(A) the physical properties of coal
The physical properties of coal are the external manifestations of some chemical compositions and molecular structures of coal. It is determined by original coal-forming materials and their accumulation conditions, transformation process, coalification degree, wind and oxidation degree. Including color, luster, pink, specific gravity and bulk density, hardness, brittleness, fracture and conductivity. Among them, except for specific gravity and conductivity, which need to be measured in the laboratory, everything else can be determined by naked eye observation. The physical properties of coal can be used as the basis for preliminary evaluation of coal quality, and can be used to study the genesis and metamorphic mechanism of coal and solve geological problems such as coal seam correlation.
1. color
Refers to the natural color of fresh coal surface, which is the result of coal absorbing light waves of different wavelengths. It is brownish black and generally deepens with the increase of coalification degree.
glitter
Refers to the reflection ability of the surface of coal under ordinary light. Generally asphalt, glass and diamond luster. The higher the degree of coalification, the stronger the luster; The more mineral content, the deeper the luster; The deeper the wind and oxidation, the darker the luster until it disappears completely.
3. Pink
It refers to the color of grinding coal into powder or the traces left by coal carving on glazed porcelain plates, so it is also called stripe color. Light brown-black. Generally, the higher the degree of coalification, the deeper the pink color.
4. Specific gravity and bulk density
The specific gravity of coal, also known as the density of coal, is the ratio of the weight of a certain volume of coal after removing pores to the weight of water at the same temperature and volume. The bulk density of coal is also called the weight or false specific gravity of coal, which is the ratio of the weight of a certain volume of coal including pores to the weight of water at the same temperature and volume. The bulk density of coal is an important index for calculating coal seam reserves. The bulk density of lignite is generally 1.05 ~ 1.2, that of bituminous coal is 1.2 ~ 1.4, and that of anthracite varies greatly between 1.35 ~ 1.8. The composition of coal and rock, the degree of coalification and the composition and content of minerals in coal are the main factors affecting the specific gravity and bulk density. With the same mineral content, the proportion of coal increases with the deepening of coalification.
5. Difficulties
Refers to the ability of coal to resist external mechanical action. According to the different ways of mechanical external force, the hardness of coal can be further divided into three categories: scoring hardness, indentation hardness and wear resistance hardness. The hardness of coal is related to the degree of coalification, and the hardness of lignite and coking coal is the smallest, about 2 ~ 2.5; The hardness of anthracite is the largest, close to 4.
6.brittleness
Is the extent to which coal is destroyed by external forces. The original coal-forming materials, coal composition and coalification degree all have effects on the brittleness of coal. Among the coals with different metamorphic degrees, the brittleness of long-flame coal and gas coal is smaller, the brittleness of fat coal, coking coal and lean coal is the largest, and the brittleness of anthracite coal is the smallest.
7. rupture
Refers to the cross-sectional shape formed after coal is hit by external force. Common cracks in coal are shell-shaped cracks and serrated cracks. The original material composition and coalification degree of coal are different, and the fracture shape is also different.
8. Electrical conductivity
Refers to the ability of coal to conduct current, usually expressed in resistivity. Lignite has low resistivity. When lignite is transformed into bituminous coal, the resistivity increases sharply. Bituminous coal is a poor conductor, with the increase of coalification degree, the resistivity decreases, and it drops sharply when it comes to anthracite, so it has good conductivity.
(2) Chemical composition of coal
The chemical composition of coal is very complex, but it can be divided into two categories: organic matter and inorganic matter, with organic matter as the main component.
