located in Huan County, Ningxia-Gansu Province, and the east wing is gentle (20℃). The axis is composed of Cretaceous, and Jurassic, Triassic, Permian, Carboniferous and Ordovician are distributed to the two wings in turn. Syncline is covered by Cenozoic unconformity. Late Paleozoic and Mesozoic strata were formed in a wider sedimentary basin pattern in North China, and coal measures were preserved. The tectonic conditions of the whole basin are simple, especially the small and medium-sized fold faults in the east wing. Carboniferous and Permian coal measures include four groups of coal-bearing strata: benxi formation (Yanghugou Formation) and Taiyuan Formation in Late Carboniferous, Shanxi Formation and Xiashihezi Formation in Early Permian. See table 1 for coal seam conditions.
The coal measures of the Late Triassic Wayaobao Formation belong to the top horizon of the Upper Triassic Yanchang Formation, and consist of continental sandstone, mudstone containing coal seam and oil shale and local mudstone lens, with a thickness of 186-4 12M. Mineable coal seams are only distributed in Zichang County and Niuwu in Fuxian County. The maximum number of coal seams is 32, but most of them are thin coal seams, only two layers are recoverable, and the total thickness of recoverable coal seams is 0.31-4.66 m.
The middle Jurassic coal measures are called Yan 'an Formation, which is composed of continental sandstone, shale and clayey rock sandwiched with coal seams, with a thickness of 60-6 18M. There are no coal seams in this group except in the south of Dali River, north of Hulu River and east of Wuqi County in northern Shaanxi, and there are minable coal seams in other areas of the coalfield (Table 2).
resources
The coal resources in the whole coalfield are about 1800 gt, of which1000 m is relatively shallow, about 650GT. By the end of 1989, the proven reserves totaled 346.4GT, and the proven reserves in each coal-producing area were: Zhungeer 25.3GT, Hedong 50.3GT, Weibei 6.2GT, Dongsheng 73.3GT, Shanbei 135.7GT, sub-length 0.8GT and Huangling14 respectively.
Coalfield is also a large petroliferous basin. In addition to the discovery of many small and medium-sized oil fields in Huachi-Huanxian and Yinchuan-Lingwu areas in the central and western regions and the distribution of many small and medium-sized gas fields in the whole basin, the proven natural gas reserves in Jingbian-Hengshan area in recent years are 100 gm3, which is the largest natural gas field on land in China.
Properties of coal
(1) Carboniferous-Permian coals are mostly medium ash rich coals and low-high sulfur coals. Generally speaking, Shanxi Formation mainly produces low-sulfur coal, while Taiyuan Formation mainly produces high-sulfur coal. Except Zhungeer in the north is long-flame coal, other coal-producing areas are bituminous coal. The degree of rank metamorphism in the eastern belt increases from north to south: the northern part of Hedong coal producing area (Fugu-Lishi) is gas coal, the southern part (Lishi-Xiangning) is fat, coke and lean coal, and Weibei coalfield is thin and lean coal (deep anthracite). Most of the coal in the western region belongs to gas, fertilizer and coking coal. Lishi, Liulin and Xiangning in the southern section of Hedong coal-producing area are the main coking coal bases in China. (2) Late Triassic coal belongs to middle-low ash and middle sulfur coal, which is gas coal. (3) Middle Jurassic coal belongs to low-ash and low-sulfur coal, except for anthracite in Rujigou and some gas coal in Huangling, the rest are non-sticky, weakly sticky or long-flame coal. Dongsheng and northern Shaanxi in the northern part of the coalfield have extremely low ash content, which is a famous producing area of high-quality thermal coal in China. Rujigou has also become a famous anthracite producing area with ultra-low ash and high quality.
