The main coal seam in Henan is No.2 coal seam 1, that is, No.2 coal seam 1. Specifically, thank you.

I. Coal-forming Plant

Second, the formation of coal.

Three. Necessary conditions for coal formation

I. Coal-forming Plant

Coal formed by lower plants is called sapropelic coal.

The coal formed by higher plants is called humus coal.

Second, the formation of coal.

The whole process from the accumulation of plant residues to the transformation into coal is called coalification. This process has experienced complex biochemical and physical and chemical effects.

Coal formation is divided into two stages:

(1) Peat (sapropelic) stage

Plants reproduce, die and accumulate, and are constantly decomposed, combined and accumulated under the action of microorganisms. Higher plants form peat, while lower plants form sapropel.

1. Salinization

(1) Concept-The biochemical process in which lower plants and plankton become sapropelic in reducing environments such as lakes, lagoons and bays is called sapropelic.

(2) sapropelic mud-dark gray, dark brown gelatinous turbid substance containing a lot of water.

2. Peatization

(1) Concept-The process that the remains of higher plants become peat through complex biochemical and physicochemical reactions in peat bogs is called peatization. It is divided into two stages:

① The first stage: the plant residues are oxidized and decomposed in the shallow part of the swamp.

② The second stage: With the increase of water depth, the oxidation environment is replaced by the reduction environment, which produces humic acid and asphaltene and forms peat.

(2) Peat is yellowish brown, dark brown, dull and loose in texture, which can be used as fuel, chemical raw materials and fertilizer after air drying.

(2) coalification stage

After the formation of peat or sapropelic mud, it is covered by other sediments due to the decline of the earth's crust and enters the coalification stage. At this time, the biochemical action stops and is replaced by physical and chemical action. Includes two consecutive processes:

1. Diagenetic peat (sapropelic coal) becomes lignite (sapropelic coal) after compaction, dehydration and solid transfer under the action of temperature and pressure.

2. Metamorphic lignite is continuously transformed into bituminous coal, anthracite, natural coke or graphite under the influence of temperature, pressure and time.

Three. Necessary conditions for coal formation

(A) the material basis of coal formation under plant conditions

(2) Climatic conditions affect the growth and decomposition of plants, and warmth and humidity are important climatic conditions.

(3) Geographical conditions for the accumulation of plant remains.

(4) Condition balance of crustal movement Crustal settlement (the settlement speed is balanced with the accumulation speed of plants)

Material Composition, Properties and Classification of Section II Coal

Main contents:

I. Composition of coal and rock and macroscopic types of coal and rock

Second, the nature of coal

Third, the classification of coal

I. Composition of coal and rock and macroscopic types of coal and rock

(1) coal and rock composition

The composition of coal and rock refers to the basic unit of coal that can be seen by naked eyes, also known as macroscopic coal and rock types, namely silk coal, vitrinite coal, dark coal and bright coal.

1. Silk charcoal

Gray-black, shaped like charcoal, with obvious fiber structure and silky luster;

Loose, porous, low hardness, high brittleness, easy to hurt fingers;

Non-caking, strong oxygen absorption, easy oxidation and spontaneous combustion, easy to form coal dust;

There are many flat lenses with a thickness of several millimeters in the coal seam, but they are widely distributed.

2. Mirror coal

Black, bright as a mirror, developed endogenous cracks, uniform structure, fragility and strong adhesion;

No independent bedding is formed in the coal seam, and it is dispersed in bright coal in a lenticular or strip shape;

3. Bright coal

Gray-black, strong luster, brittle and brittle, endogenous cracks developed, and the uniformity is not as good as vitrinite;

The chemical process properties are between vitrinite and dark coal, and the ash content is low;

It accounts for a large proportion in coal seam, and can form thick layer or separation layer.

4. Dark coal

Gray-black, dull, dense and hard, with great toughness;

Unclear bedding, high mineral content and complex composition have great influence on coal quality;

It accounts for a large proportion in coal seam, and can form thick layer or separation layer.

(2) Macro coal and rock types

According to the average luster intensity of coal seam and the combination of coal and rock components, coal can be divided into four types: bright, semi-bright, semi-dark and dim.

1. Bright briquette is mainly composed of vitrinite and bright coal, with strong luster and brittle fracture development. Medium metamorphic bright briquette is the best coal for coking.

2. Semi-bright briquette is mainly bright coal, and its luster strength is not as good as that of bright briquette. Generally, the light and dark stripes are interlaced to present a semi-bright average luster, which is the most common.

3. Semi-dark briquette is composed of dark coal and bright coal, mainly dark coal, with dark luster, high hardness, great brittleness and undeveloped endogenous cracks.

4. Dull briquette is composed of dark coal, sometimes sandwiched with vitrinite and silk charcoal, with dull luster, inconspicuous bedding, strong hardness and toughness, and poor coal quality.

Note: In practical work, only coals with the same metamorphic degree can be compared and classified into different types, and the minimum thickness of classification is generally 3 ~ 10 cm.

Second, the nature of coal

(A) the chemical composition of coal

Coal is a mixture of organic matter and inorganic matter, in which organic matter is the main component, mainly C, H, O (accounting for more than 95%), and N, S, etc.

1. carbon (c) is the main component of coal. The more carbon, the higher the calorific value of coal, and the more carbon content in coal, which increases with the deepening of metamorphism.