The organic matter in coal is mainly composed of five elements: carbon, hydrogen, oxygen, nitrogen and organic sulfur. Among them, carbon, hydrogen and oxygen account for more than 95% of organic matter. In addition, there are very small amounts of phosphorus and other elements. The elemental composition of organic matter in coal changes regularly with the change of coalification degree. Generally speaking, the deeper the coalification, the higher the carbon content, the lower the hydrogen and oxygen content and the lower the nitrogen content. The content of sulfur is only related to the genetic type of coal. Carbon and hydrogen are important elements that generate heat when coal is burned, and oxygen is a combustion-supporting element, which constitutes the main body of organic matter. When coal is burned, nitrogen does not generate heat, and often precipitates in a free state. However, at high temperature, some nitrogen is converted into ammonia and other nitrogen-containing compounds, which can be recycled to produce ammonium sulfate, urea and nitrogen fertilizer. Sulfur, phosphorus, fluorine, chlorine and arsenic are harmful elements in coal. Sulfur-rich coal combustion produces sulfide gas, which not only corrodes metal equipment and reacts with water in the air to form acid rain, pollutes the environment and harms factory production, but also when coal containing sulfur and phosphorus is used for metallurgical coking, most of the sulfur and phosphorus in the coal are converted into coke during smelting and then into steel, which seriously affects the quality of coke and steel and is not conducive to steel casting and processing. When burning or coking coal containing fluorine and chlorine, all kinds of pipes and furnace walls will be strongly corroded. If arsenic-containing coal is used as fuel in brewing and food industry, high arsenic content will increase the toxicity of products and endanger people's health.
Inorganic substances in coal are mainly water and minerals, and their existence reduces the quality and utilization value of coal, most of which are harmful components in coal.
In addition, there are some rare, dispersed and radioactive elements, such as germanium, gallium, indium, thorium, vanadium, titanium and uranium, which exist in coal in the form of organic or inorganic compounds respectively. Some of these elements are important mineral resources once they reach industrial level or can be comprehensively utilized.
The chemical composition and content of coal can be known through elemental analysis, and the properties of coal can be preliminarily understood through industrial analysis, and the types and uses of coal can be roughly judged. The industrial analysis of coal includes the determination of moisture, ash and volatile matter and the calculation of fixed carbon.
1. moisture
Refers to the water content per unit weight of coal. There are three existing states of water in coal: external water, internal water and crystal water. Generally, the internal moisture of coal is used as an index to evaluate coal quality. The lower the degree of coalification, the greater the internal surface area of coal and the higher the moisture content. Moisture is harmful to the processing and utilization of coal. During coal storage, it can accelerate weathering, cracking and even spontaneous combustion; In the process of transportation, it will increase the volume, waste the capacity and increase the freight; When coking, it consumes heat, reduces the furnace temperature, prolongs the coking time and reduces the production efficiency; When burning, reduce the effective calorific value; In winter in alpine regions, coal will freeze, making loading and unloading difficult. Only when briquettes and briquettes are pressed, a proper amount of water is needed to form them.
Step 2: Grey
Refers to the solid residue left by coal after complete combustion under specific conditions. It comes from the oxidative decomposition of minerals in coal. Ash is extremely unfavorable to the processing and utilization of coal. The higher the ash content, the lower the thermal efficiency; When burning, molten ash will also form slag in the furnace, which will affect the gasification and combustion of coal and make it difficult to discharge slag. When coking, all coke is transferred, which reduces the strength of coke and seriously affects the quality of coke. The composition of coal ash is very complex, and different components directly affect the melting point of ash. Coal with low ash melting point will bring many difficulties to production operation when it is burned and gasified. Therefore, when evaluating the industrial use of coal, it is necessary to analyze the ash composition and determine the melting point of ash.
3. Volatiles
Refers to the combustible gas produced by thermal decomposition of organic matter in coal. It is the main index to classify coal and is used to preliminarily determine the processing and utilization properties of coal. The yield of volatile matter in coal is closely related to the degree of coalification. The lower the coalification degree, the higher the volatile matter, and the lower the volatile matter gradually.
4. Fixed carbon
When determining the volatilization of coal, the remaining nonvolatile matter is called coke residue. Coke residue minus ash is called fixed carbon. It is a non-volatile solid combustible in coal and can be calculated by calculation method. The appearance of coke residue is closely related to the properties of organic matter in coal. Therefore, according to the appearance characteristics of coke residue, the caking property and industrial use of coal can be qualitatively judged.