Mining conditions
The geological structure and hydrogeological conditions in most areas of the coalfield are very simple, which is the most suitable place for coal mining in China. The medium and small faults in Weibei, Helanshan and Zhuozishan coal-producing areas are more complicated. The middle and deep part of Weibei (below +380M above sea level) is also threatened by Ordovician limestone water. In the shallow buried part of coal measures strata, the dip angle of coal seam is gentle, which is suitable for the construction of open-pit mines (Zhungeer, Dongsheng, northern Shaanxi, Huangling, etc.). ). The existing mining mines are shallow, and most of them are low gas mines for the time being. Only Shizuishan mining area has gas outburst. Because methane in coal seam increases with depth, it is estimated that the risk of gas outburst will increase in the future. Coal dust explosions have occurred in Weibei, Helan Mountain and Hedong. Spontaneous combustion is very common in middle Jurassic coal seams; Except Helanshan mining area, Carboniferous and Permian coal seams generally do not spontaneously combust.
General situation of development
Since the Song Dynasty, there have been coal mining activities in Weibei, Hedong, Helan Mountain and other places, and traces of coal mining during the Warring States Period have also been found in Weibei. At present, nine mining bureaus have been built in the coalfield, with an annual coal output of over 30MT, including coal mines with various management systems and scales. In recent years, the annual output of coal is nearly 65,438+000 mt. With the strategic shift of China's coal industry to the west, this coal field has become the focus of the national coal industry construction. There are also large coal bases under construction: Zhungeer (open-air), Liu Li, Dongsheng, Shenmu and Huating. Huainan Coalfield: Carboniferous-Permian Coalfield in the south of North China coal-accumulating area in China. Located in the north-central part of Anhui Province, with Huainan as the main body, it extends to Chu County in the east and Fuyang in the west. Its plane is a long ellipse in the northwest direction, about 100km long, 20 ~ 30 km wide and 2500km in area. Coalfield straddles the banks of Huaihe River, so it is named Huainan Coalfield because its discovery and development began in the south bank. After exploration, coal was found in a larger area on the north bank of Huaihe River, but its original name was still used.
1. Geological structure
Huainan coalfield is a NW-trending syncline structure, which is mainly composed of Upper Paleozoic. Lower Paleozoic is located in the south and north of coalfield, which is generally covered by Quaternary. There are low-angle strike reverse faults in the southern and northern margins of the coalfield, which caused the lower Paleozoic and the upper Paleozoic to overlap many times. A group of ne-trending normal faults developed in the syncline cut the Upper Paleozoic into stepped blocks. Carboniferous and Permian coal measures widely exist in synclines and often form secondary folds. During Yanshanian magmatism, fine fine-grained rocks, lamprophyres and bedrock invaded coal measures strata, affecting local coal seams.
Coal measures The coal-bearing strata in Huainan Coalfield are Carboniferous-Permian coal measures in North China, including: late Carboniferous benxi formation and Taiyuan Formation, early Permian Shanxi Formation and Xiashihezi Formation, and late Permian Upper Shihezi Formation. The main coal-bearing strata are Upper Shihezi Formation, Lower Shihezi Formation and Shanxi Formation of Permian, and the Carboniferous strata basically contain no minable coal seams.
Benxi formation: It is composed of shallow sea facies, offshore facies, thin limestone and iron-bearing claystone, and its thickness is generally 5- 10m.
Taiyuan Formation: consists of shallow marine limestone, mudstone, sandstone and thin coal seam. Limestone 10 ~ 13 layer, thin coal seam 8 ~ 1 1 layer, of which 1-2 layer is locally recoverable. Generally, the thickness of the whole group is 100 ~ 120m.
Shanxi Formation: It is composed of coastal sandstone, mudstone and coal seam, generally 60 ~ 70m thick, of which coal seam 1 ~ 3, with a total thickness of about 7m.
Lower Shihezi Formation: composed of continental mudstone, siltstone, sandstone, oolitic mudstone and coal seam, with a thickness of 100 ~ 150m. The coal seam contains 13 ~ 16 layers, most of which are recoverable, with a total thickness of18.73m.
Upper Shihezi Formation: composed of continental sandstone and mudstone, the middle and lower rocks are gray, and the total thickness of coal seam is 13.09 m; The upper rock is red, green, yellow and other variegated tones, containing 3~5 thin coal seams, which is not recoverable. The whole group is 600~800 meters thick.
