The Kailuan Coalfield is a famous Shiyan Permian coalfield in the Huaju Coal Region of China, rich in high-quality coking coal. It is located in the eastern part of Hebei Province, spanning 5 cities and counties including Tangshan, Luanxian, Luannan, Fengrun, and Fengnan. It is a strip in the northeast direction and covers an area of ??550 square kilometers. The Jingshan Railway runs through the coal fields, and the Kailuan Mining Bureau is responsible for coal mining in the coal fields.
Geological structure: Kailuan Coalfield has a northeastern syncline structure, called Kaiping syncline. Its northeastern end rises and tilts toward the southwest. The southeastern wing has an inclination angle of about 20 degrees, and the northwest wing is slightly steeper. The axis of the syncline is composed of late Permian red and variegated strata, the wings are composed of rocky Permian coal measures, and the outer edge is composed of Ordovician limestone. The depth of the top surface of the Ordovician system in the axis is generally less than 2000 meters. The entire syncline is basically covered by the Quaternary System, and the covering layer thickens from northeast to south-west, reaching a thickness of more than 800 meters at the southwest end of the coalfield. In some sections of the southeastern wing of the syncline, Mesozoic diabase intrudes into the coal series and is produced in the form of rock walls and veins.
1. Coal Measures
① Tangshan Formation in the Late Carboniferous. It is composed of alternating marine and continental phases of mudstone and sandstone intercalated with thin layers of limestone and bauxite. It is 73 meters thick and contains 3 to 4 thin coal seams. ② Tangping Formation in the middle of Late Carboniferous. It is composed of thin layers of limestone and coal seams of alternating sea and land phases, and is 65 meters thick. ③The Zhaogezhuang Formation in the late Late Carboniferous. It is composed of continental and coastal facies sandstone and siltstone intercalated with coal seams, and is 79 meters thick. ④ Damiaozhuang Formation in the early Early Permian. It is composed of continental sandstone, siltstone, mudstone and coal seams, and is 74 meters thick. The entire coal system contains 18 coal seams, of which 5 to 7 are mineable and partially mineable coal seams. The total thickness of the mineable coal seams is meters.
2. Resources
The coal resources in Kailuan Coalfield are 10.8Gt, and the proven coal reserves are about 4Gt. The coal types are gas coal and fat coal! They are low-ash-rich and low-sulfur-rich coal. After washing, they become excellent coking coal. There are multiple layers of bauxite and clay minerals in the coal system and its overlying strata. Ceramics and refractory products have been developed and processed, and there are still prospects for further development. There are also development prospects for layered and nodular pyrite in the coal measures and coal seams
Jixi Coalfield
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3. Mining geological conditions
The coal seams in the Kailuan Coalfield are mainly medium-thick coal seams, with inclination angles ranging from gentle to steep, and the geological conditions are generally moderate. The hydrogeological conditions of the coalfield are complex. There are five main aquifers with abundant water. In particular, the karst fissure water in the Ordovician limestone underlying the coal measures poses the greatest threat to the mines. Water inrush and extremely large water inrush disasters have occurred many times. The gas content is higher in the mines on the northwest wing of the syncline, which are high gas mines and gas outburst mines; the gas content is lower on the southeast wing, which is generally low gas mines. The natural ignition period of coal seams is relatively long, and there is generally no spontaneous combustion.
4. Development overview
Historical records indicate that coal mining activities began in the Kailuan Coalfield in the Ming Dynasty. In 1878, Li Hongzhang and Tang Tingshu organized the Kaiping Coal Mine, which produced coal in 1881. Modern coal mining operations began after the Keelung Coal Mine in Taiwan. In 1900, the Kaiping Coal Mine was operated by British businessmen. In 1908, the Luanzhou Coal Mine was established. In 1912, the Kaiping and Luanzhou Coal Mines were merged into the Kailuan Mining Administration, which was operated by British businessmen. In 1949, the People's Republic of China and the National People's Congress After its establishment, it was taken over by the state. In the past 40 years, Kailuan Mining Bureau has carried out high-intensity mining by virtue of its location and transportation. At present, all the shallow coal resources in the coalfield have been used. Kailuan Mining Bureau has 9 production mines in the coalfield, with a total annual production capacity of 20.80MT and an annual coal output of nearly 16.00MT. The original Guogezhuang mine has been mined, and there is not much coal reserve left in the existing Tangjiazhuang mine. It will also be mined and scrapped. Kailuan Mining Bureau has opened coal producing areas such as Chezhuoshan and Linnancang to the west of Luan Coalfield for development and construction. Within the coalfield, there are also local coal mines for coal development, with an annual production capacity of approximately 1 million tons. Qinshui Coalfield is the largest Carboniferous Triassic coalfield in China that currently produces the most coal. It is located in the south-central part of Shanxi Province, between Taihang Mountain, Luliang Mountain, Wutai Mountain and Zhongtiao Mountain, and spans Taiyuan, Shouyang, Yangquan, Xiyang, Heshun, Zuoquan, Wuxiang, Qinxian, Changzhi, Gaoping, Jincheng, Yang There are more than 20 cities and counties in Chengdu, Qinshui, Anze and Qinyuan, covering an area of ??nearly 30,000 square kilometers. Large-scale mining bureaus such as Yangquan, Lu'an, and Jincheng have been built within the coalfield. There are more than hundreds of local coal mines. Coal development is extremely prosperous. It is the largest supply base of anthracite coal, chemical coal, and coking coal in China.