(3) Technical characteristics of coal
In order to improve the comprehensive utilization value of coal, it is necessary to understand and study the technological properties of coal to meet the requirements of various aspects of coal quality. The technological properties of coal mainly include: cohesiveness and coking, calorific value, chemical reactivity, thermal stability, light transmittance, mechanical strength and washability.
1. Cohesion and coking
Cohesiveness refers to the property that coal particles can be bonded to each other in the process of dry distillation due to the decomposition and melting of organic matter in coal. Coking refers to the ability of coal to form coke during dry distillation. The caking property of coal is a necessary condition for coking. Coal with good caking property must have good caking property, but coal with good caking property may not be able to produce coke with good quality alone. This is why coking needs coal blending. Cohesion is the main index of coal industrial classification, which is generally expressed by the thickness of colloid formed by thermal decomposition and softening of organic matter in coal, and is often called the thickness of colloid layer. The thicker the colloidal layer, the better the cohesiveness. There are many methods to determine adhesion and coking, except for the determination of colloidal layer, Logar index method, Oya expansion test and so on. Cohesion is affected by many factors, such as coalification degree, coal composition, oxidation degree, mineral content and so on. The coals with the highest and lowest coalification degree are generally not caking, and the thickness of colloidal layer is also very small.
2. calorific value
Refers to the heat generated by the complete combustion of coal per unit weight, also known as calorific value, usually expressed as 106J/kg. It is an important index to evaluate coal quality, especially thermal coal. In the international market, thermal coal is priced according to its calorific value. Since1June 1985, the reform in China has followed the pricing method from ash to calorific value for decades. The calorific value is mainly related to the content of combustible elements in coal and the degree of coalification. In order to compare coal consumption, in industrial production, the actual coal consumption is often converted into standard coal with calorific value of 2.930368× 107J/kg for calculation.
3. Chemical reactivity
Also known as activities. Refers to the ability of coal to interact with carbon dioxide, oxygen and water vapor at a certain temperature. It is an important index to evaluate gasified coal and thermal coal. Reactivity directly affects coal consumption and effective components of gas. The activity of coal generally decreases with the deepening of coalification.
4. Heat resistance
Also known as heat resistance. Refers to the ability of coal to maintain its original particle size at high temperature. This is another important index to evaluate gasified coal and thermal coal. Thermal stability directly affects the normal production in the furnace and the gasification and combustion efficiency of coal.
5. Light transmittance
Refers to coal with low coalification degree (lignite, long flame coal, etc.). ). After being treated with a mixed solution of nitric acid and phosphoric acid under specific conditions, the light transmittance of the obtained solution is called light transmittance. With the deepening of coalification, the light transmittance increases gradually. Therefore, it is an important index to distinguish lignite, long flame coal and gas coal.
6. Mechanical strength
Refers to the difficulty of lump coal being broken by external force. When coal with low mechanical strength is put into gasifier, it is easy to break into small pieces and powder, which affects the normal operation of gasifier. Therefore, coal used for gasification must have high mechanical strength.
7. Optional
It refers to the difficulty of removing dirt bands and minerals from coal by washing. See Section 4 for the current coal preparation methods in China.
Second, the use and technical and economic indicators
(A) the industrial classification of coal
From 65438 to 0958, the state promulgated a classification scheme based on coking coal, which created favorable conditions for the rational utilization of coal resources by industrial departments, but there were also some problems in practice. On the basis of careful analysis and absorption of foreign advanced classification methods, in order to make the technical and economic indicators of each classification best reflect the quality characteristics of coal and achieve the purpose of more rational utilization of coal resources, the state re-promulgated the comprehensive technical classification standard from lignite to anthracite in 1986, and divided the coal in nature into 14 categories, in which lignite and anthracite are divided into 2 and 3 categories respectively (Table 2. This is the current national standard for coal classification in China.