2. Resources
There are about 66 coal resources in Huainan coalfield, the proven coal reserves are about 15, the basic buried depth of the unproven coal seam is over 1 1,000 m, and the old mining area south of Huaihe River produces coking coal 1/3 and a very small amount of gas coal. Panji mining area, north of Huaihe River, mainly produces gas coal; The ash content in coal is mostly medium and high, and the sulfur content is generally low, which is a good coking coal. There are * * * refractory clay minerals in coal measures. There are 6 proven reserves in Xiejiaji-Xinzhuang area, and the deep gas content in Huainan old mining area is high, which has a good prospect of drainage and utilization.
3. Geological conditions of mining
Huainan coalfield is dominated by medium-thick inclined coal seams with moderate structural complexity, and the general mining conditions are acceptable. Quaternary unconsolidated layer is 0~800 meters thick, thickened from east to south to north, and contains gravel and quicksand layer. Building a well requires a special sinking method. Mine water filling is mainly the infiltration of atmospheric precipitation and Quaternary sand water, and the hydrogeological conditions are relatively simple. However, the limestone karst water in Taiyuan Formation is complex, with inversion or faults in the stratum, which has an impact on the mining of Permian coal seams. Urumqi coalfield: an important Jurassic coalfield in northern China. Located in the south of Junggar basin in Xinjiang, the plane is strip-shaped, about 400km long from east to west, and Urumqi is located in the east of the middle of the coalfield. There are five coal-producing areas, namely Shuixigou, Shekang, Urumqi, Manas and Xisumu from east to west. Urumqi coal-producing area in the east of coalfield is the main production mining area at present.
1. Geological structure
The coalfield is located in Junggar Mesozoic-Cenozoic basin, with linear flexure and fold development in the southwest of the basin. The folded crankshaft inclines to the southeast, and local strata are vertical or inverted. Medium and small fault structures are medium to simple. The coal measures strata belong to the Middle-Lower Jurassic, and the lower part is the Badaowan Formation of Early Jurassic, which is composed of continental sandstone and mudstone sandwiched with coal seams, with a thickness of about 1000 m, of which coal seams/kloc-0 ~19, and the average total thickness of minable coal seams is10.70 ~19. The upper part of 466866 is the Xishanyao Formation of Middle Jurassic, which is composed of sandstone and mudstone sandwiched with coal seams. There are 28 ~ 39 coal seams, and the average total thickness of minable coal seams is 97.88 ~134.70m ... Most coal seams are medium to thick, but 1 ~ 3 extra-thick coal seams are commonly developed, and the thickness can reach 30~50m. The coal seam in Urumqi coal-producing area is the most developed, and the coal-bearing property extends to the east and west sides and gradually becomes worse.
2. Coal resources
The coal resources are about 100Gt, and the proven coal reserves are about 4Gt. Most of the coal types are long flame coal, some are weakly sticky coal or non-sticky coal, and some are gas coal. The ash and sulfur content of coal are generally low, and a few have medium ash content, so it is an excellent fuel coal. There are 5 ~ 23 layers of oil shale in the Late Permian Lucaogou Formation on the south side of the coalfield, with a total thickness of 34 ~ 66 m, which has the prospect of development and utilization.
3. Mining conditions
Coalfield is rich in coal resources, the coal density is as high as 60Mt/km2, and its geographical position is superior. Although the coal seam is mostly steep, it is thick, with relatively simple structure, relatively stable roof and good development conditions. The shallow part of some sections can still be mined in the open pit. Mine water is mostly fissure water, which is mainly replenished by surface water along the coal seam, and the hydrogeological conditions are simple. Mine gas content is not high, which generally belongs to low gas mine. Coal dust has certain explosion danger, and coal dust explosion happened in Jiudaowan Coal Mine. Spontaneous combustion of coal is common, and there are basically fire areas in the shallow part of existing production wells.
4. Overview of development
The coal produced in Urumqi coalfield is basically supplied to land or adjacent areas, and the degree of development is relatively low. There are mainly Urumqi in the local area; Bureau, under the jurisdiction of five coal mines, the annual output of about 2 mt, the annual output of local and township coal mines13.54Mt at the end of 985.