1. Geological structure
The Qinshui Coalfield is a structural basin formed at the end of the Mesozoic Era: the Proterozoic and Archaean are the base of the basin; the Paleozoic and Mesozoic constitute the basin's structures The layers include the Sinian, Cambrian, lower and middle Ordovician, upper Carboniferous, Permian, Triassic and partially remaining Jurassic systems; the Cenozoic unconformably covers the basin. The top surface of the Ordovician system in the deepest part of the basin is about 2,500 meters deep.
Coal Measures: The coal measures in the Qinshui Coalfield belong to the North China type Carboniferous-Permian coal measures. The coal-bearing strata include the Late Carboniferous Benxi Formation, Taiyuan Formation, and the Early Permian Shanxi Formation and Lower Shihezi Formation.
Benxi Formation: It is composed of alternating marine and continental phases of mudstone, sandy mudstone, claystone, limestone, and limonite layers interspersed with coal lines. The formation is 10 to 50 meters thick.
The Taiyuan Formation is composed of alternating marine and continental phases of sandstone, mudstone, limestone and coal seams, with a thickness of 50 to 150 meters. Generally, there are 7 to 10 layers of coal seams, of which 3 to 5 are mineable. The total thickness of the mineable coal seams is 4 to 10 meters, thick in the north and thin in the south.
Shanxi Formation: It is composed of continental and coastal sandstone, mudstone intercalated with coal seams and thin layers of limestone. The formation is 40 to 110 meters thick. There are 3 to 6 layers of coal seams, of which 2 to 4 are mineable. The total thickness of the mineable coal seams is 2 to 7 meters.
The Lower Shihezi Formation: It is composed of continental sandstone, mudstone, and 1 to 2 layers of coal line at the bottom. The thickness of the formation is 90 to 214 meters.
2. Coal resources
The coal resources of Qinshui Coalfield
are about 300Gt. By the end of 1989, the proven coal reserves were 86Gt, accounting for 9.58% of the country. Most of the unexplored predicted coal resources are of reliable grade, and most of them are less than 1,000 meters deep. The coal type is mainly anthracite. There are a small amount of coking coal, lean coal and lean coal in the shallow parts of the east, west and north edges. The deep part of the coalfield is all anthracite. Most coal has medium ash content, low to high sulfur content, and generally has a high calorific value. Yangquan coal is high-quality blast furnace powdering and sintering coal; Jincheng coal is a high-quality raw material for synthetic ammonia and nitrogen fertilizer; Lu'an's main coking coal and lean coal are high-quality coking blending coal. At the bottom and lower part of the coal series, there are multiple layers of pyrite, some of which reach industrial grade, which can be used to refine sulfur and produce sulfuric acid. The lower part of the coal series also contains several layers of bauxite and clay rock, which can be utilized. The coal bed methane drained from the Yangquan production mine has good utilization prospects and has been partially developed.
3. Mining geological conditions
The geological structural conditions of Qinshui Coalfield are simple, the coal seam inclination is gentle, the small mine structures are not well developed and their occurrence is very regular, and the Wenshui geological conditions are great. None of the parts are complicated, and the existing mine geological conditions in the coalfield are among the most superior in China. Except for the coal seam in the Yuyangquan area in the northeast, which has high gas content, some mines are high-gas mines and a small number are outburst mines, most of the remaining mines in the coalfield are low-gas mines.
4. Development overview
Yangquan, Changzhi, Jincheng and other places have had small kiln mining as early as the Ming Dynasty. Up to now, three large-scale mining areas with an annual output of more than 10Mt have been formed. In the coal fields There are seven state-owned mining bureaus and key coal mines in China, with a capacity of 36.77Mt and an annual output of more than 40Mt.
Datong Coalneld: a multi-year coalfield in the northern part of the coal-rich area in North China.