Table 2.2. 1 China National Coal Classification Standard (GB575 1-86)
(1) classification index and its symbol Vr are dry ash-free volatiles (%); Hr is dry ash-free hydrogen content (%); GR.I (abbreviated as G) is the caking index of bituminous coal; Y is the maximum thickness of bituminous coal colloid layer; PM is the light transmittance of coal sample (%); B is Australasian expansion degree of bituminous coal (%); Q-A.GNGW is the higher calorific value (MJ/kg) of constant humidity and ash-free base coal.
(2) Coding of coal All kinds of coal are represented by two Arabic numerals. 10 indicates the volatile matter of coal, and the unit number indicates the coalification degree of anthracite and lignite, and the caking property of bituminous coal.
(2) Main characteristics and uses of various coals
1. lignite
It is the lowest coalified coal. It is characterized by high water content, low specific gravity, high volatile matter, non-bonding, strong chemical reactivity, poor thermal stability, low calorific value and containing different amounts of humic acid. It is often used as fuel, raw material for gasification or low-temperature dry distillation, and can also be used to extract montan wax and humic acid to make sulfonated coal or activated carbon. 1 lignite can also be used as organic fertilizer for farmland and orchard.
2. Long flame coal
The volatile content is high, and there is no or only a small amount of cohesiveness. The thickness of the colloidal layer is less than 5mm, which is easy to burn and has a long flame when burning, so it is named long-flame coal. It can be used as raw materials for gasification and low-temperature dry distillation, and can also be used as civil and power fuel.
3. Non-stick coal
High water content, non-caking, basically no colloid when heated, low calorific value when burned, and contains certain secondary humic acid. Mainly used for making gas and civil or power fuel.
4. Weak cohesive coal
High water content, weak cohesiveness and high volatile matter. When heated, less colloid and coke can be produced independently, but the formed coke block is small and brittle, and the coke powder rate is high. This kind of coal is mainly used as gasification raw material and power fuel.
5. Cohesive coal in1/2
Medium cohesiveness and high volatile matter. It can be used as raw material for coal blending and coking, as well as gasification coal and power fuel.
6.bituminous coal
High volatile matter, thick colloidal layer and poor thermal stability. Coke can be formed independently, but the refined coke is slender and fragile, with large shrinkage, many longitudinal cracks and poor crushing resistance and wear resistance. Therefore, it can only be used for coal blending and coking, and can also be used for oil refining, gas production, nitrogen fertilizer production or power fuel.
7. Gas-fat coal
Its volatile matter and caking property are high, and its coking property is between gas coal and fat coal. When coking alone, a large number of gas and liquid chemicals can be produced. It is most suitable for high-temperature dry distillation to make gas, and is also a good raw material for coking with coal blending.
8. Fat coal
Good adhesion, high volatile matter. When heated, it can produce a large amount of colloid, forming a colloid layer larger than 25mm, which has the strongest coking property. Coking with this kind of coal can produce coke with good melting and wear resistance, but this kind of coke has many transverse cracks, and the root of coke is often honeycomb-shaped and fragile into small pieces. Because of its strong cohesiveness, it is the main component of coking with coal blending.
9. 1/3 coking coal
It is a transitional coal between coking coal, fat coal and gas coal. Strong adhesion, medium and high volatile matter. When coking alone, coke with good meltability and high strength can be formed. Therefore, it is a good basic coal for coking with coal blending.
10. Coking coal
It has low volatile matter and high cohesiveness, and can form colloid with good stability when heated. When used alone in coking, coke with compact structure, large volume, high strength, good wear resistance, few cracks and not easy to break can be formed. However, due to its high expansion pressure, it is easy to push coke and damage the furnace body, so it is generally used for coking and coal blending.
1 1. Lean coal
It has low volatile matter and medium cohesiveness. Coke with large size, few cracks, good crushing strength and poor wear resistance can be formed when coking alone. Therefore, adding it to coking coal blending can increase the fragmentation and strength of coke.
12. Lean coal
Low volatile matter, weak cohesiveness and poor coking. When coking alone, a large amount of coke powder will be produced. But it can be used as a diluent. Therefore, it can be used for coking and coal blending, and it is also a good fuel for civil use and power.
13. Lean coal
There is a certain volatile matter, which does not produce colloid when heated, has no cohesiveness or only weak cohesiveness, has short combustion flame and does not coke when coking. Mainly used for electricity and civil fuel. In areas lacking poor materials, it can also be used as a diluent for coking with coal blending.
anthracite coal
It is the highest coalification coal. Low volatile matter, high specific gravity, high hardness, less smoke when burning, short flame and strong firepower. Usually used as civil and power fuel. High-quality anthracite can be used as gasification raw material, fuel for injecting and sintering iron ore in blast furnace, and manufacturing calcium carbide, electrodes and carbon materials.
(3) Quality requirements of industrial coal
Coal has a wide range of industrial uses, which can be summarized as metallurgy, chemical industry and electric power. At the same time, it also has broad application prospects in oil refining, medicine, precision casting, aerospace and other fields. All industrial sectors have specific quality requirements and technical standards for the coal used. A brief introduction is as follows:
1. Coking coal
Coking is to add hot coal to the retort. With the increase of temperature (eventually reaching about 65438 0000℃), the organic matter in coal gradually decomposes. Among them, volatile substances escape in gas or vapor state and become coal gas and coal tar, and the remaining non-volatile products are coke. Coke plays an important role in reducing and melting ore, providing heat energy, supporting burden and maintaining good permeability of burden in ironmaking blast furnace. Therefore, the quality requirements of coking coal aim at obtaining high-quality metallurgical coke with high mechanical strength, uniform briquetting and low ash and sulfur content. The state has special quality standards for metallurgical coking coal, as shown in Table 2.2.2.
Table 2.2.2 See the above figure for the quality standard of metallurgical coking coal (GB397-65).
2 coal for gasification
Coal gasification takes oxygen, water, carbon dioxide, hydrogen, etc. as gas media, and through thermochemical treatment, coal is converted into various gases. The gas products obtained from coal gasification can be used as industrial and civil fuels and raw materials for chemical synthesis. There are two common methods of gas production: ① fixed bed gasification. At present, China mainly uses anthracite and coke as gasification raw materials to produce synthetic ammonia feed gas. It is required that the fixed carbon, ash (Ag) and sulfur content (SGQ) of coal used as raw materials should be > 80%, ≤ 2%, with uniform particle size of 25 ~ 75 mm, or 19 ~ 50 mm, or 13 ~ 25~75mm, and the mechanical strength should be > 65%. The quality requirements for raw coal are: chemical reactivity should be greater than 60%, non-binding or weakly binding, ash (Ag) < 25%, sulfur (SGQ) < 2%, moisture (WQ) < 10%, ash melting point (T2) > 1 200℃, and particle size < 60.
3. Coal for oil refining
Generally, lignite and long-flame coal are mainly used, and weakly caking coal and gas coal are also acceptable, depending on the refining method. ① Low-temperature dry distillation method, that is, dry distillation of coal at about 550℃ to produce low-temperature tar, and at the same time, semi-coke and low-temperature coke oven gas can be obtained. There are lignite, long flame coal, non-sticky coal or weakly sticky coal and gas coal. The quality requirements for raw coal are: tar yield (TF) > 7%, colloidal layer thickness < < 9mm, thermal stability S+ 13 > 40%, particle size 6 ~ 13mm, preferably 20 ~ 80mm. (2) Hydroliquefaction, that is, mixing coal, catalyst and heavy oil, destroying the organic matter in coal at high temperature and high pressure, reacting with hydrogen and converting it into low molecular liquid or gaseous products, and further processing to obtain gasoline, diesel and other fuels. Raw coal is mainly lignite, long flame coal and gas coal. It is required that the carbon hydrogenation (C/H) of coal is <16, the volatile matter is > 35%, the ash (Ag) is < 5%, and the carbon content of coal and rock filaments is < 2%.