Jixi Coalfield
It is located in the northern part of Shanxi Province, spanning five cities and counties including Datong, Huairen, Shanyin, Zuoyun and Youyu. It is oval in plane and covers an area of ??1828km2. It mainly It produces high-quality thermal coal and is the location of Datong Mining Bureau, the largest coal production enterprise in China.
1. Geological structure
Datong Coalfield is a syncline structural basin with an axis to the northeast. , part of the surface is covered by the Tertiary and Quaternary systems. The syncline axis is the Middle Jurassic Yungang Formation (J1t), the wing strata include the Early Jurassic Datong Formation (J2y), the Late Permian Upper Shihezi Formation, and the Early Jurassic Yungang Formation (J1t). The Lower Shihezi Formation and Shanxi Formation of the Permian, the Taiyuan Formation and Benxi Formation C0 of the Late Carboniferous, and the Ordovician and Cambrian systems, etc. The northwest wing of the syncline is gentle, with an inclination angle of less than 10 degrees, and the southeastern wing is slightly steeper, with a general inclination angle of about 20 degrees. The near edge of the syncline is affected by reverse faults tilting to the south and the rock layers are upright and inverted. There are secondary small wide and gentle folds in the syncline, and medium and small faults are not very developed. In the southeastern Efeokou and Weijiadi areas, there are small Yanshanian lamprophyre dykes that intrude into the Carboniferous and Permian systems.
2. Coal Measures
Datong Coalfield contains two sets of coal measures. ①Carboniferous-Permian coal series, including the Benxi Formation in the lower part of the Upper Carboniferous, the Taiyuan Formation in the upper part of the Upper Carboniferous, and the Shanxi Formation in the lower Permian. ② Early Jurassic coal system, namely the Lower Jurassic Datong Formation.
The Benxi Formation does not contain minable coal seams. The Taiyuan Formation is composed of continental and coastal facies sandstone, mudstone intercalated with coal seams and kaolinite. The formation is 36 to 95m thick and contains 10 layers of recoverable and partially recoverable coal seams. The total thickness of the coal seams is more than 20m. The Shanxi Formation is composed of continental sandstone intercalated with coal and mudstone layers. The formation is 45-60m thick and contains 1 mineable coal seam, 0-3.8m thick. The Datong Formation is composed of continental sandstone intercalated with mudstone and coal seams. The thickness of the formation is 0-264m (generally 220m), and contains 14-21 minable coal seams. The total thickness of the minable coal seams is 18.7-24m.
3. Resources
The coal resources in Datong Coalfield are about 42Gt, and the proven coal reserves are 35Gt. Among them, the proven reserves of Early Jurassic coal are about 7Gt. The coal type is weakly caking coal with low ash and sulfur content. It is a famous high-quality power coal in China; the proven reserves of Carboniferous Permian coal are about 28Gt, deep in the coalfield. There are still nearly 7Gt of predicted resources. The coal types are gas coal and gas-fertilizer coal, with medium to high ash content and low to high sulfur content, which are used for power coal. At the bottom of the Carboniferous Permian coal measures, there are also bauxite and limonite layers, whose composition and quality vary greatly, and only partially reach recoverable grades. There are several layers of Koringite (commonly known as black sandstone) sandwiched in the Carboniferous Permian coal measures, which have good development prospects.
4. Mining geological conditions
The Early Jurassic coal seams in the Datong Coalfield are shallowly buried, have gentle angles, and have few faults. Most of the coal seams are medium-thick and thick coal seams, and the underground mining conditions are good. , but there are also the following problems. (1) Coal seam roofs are generally thick-layered sandstone, which has high compressive and tensile strength and is not easy to fall off. When the goaf roof comes under pressure, a large area of ??the hard roof suddenly falls off, which will cause serious disasters. (2) The lack of groundwater and surface water in the coalfield seriously affects the water supply in the mining area; the hydrogeological conditions of the mine are simple, but the large amount of water accumulated in ancient kilns poses a great threat to mining. (3) Although the mine gas content is low in the south, it is high in the north. The mines north of Xinzhouyao Mine are all high-gas mines, and there is a risk of gas outbursts. (4) Natural coal seam fires are common. The current development of the Carboniferous Permian coal seams in the Datong Coalfield is limited to the shallow part. In addition to simple roof management, gas, natural coal seam ignition, floor management, etc. are all more complicated than mining the Early Jurassic coal seams.
5. Development overview
Coal mining in Datong Coalfield began around the Northern and Southern Dynasties. At present, all the Early Jurassic coal seams have been developed in pieces; the Carboniferous Permian coal seams have also begun to be mined. In recent years, the annual coal output of the entire coalfield has reached nearly 70MT. Among them, the production capacity of each bureau of Datong Mine accounts for nearly half. 1. Energy radiation-large thermal power generation group
The Jungar Coalfield, located at the junction of Shanxi, Shaanxi and Mongolia, is a famous 4 It is one of the largest open-pit coal mines and a large comprehensive energy base in western my country. ?