4. Coal as fuel
Any kind of coal can be used as fuel for industry and civil use. Different industrial sectors have different quality requirements for fuel coal. The requirements for coal used for steam locomotives are relatively high. The national regulations are: volatile matter (Vr)≥20%, ash (Ag)≤24%, ash melting point (T2)≥ 1 200℃, sulfur (SgQ) ≤ 1%, and low calorific value ≤ 2.09365438+. General power plants try to use inferior coal with ash content (Ag) > 30%, and a few large boilers can use coal with ash content (Ag) of about 20%. In order to use high-quality coal to develop metallurgical and chemical industries, China has made rapid progress in the application of low calorific value coal in recent years. Many inferior coals and coal gangue with calorific value of only about 8 372.5J/ kg can also be used in general factories, and some power plants are mixed with 30% coal gangue.
Coal has many other uses. For example, lignite and oxidized coal can produce humic acid fertilizer; Montan wax can be extracted from lignite and used in power supply, printing, precision casting, chemical industry and other departments. High-quality anthracite can be used to make silicon carbide, carbon sand, artificial corundum, artificial graphite, electrode and calcium carbide, and can be injected into blast furnace or used as casting fuel. Carbon fiber made of coal tar pitch has tensile strength thousands of times higher than that of steel, light weight and high temperature resistance, and is an important material for developing aerospace technology. Coal tar pitch can also be made into needle coke to produce new electric furnace electrodes, which can improve the production efficiency of electric furnace steelmaking and so on. In short, with the continuous progress of modern science and technology, the comprehensive utilization technology of coal is also developing rapidly, and the comprehensive utilization field of coal will continue to expand.
Third, a brief history of mining industry
(A) a brief history of ancient coal mining industry
China is the first country to discover and utilize coal in the world. From 65438 to 0973, a large number of clean coal products were found in the lower floor of Xinle site in Neolithic age near Beiling, Shenyang, Liaoning Province. Among them, there are 25 round bubble ornaments, 6 earrings and 0/5 round beads/kloc. At the same time, 97 pieces of pulverized coal, semi-finished products of clean coal and coal blocks were unearthed. These coal products, identified by the Scientific Research Institute of the former Liaoning Coalfield Geological Exploration Company, are characterized by "weak oily luster, uniform structure, high hardness and good toughness", which are easily ignited with matches, giving off a bright smoky flame and emitting the smell of burning rubber. Industrial analysis and elemental analysis prove that the raw material is candle coal. This is the conclusive evidence of the earliest use of coal in the world, and it is also the historical witness that China discovered and began to use coal as early as six or seven thousand years ago.
In the mid-1950s and mid-1970s, archaeologists successively unearthed coal carvings in four Western Zhou tombs in Shaanxi Province, among which more than 200 pieces were unearthed in Rujiazhuang, Baoji City. According to this, it can be judged that as early as the Western Zhou Dynasty, as the political and economic center of the country at that time, coal had been developed and utilized.
During the Warring States period, in addition to carving daily necessities with coal, there were also records about coal in the works at that time. There are three records about stone nirvana in Shan Hai Jing, a geographical work in the pre-Qin period: one is in Xishan Jing, a mountain with a woman's bed, whose yang is full of copper and its yin is full of stone nirvana; In the other two places, we can see "The head of Minshan Mountain, named Daughter Mountain, is covered with stony pine" and "Traveling 150 miles eastward, it is called Fengyu Mountain, covered with platinum and covered with stony pine". According to relevant experts' research, Nvchuang Mountain, Nver Mountain and Fengyu Mountain are located in Fengxiang, Shuangliu, Shifang, Tongjiang, Nanjiang, Bazhong and other places in Sichuan. Compared with ancient times and modern times, there are coal outputs in the above places, which proves that the records in Shan Hai Jing are basically correct. At the same time, it shows that coal has been discovered in these places at that time, and some preliminary geological knowledge of coal prospecting has been accumulated.