After my country joins the WTO this year, with the accelerated pace of investment and development in key projects in western provinces and regions, as well as Beijing’s successful Olympic bid and the strong power demand in the Beijing-Tianjin-Tangshan region, new energy has become the focus of widespread attention. The Jungar Coalfield, which is rich in clean long-flame thermal coal, has become a promising target for power companies. Recently, the second phase project of Inner Mongolia Tuoketuo Power Plant and Daihai Large Thermal Power Plant have been approved by the State Planning Commission. Together with the first phase project of Inner Mongolia Tuoketuo Power Plant and the second phase project of Guohua Zhungeer Power Plant currently under construction,* The combination constitutes a potential and huge demand for coal in the Jungar Coalfield. In this way, including the currently operating Shenhua Zhungar Power Plant, Fengzhen Power Plant in Inner Mongolia, and power plants along the Beijing-Baotou line such as Shalingzi and Douhe in North China, these units have objectively formed a power plant with the Zhungar Coalfield as the axis and surrounding areas. A large thermal power generation group radiates in the area. It is estimated that by the end of the “10th Five-Year Plan”, power plants designed according to the coal quality of the Jungar Coalfield will reach more than 5 million kW, and the demand for thermal coal in the Jungar Coalfield will reach about 30 to 35 million tons. It can be seen that the Jungar Coalfield, as an upstream enterprise for industrial construction in ethnic minority areas, plays a decisive role in the development of the western region. ?
The Jungar Coal Field has proven reserves of 26.76 billion tons and a service life of 115 years. Its large-scale development and construction began in the 1990s. As a large national group enterprise, Zhungeer Energy Company (formerly Zhunge Coal Company) spent 10 years and invested tens of billions of employees to build a complex integrating raw coal mining and washing, pit mouth power generation, and road and port intermodal transportation by the beginning of this century. It is an emerging coal city with the advantages of developing multiple industries simultaneously and having its own system of production, transportation and marketing.
Especially during the construction of the first phase of the Jungar Project, billions of US dollars were invested to introduce world-class mining, transportation and processing equipment from abroad, and its production efficiency reached the leading level in the domestic industry. ?
2 Environmentally friendly coal - a hot commodity on the market
The coal quality of Zhungeer Coalfield has extremely low sulfur, low phosphorus, high ash melting point, high calorific value and high volatile matter. The natural conditions are the most suitable for use as thermal coal and chemical fuel. It is famous for its low pollution and is very popular among users in the coal sales market. It is known as "green and environmentally friendly coal". Not only does it have a large market share in Northeast, North China, East China and the southeastern coastal areas, but also because the sulfur content is less than 1%, it is very popular in Shanghai, Fujian, Xiamen and other cities that strictly limit fuel sulfur content. In March this year, some of the washed clean coal was shipped in containers and shipped to North Africa and Morocco to participate in the competition in the international coal market. At present, the export channels that have been developed mainly include Qinhuangdao Port, Tianjin Port, Daqin Line, Beijing-Baotou Line, Jitong Line and other sea and land transportation routes. Nearly 30,000 tons of commercial coal are sold to stable contract users in various places every day. In July, the external sales volume reached a historical record of 720,000 tons.
Jixi Coalfield
The sales volume from January to September this year alone reached 5.5 million tons, achieving sales revenue of 1 billion yuan and making profits of more than 10 million yuan. "Green Coal" has also been registered as a national trademark, and CCTV has also made an in-depth report on Zhungeer Energy Company's implementation of its famous brand strategy. Afterwards, Southeast Asian countries and regions such as Germany, Japan, South Korea and Thailand sent letters of inquiry, paying attention to "Zhungar Green Coal". Malaysian businessmen also made a special trip to the Heidaigou open-pit coal mine in the Jungar Coalfield for on-site inspections. ?
3 Scale effect-implementing sustainable development strategy
With the promising market conditions of “green and environmentally friendly coal” at home and abroad, a group of consolidated large coal consumers have been formed. , like Datang Company and Zhuneng Company have formed a long-term strategic partnership. At this year's National Coal Order Fair, 14 new customers were added, and the resulting contradictions between production, transportation, and sales have become increasingly apparent. In order to expand the scale of production and improve production and transportation capabilities, Zhuneng Company seizes the opportunity of coal-to-electricity energy conversion and clean coal technology in the future. While the existing production efficiency reaches full capacity, it will take advantage of the situation and tap the potential in advance to prepare for the Great Western Conference. Development challenges. ?
In 1999, Zhuneng Company invested 80 million yuan to expand and transform the coal preparation plant with an annual output of 12 million tons of commercial coal, and replaced the jig washing process with advanced heavy media technology. This greatly improves the coal preparation plant's grading and washing capabilities. Currently, various varieties with calorific value ranging from 18 to 81 to 27 to 17 MJ/kg can be selected according to market and user needs, and fully automated train loading has been achieved. ?
In order to meet the large demand for coal from many customers during the "Tenth Five-Year Plan" period, we are currently raising 1 billion yuan through the company's self-owned railway stock reform and listing, and introducing the world's most advanced mining and transportation equipment, bucket shovels and Its auxiliary equipment replaces the current forklift and single-bucket transportation processes, reducing transportation consumption and matching raw coal production capacity with market demand levels. With the improvement of scale efficiency and reduction of costs, "green and environmentally friendly coal" will become more competitive in the market. At the same time, according to market changes, the second largest open-pit mine, Harwusu, will be developed at the appropriate time. In order to solve the constraints of tight railway transportation capacity, the preparations for the construction of the Zhun (Ger) River (Qu) Railway are currently being discussed to connect with the Shenhua Group's Shenshuo Railway to achieve internal railway network transportation. By then, export coal can be exported via the Shuohuang Line, opening up a second major channel for transporting coal from the west to the east. This will not only alleviate the tight capacity conflict of the first major channel, the Daqin Line, but also enable internal coal distribution with Shenhua. It is expected that the company will Preparing railway transportation can increase benefits by 40 million yuan per year. By the late "Tenth Five-Year Plan" period, the coal flow direction of the Zhungeer Coalfield was through three major channels (Daqin Line, Shuohuang Line, and Jitong Line) and four major ports (Qinhuangdao Port, Tianjin Port, Huanghua Port, and Jingtang Port). The company's The overall strength and efficiency have been greatly enhanced, achieving sustainable development and diversified operations.
4 Regional economy - a new economic growth point
As a key state-owned enterprise in Inner Mongolia, Zhungeer Coalfield is also a large profit and tax company.
During the "Ninth Five-Year Plan" period, a total of 340 million yuan in profits and taxes were paid to local governments, reaching 130 million yuan in 2000 alone. Especially for the large-scale development and construction of the Zhungeer Coalfield, the total investment in the first phase of the project was 9.26 billion yuan. A considerable part of the construction funds have been spent in the region, driving the rise and development of construction, transportation, catering, real estate, manufacturing and processing and other related industries in the region, and showing an upward trend year by year. It has formed a unique regional economic phenomenon that uses the emerging mining area economy as a link to promote the rapid economic development of surrounding ethnic minority areas. In particular, the opening of the 264km-long Da (Tong) Zhun (Ger) Enterprise Railway, passing through 2 provinces and 5 counties and cities, has broken the passive situation of traffic congestion and backward information in the region for many years, and provided services for the elderly, young, border and poor people along the line. The farmers and herdsmen in the region have shown unlimited vitality in getting rid of poverty and becoming rich. ?
Xuejiawan, a tiny place with only a dozen households in the past, has now become an emerging Jungar mining area with a population of nearly 100,000. The Dazhun Railway and the Junger (Ger) East Railway are about to be fully connected. The (Sheng) Railway crosses it, and the Zhun (Ger) River (Qu) and Zhun (Ger) Hu (City) Railways currently under planning and construction are also connected with it, making it a hub station for western railway intermodal transportation. The special advantage of the geographical location at the intersection of the three provinces in the mining area is communicated through the Wanjiazhai Water Conservancy Project and the Yellow River Bridge, and it forms a road network extending in all directions with Hebei, Shanxi and Beijing provinces and cities. This is precisely because of the strong economic development of the mining area. situation, the People's Government of Zhungar Banner also relocated to the Zhungar Mining Area, enterprises and local governments jointly developed, and introduced more than 820 million yuan in foreign development funds, forming a good investment environment, all of which injected injection into the local economic development. New energy. ?