From the Western Han Dynasty to the Wei, Jin, Southern and Northern Dynasties, a certain scale of coal mines and corresponding coal mining technologies appeared. Coal is not only used to produce fuel, but also used to make iron. Not only raw coal can be used, but also pulverized coal can be molded into briquette, which improves the utilization value of coal. The origin of coal is not only in the north, but also in the south and even Xinjiang. At the same time, at this time, coal carving technology has been initially popularized.
From Sui and Tang Dynasties to Yuan Dynasty, coal was developed and used more widely. Metallurgy, ceramics and other industries all use coal as fuel, and coal has become the main commodity in the market, and its position is becoming more and more important, and people's understanding of coal has deepened. In particular, coking with coal began to sprout in the Tang Dynasty, and by the Song Dynasty, the coking technology had reached maturity. 1in the autumn of 978 and1in the winter of 979, Shanxi Institute of Archaeology excavated a large amount of coke in the brick tomb of the Jin Dynasty in Macun, Jishan County, Shanxi Province. 1957 winter solstice to April 0958, the cultural relics team of Hebei Provincial Cultural Bureau excavated three coke oven sites in Yantai Town, Fengfeng mining area, Hebei Province. The appearance of coke and the invention of coking technology indicate that the processing and utilization of coal has entered a brand-new stage.
During the twenty years from Ming Dynasty to Daoguang in Qing Dynasty (1840), the feudal rulers at that time paid more attention to the development of coal, took some measures to develop coal production, and the mining management policies also changed, and the coal industry developed greatly in all aspects. Coal development technology has been developed, forming a rich and colorful ancient coal science and technology in China. Although they were all manually operated coal mines at that time, they were mined and utilized earlier than other countries. Therefore, before17th century, China was in a leading position in many aspects of coal technology and management, which is worthy of our pride. However, the declining feudal system finally hindered the development of ancient coal industry and led to the birth of modern coal mines in China.
(B) a brief history of modern coal mining industry
1840 after the opium war, China was forced to open its doors and enter a semi-feudal and semi-colonial society. Modern shipping industry and machinery industry began to appear, which needed a lot of coal, but the old manual coal kiln production was far from meeting the needs. Therefore, the Qing Westernization School actively brewed the introduction of western advanced coal mining technology and equipment, so modern coal mines began to appear. The main signs of modern coal mines are: first, the capitalist management model; Second, steam-driven hoists, ventilators and drainage machines are used in the three production links of lifting, ventilation and drainage, while other production links still rely on manpower and animal power. This technical situation lasted almost until 1949, and even some changes were only partial and minor. This is the main technical feature that distinguishes modern coal mines from ancient manual coal mines and modern mechanized mines.
The earliest modern coal mines in China are Keelung Coal Mine in Taiwan Province Province and Kaiping Coal Mine in Hebei Province. Keelung Coal Mine was set up by British coal engineers hired by Shen Baozhen, Governor of the two rivers of the Qing government. Built in 1876 and 1878, it produces coal, with an annual output of about 30,000 ~ 50,000 t. Due to poor management, the output gradually declined shortly after it was put into production. 1884 during the sino-French war, the mine was bombed and stopped production. Kaiping Coal Mine was built by Li Hongzhang, the governor of Zhili, in 1876. Established in 1877, Tangshan mine was built in 188 1, and later Linxi and Xishan mines were built. To 1894, the average daily output reached 1 500t, the highest daily output. During this period, 14 modern coal mines with different scales and years were successively opened, which were either government-run, jointly run by government and businessmen, or jointly run by government and businessmen, all of which were bureaucratic capitalism. Due to poor management, insufficient funds and small scale, most of them failed.