Large-scale energy bases, emerging modern coal cities, mining areas jointly developed by enterprises and localities, and rapidly developing and quite unique regional economies, together constitute another new step in the development of the western part of the motherland. Highlights. China's largest multi-epoch coalfield, one of the world's largest coalfields, spans the five provinces of Shaanxi, Gansu, Ningxia, Inner Mongolia and Shanxi. It is 400km wide from east to west and 600km long from north to south. The plane is slightly rectangular. "Ordos" means "many palaces" in Mongolian. In geological circles, the area south of the Yellow River Hetao, north of the Weihe Plain, west of the Luliang Mountains, and east of the Helan Mountains is called the Ordos platform. The scope of this coalfield is roughly equivalent to this. The coal-forming periods of the Ordos coalfield include the Paleocarbon Permian, Late Triassic, and Middle Jurassic. According to the distribution of coal-bearing rocks, the coalfield can be divided into three coal-bearing belts. (1) East belt. Carboniferous Permian coal production areas include Jungar, Hedong, Weibei, etc. (2) West Belt. Carboniferous-Permian coal production areas are the main ones, including Zhuizi Mountain, Helan Mountain, Weizhou, etc., and there are also sporadic Middle Jurassic coal production areas such as Rujigou. (3) Middle belt. On its east side are Dongsheng and Shenmu coal production areas of the Middle Jurassic and Zichang and Niuwu Late Triassic; on its west side are Lingwu and Guyuan Middle Jurassic coal production areas; in its south are Huangling, Binxian, Longxian and Huating and other Middle Jurassic coal origins.
Geological structure
This coalfield is a nearly north-south structural basin. The syncline axis is on the line between Ningxia Yanchi and Gansu Huanxian, and the east wing is gentle (20℃). The axis is composed of the Cretaceous system, and the Jurassic, Triassic, Permian, Carboniferous and Ordovician systems are distributed sequentially to the two wings. The syncline is covered by the Cenozoic unconformity. The late Paleozoic and Mesozoic strata were formed in a broader sedimentary basin pattern in North China, allowing the coal measures to be preserved. The structural conditions of the entire basin are simple, especially in the east wing with small and medium-sized fold faults. The Carboniferous-Permian coal series include the late Carboniferous Benxi Formation (Yanghugou Formation), Taiyuan Formation, the Early Permian Shanxi Formation and the Lower Shihezi Formation. Group of coal-bearing strata. The coal seam conditions are shown in Table 1.
The Late Triassic coal series is named Wayaobao Formation, which belongs to the top layer of the Yanchang Group of the Upper Triassic. It is composed of continental sandstone, mudstone intercalated with coal seams and oil shale, and is partially intercalated with mudstone lenses. Thick 186-412M. Minable coal seams are only distributed in two coal producing areas, Zichang County and Niuwu, Fuxian County. The number of coal seams can reach up to 32, but most of them are thin coal seams, with only two layers mineable. The total thickness of the mineable coal seams is 0.3 1-4.66M.
The Middle Jurassic coal series, named Yan'an Formation, is composed of continental sandstone, shale, and claystone intercalated with coal seams, and is 60-618M thick. Except for the areas south of the Dali River, north of the Hulu River, and east of Wuqi County in northern Shaanxi, where there are no mineable coal seams in this group, other parts of the coalfield contain mineable coal seams (Table 2)
< p>ResourcesThe coal resources in the entire coalfield are about 1800GT, of which about 650GT are buried shallower than 100M.
As of the end of 1989, the total proven reserves were 346.4GT. The proven reserves of each coal producing area are: Zhungeer 25.3GT, Hedong 50.3GT, Weibei 6.2GT, Dongsheng 73.3GT, Northern Shaanxi 135.7GT, Zi Chang 0.8GT, Huangling 14.4GT, Rujigou 0.6GT, Lingwu 25.4GT, Huating 5.2GT, Zhuizhuishan 3.7GT, Helanshan 2.5GT, Weizhou Hengcheng 3.0GT.
The coalfield is also a large oil and gas-bearing basin. In addition to the Huachi-Huanxian and Yinchuan-Lingwu areas in the central and western regions, many medium and small oil fields have been discovered, as well as many medium and small oil fields in the entire basin. In addition to the distribution of small gas fields, natural gas reserves of 100GM3 have been proven in the Jingbian-Hengshan area in recent years, making it the largest natural gas field on land in China.
Coal quality
(1) Carboniferous Permian coals are mostly medium to ash-rich, low to high sulfur coals. Generally, the Shanxi Formation mainly produces low to medium sulfur coals. The Taiyuan Formation is dominated by high-sulfur coal. Except for the long-flame coal in Zhungeer in the north, the other coal producing areas are all bituminous coal. The coal grades in the east belt increase in degree of metamorphism from north to south on the plane: the northern section of the Hedong coal producing area (Fugu-Lishi) is gas coal, the southern section (Lishi-Xiangning) is fat, coke, and lean coal, and the Wei coal The North Coalfield is thin and poor coal (deep anthracite). The coal in the western belt is mostly gas, fertilizer and coking coal. The Lishi, Liulin and Xiangning areas in the southern section of the Hedong coal producing area are China's main coking coal bases. (2) Late Triassic coal is low-medium ash, medium sulfur coal, and is gas coal. (3) The Middle Jurassic coals are medium-low ash and low sulfur coals. Except for Rujigou which is anthracite coal and Huangling which has some gas coal, the others are non-caking coal, weak caking coal or long-flame coal. Dongsheng and northern Shaanxi areas in the northern part of the coalfield have extremely low ash content and are famous for producing high-quality thermal coal in China; Rujigou has also become a famous producing area for high-quality anthracite coal due to its extremely low ash content.
Mining conditions
The geological structure and hydrogeological conditions in most areas of the coalfield are very simple, and they are among the best coal mining conditions in China. However, the small and medium-sized faults in the coal producing areas of Weibei, Helan Mountain and Zhuizhuishan are more complicated. The mid-deep part of Weibei (below elevation +380M) is also threatened by Ordovician limestone water. In the shallow part of the coal seam, the dip angle of the coal seam is gentle, which is suitable for the construction of open pit mines (Zungar, Dongsheng, Shaanbei, Huangling, etc.). The existing mining mines are still shallow, and most of them are low-gas mines. Gas outbursts are only found in the Shizuishan mining area. Since coal seam methane increases with depth, it is estimated that the risk of gas outbursts will increase in the future. Coal dust explosions have occurred in Weibei, Helan Mountain, Hedong and other places. Spontaneous ignition is common in Middle Jurassic coal seams; Carboniferous-Permian coal seams, except for the Helanshan mining area, generally do not ignite naturally.
Development Overview
Since the Song Dynasty, coal mining activities have been carried out in Weibei, Hedong, Helan Mountain and other places. Relics of coal mining dating back to the Warring States Period have also been found in Weibei. At present, nine mining bureaus have been established in the coalfield, with an annual coal output of more than 30MT, including coal mines of various operating systems and sizes. In recent years, the annual coal output has reached nearly 100MT. As China's coal industry strategy moves westward, this coalfield has become the focus of national coal industry construction. There are still large-scale coal bases under construction: Zhungeer (open-air), Liliu, Dongsheng, Shenmu and Huating. Huainan Coalheld (Huainan Coalheld): Carboniferous-Permian coalfield on the south side of the coal-rich area in North China. It is located in the north-central part of Anhui Province, with Huainan City as its main body. It extends into Chuxian area in the east and near Fuyang in the west. It is an oblong oval in the northwest direction, with a length of about 100km, a width of 20-30km, and an area of ??2500km. The coalfield spans both sides of the Huaihe River. Because the discovery and development started from the south bank, it was named Huainan Coalfield. Later, after exploration, coal was found in a larger area on the north bank of the Huaihe River, but the original name was used.
1. Geological structure
The Huainan Coalfield is a complex syncline structure with an axis extending from northwest to northwest. It is mainly composed of the Upper Paleozoic and the Lower Paleozoic is located on the south and north sides of the coalfield. , coalfields are generally covered by the Quaternary System. Low-angle thrust thrust faults develop on the southern and northern edges of the coalfield, causing the Lower Paleozoic to overturn the Upper Paleozoic several times. In the syncline, a group of northeast-trending normal faults developed, cutting the Upper Paleozoic into stepped blocks. Carboniferous-Permian coal measures widely occur in complex synclines and often form secondary folds. The magmatic activity in the Yanshan period mostly invaded the coal series with small aplite, lamprophyre dykes, and bedrock, which had a local impact on the coal seams.
The coal-bearing strata in the Huainan coalfield are North China-type Carboniferous-Permian coal measures, including: the Benxi Formation and Taiyuan Formation of the Late Carboniferous, the Shanxi Formation and the Lower Shihezi Formation of the Early Permian, and the Late Permian The most stone box set in the world.
The main coal-bearing strata are the Upper Shihezi Formation, Lower Shihezi Formation and Shanxi Formation of the Permian. The Carboniferous strata basically contain no mineable coal seams.
Benxi Formation: It is composed of shallow marine facies and offshore facies thin limestone and ferro-aluminous claystone, generally 5 to 10m thick.
Taiyuan Formation: It is composed of shallow marine facies intercalated with coastal facies limestone, mudstone, sandstone and thin coal seams. There are 10 to 13 layers of limestone and 8 to 11 layers of thin coal seams, of which 1 to 2 layers are partially mineable. Generally, the thickness of the whole set is 100~120m.
Shanxi Formation: composed of coastal facies sandstone, mudstone and coal seams, generally 60 to 70m thick, containing 1 to 3 coal seams, with a total coal seam thickness of about 7m.
Xiashihezi Formation: composed of continental mudstone, siltstone, sandstone, oolitic mudstone and coal seams, 100-150m thick. There are 13 to 16 coal seams, most of which are mineable, with a total coal seam thickness of 18.73m.