After the Sino-Japanese War of 1894, 1894, China's national strength declined, and the foreign powers took advantage of it one after another, and a large number of foreign capitals invaded and occupied China coal mines. 1In April, 898, the Jiaoao Lease Treaty signed by China and Germany stipulated: "Germany will build two railways from Jiaozhou Bay, Shandong Province, and German businessmen have the right to mine minerals within 30 miles (15km) on each side of the railway." Since then, Britain, Russia, France and Japan have successively seized similar rights. According to incomplete statistics, during the period of 1895 ~ 19 12, there were 42 treaties, agreements and contracts (including other mineral deposits) that imperialists seized China's coal mine rights, involving Liaoning, Kyrgyzstan, Heilongjiang, Yunnan, Guangxi, Sichuan, Anhui, Fujian, Guizhou, Shandong and Anhui. Kaiping, Luanzhou, Jiaozuo, Mengxian, Pingding (now Pingding County), Lu 'an, Zezhou, Pingyang, Benxi Lake, Lincheng and other large coal mines have been opened one after another. The output of foreign coal mines accounted for 83.2% of the total output of modern coal mines in China at that time, which basically controlled the coal industry in China. The imperialist aggression aroused the resistance of the people of China. From 1903, the campaign to recover mining rights was launched, which reached its climax at 19 1 1. The patriotic gentry and businessmen in China were dissatisfied with the outflow of profits, and raised funds to start many coal mines in the people's campaign to recover mining rights. Bureaucratic comprador saw that it was profitable to open coal mines, did not want to miss the opportunity, and tried their best to open coal mines. Thus, from 1895 to 1936, modern coal mines in China show a development trend.
1937 After the July 7th Incident, Japanese imperialists occupied most of the coal mines in China, including foreign-funded coal mines, and their mining methods were completely predatory. From 193 1 to 1945, the Japanese occupied more than 200 coal mines in China, plundered 420 million tons of coal and destroyed countless coal resources.
During the War of Resistance against Japanese Aggression period, the National Government Resources Committee directly managed 29 coal mines and encouraged private enterprises to set up 59 coal mines with an annual output of about 6 million tons. In the liberated areas, some small coal mines were also opened for local soldiers and civilians to use as fuel. According to post-war statistics, there are 473 small coal mines in the Shanxi-Chahar-Hebei border region with a daily output of 2,739 tons.
1945 after War of Resistance against Japanese Aggression's victory, a small number of Japanese-occupied coal mines were taken over by the People's Government of the Liberated Areas, and most of them were taken over by the Kuomintang regime. At the beginning of the war of liberation, affected by the changeable political and military situation, some coal mines changed hands several times and were in a state of suspension or semi-suspension. After 1947, the national government gradually disintegrated. It was not until 1949 that the new China was born that these coal mines returned to the hands of the people's government, but they were seriously damaged.
(3) A brief history of modern coal mining industry
According to incomplete statistics, when New China was founded, the local people's government took over about 40 coal mining enterprises, 200 mines and a few open-pit mines in old China. Mainly distributed in Northeast China, North China, East China's Shandong, Anhui and other provinces. Except for a few places, they are small in scale, poor in equipment and backward in technology. Coupled with the destruction of long-term war, they are riddled with holes and a scene of decline and ruin. For example, 9 pairs of mines in Datong Coal Mine, Shanxi Province were all flooded, and all machinery and equipment were destroyed. There is no intact working face underground, no complete workshop on the ground, no machine can operate normally, no roadway can be opened to traffic normally, and production stops completely. The west open pit mine and Longfeng mine in Fushun coal mine in Liaoning province have been flooded and basically stopped production; 1 1 of the 18 pithead in Jiaozuo Coal Mine, Henan Province was completely destroyed, and only the derrick was left in 7 pitheads, which have completely stopped using. Zibo, Zaozhuang, Yangquan and other large coal mines are also in ruins. The coal mining industry in New China started from such a mess.