Shangshihezi Formation: composed of continental sandstone and mudstone, the middle and lower rocks are gray in color, and contain coal seams with a total thickness of 13.09 meters; the upper rocks are red, green, yellow and other variegated tones, containing thin coal seams 3 ~5 layers, all cannot be mined. The whole group is 600~800 meters thick.
2. Resources
The Huainan Coalfield has about 66% coal resources, about 15% proven coal reserves, and the basic burial depth of unproven coal seams exceeds 1,000 meters. The old mining area south of the Huaihe River, Produces 1/3 of coking coal and a very small amount of gas coal; the Panji mining area north of the Huaihe River mainly produces gas coal; the ash content in the coal is medium to high, and the sulfur content is generally low, making it a good coal for coking. Refractory clay minerals also occur in the coal measures, and reserves have been identified in the Xiejiaji-Xinzhuang area. 6 The deep gas content in the old Huainan mining area is relatively high, which effectively improves the prospects for drainage and utilization.
3. Mining geological conditions
The Huainan coalfield is dominated by medium-thick inclined coal seams with moderate structural complexity, and general mining conditions are acceptable. The Quaternary loose layer is 0 to 800 meters thick and thickens from east to south. It contains gravel and quicksand layers, and a special drilling method is required for well construction. Mine water filling is mainly caused by atmospheric precipitation and the infiltration of Quaternary sand layer water. The hydrogeological conditions are relatively simple, but the Taiyuan Formation limestone karst water is more complicated. It is inverted in the stratum or connected by faults, which has an impact on the mining of Permian coal seams. . Urumqi Coalfield: An important Jurassic coalfield in northern Youzhou, China. It is located in the southern Junggar Basin of Xinjiang and is in the shape of a long strip, about 400km long from east to west. Urumqi City is located in the east of the middle of the coalfield. It is divided into five coal producing areas, from east to west: Shuixigou, Shekang, Urumqi, Manas, and Sisumu. The Urumqi coal producing area in the eastern part of the coalfield is the current main production mining area.
1. Geological structure
The coalfield is located in the Junggar and Cenozoic Basin with south-west linear flexure and fold development. The fold axis tilts south-southeast, the local strata are upright or inverted, and the medium and small fault structures are medium to simple. The coal series belongs to the Middle and Lower Jurassic, and the lower part is the Badaowan Formation of the Early Jurassic. It is composed of continental sandstone and mudstone intercalated with coal seams. It is about 1000m thick and contains 10 to 19 layers of coal seams. The average total thickness of the recoverable coal seams is 10.70 to 16.41m; the middle part is the Early Jurassic Sangonghe Formation, which is mainly composed of continental sandstone and siltstone. It only contains coal locally and is generally of no mining value. It is about 500m thick; the upper part is the Middle Jurassic Xishanyao Formation, which is composed of sandstone and mudstone. It is composed of continental rock groups intercalated with coal seams, containing 28 to 39 coal seams, with an average total minable coal seam thickness of 97.88 to 134.70m. Coal seams are mostly medium-thick to thick, but 1 to 3 extra-thick coal seams generally develop, with thicknesses up to 30 to 50m. The coal seams are most developed in the Urumqi coal producing area, and the coal content gradually becomes worse as it extends to the east and west sides.
2. Coal resources
The coal resources are about 100Gt, and the proven coal reserves are about 4Gt. Most coal types are long-flame coal, some are weakly caking coal or non-caking coal, and some have a small amount of gas coal. The coal is generally low ash and low sulfur, and a few are medium ash. It is a relatively excellent fuel coal. On the south side of the coalfield, there are 5 to 23 layers of oil shale in the Late Permian Lucaogou Formation with a total thickness of 34 to 66m, which has development and utilization prospects.
3. Mining conditions
The coalfield is rich in coal resources, with a coal density of up to 60Mt/km2. The geographical location is relatively advantageous. Although the coal seams are mostly steeply inclined to inclined coal seams, the thickness of the coal seams It is large, the structure is relatively simple, the roof is relatively stable, the development conditions are very good, and the shallow parts of some sections can still be open-pit mined. Most mine water is filled with fissures and is mainly supplied by surface water along the direction of the coal seam. The hydrogeological conditions are simple.
The gas content in mines is not high and they are generally low-gas mines. Coal dust has a certain risk of explosion, and coal dust explosions have occurred in Jiudaowan Mine. The phenomenon of natural coal ignition is common, and fire zones basically exist in the shallow parts of existing production wells.
4. Development overview
The coal produced in the Urumqi coalfield is basically supplied. The land or adjacent areas have a relatively low level of development. The main area in the area is the Urumqi Municipal Affairs Bureau, which has five coal mines under its jurisdiction, with an annual output of about 2Mt. The annual production capacity of local and township coal mines at the end of 1985 was 3.54Mt.