2. Hydrogen (H) is an important component in coal, and its calorific value is 4.2 times that of C. Lower plants are rich in H, so the H content of sapropelic coal is higher than that of humus coal. H in coal decreases with the deepening of metamorphism, and H content in gas coal is the highest in bituminous coal series.

3. The oxygen in oxygen (O) coal decreases with the deepening of metamorphism, but it changes greatly. From lignite, long flame coal, gas coal to fat coal, the decline is significant; From coking coal, lean coal, lean coal to anthracite, the decline is small.

4. The content of nitrogen (N) is less, and it tends to decrease slightly with the deepening of metamorphism. It can be converted into ammonia (NH3) and other nitrogen compounds at high temperature.

5. Sulfur is one of the harmful elements in coal. Sulfur in coal is divided into inorganic sulfur and organic sulfur (So), and inorganic sulfur is divided into sulfide sulfur (pyrite sulfur, Sp) and sulfate sulfur (gypsum sulfur, Ss). Organic sulfur mainly comes from coal-forming plants. The sum of sulfur in coal is called total sulfur (St), and coal is divided into six grades according to the total sulfur content of St and D (%) on a dry basis:

grade

Ultra-low sulfur coal

Low sulfur coal

Low sulfur and medium sulfur coal

Medium sulfur coal

Medium-high sulfur coal

high-sulphur coal

Saint de

≤0.50

0.5 1~ 1.00

1.0 1~ 1.50

1.5 1~2.00

2.0 1~3.00

& gt3.00

6. Phosphorus (P) mainly exists in inorganic minerals, and its content is extremely low and harmful. When phosphorus enters coke, steel is cold and brittle, so the content of P in coking coal is required to be below 0.02% ~ 0.03%.

7. Other elements in coal include harmful elements such As arsenic (As) and chlorine (Cl), and beneficial elements such as germanium (Ge), gallium (Ga), uranium (U), lithium (Li) and vanadium (V).

(2) Physical properties of coal

1. Colors and stripes

Color refers to the natural color of the surface of fresh coal. It changes with the increase of metamorphic degree: generally, it ranges from lignite, bituminous coal to anthracite, and its color ranges from brown, brownish black and dark black to grayish black and cyan gray.

Stripe refers to the color of pulverized coal, which is not much different from the color.

glitter

Refers to the reflection ability of fresh coal surface, and the luster increases with the increase of coal metamorphism. Vitrinite and bright coal have great changes in coal and rock composition, so they are taken as observation objects.

3. Density

Refers to the mass of coal per unit volume (g/cm3)

Deterioration degree of influence factor (1): The higher, the greater the density.

(2) Coal and rock composition: dark coal is the largest, bright coal is the second, and vitrinite is the second.

Classification: (1) true density: the mass of coal per unit volume (excluding pores) at 20℃, which was once called true specific gravity.

(2) Apparent density: the mass per unit volume (including pores) of coal at 20℃, which was once called bulk density or weight. The real density is very small.

(3) Relative density: the ratio of coal density to water density at the same temperature. It is also divided into true relative density (true specific gravity) and apparent relative density (false specific gravity).

4. Hardness and brittleness

Hardness: the ability to resist external mechanical action, Mohs hardness is between 1~4. The hardness of lignite and coke is small, and anthracite is the largest; Dark coal with the same metamorphic degree is harder than bright coal and vitrinite coal.

Brittleness: the difficulty of sudden fracture under the action of external force. The brittleness of low and high metamorphic coal is small, while that of medium metamorphic coal is large. Among the coal and rock components, silk charcoal is the largest, vitrinite is the second, and dark coal is the smallest.

break

Refers to the cracking phenomenon caused by various natural forces during the formation of coal. According to the reasons, it can be divided into two categories:

(1) Endogenous fracture: It is formed by volume shrinkage under the influence of temperature and pressure during coalification. The fault plane is flat and perpendicular to the bedding plane, and there are often two groups perpendicular to each other, one is dense and the other is sparse, and the middle metamorphic coal is the most developed.

(2) Exogenous cracks: geological structure changes after the formation of coal seams. Cracks are widely spaced and can appear in any part of the coal seam. They often cross multiple coal strata and cross bedding planes, and their directions are generally consistent with those of nearby faults.

6. Conductivity

Refers to the ability of coal to conduct current, expressed by resistivity, which is closely related to the metamorphic degree of coal. Lignite is porous, with high humidity and low resistivity; Bituminous coal is a poor conductor because of its high resistivity; Anthracite has low resistivity and good conductivity.

(3) Common indexes for evaluating coal quality

Coal has a wide range of industrial uses, but the requirements for coal quality are different. Therefore, the analysis of technological properties of coal is an important means to evaluate coal quality. The commonly used indexes for evaluating coal quality are:

1. Industrial analysis index of coal

1) moisture (m) is divided into two categories according to the combined state:

(1) bound water (crystal water) is water bound with mineral components in coal.

(2) Free moisture is divided into two categories, and the sum of the two categories is also called total moisture (Mt):

(1) External moisture-water adsorbed on the surface of coal and large capillaries on the surface, which is easy to evaporate;

(2) Internal moisture-water absorbed by small capillaries in coal will not be lost when heated to a certain extent at room temperature.

Lost the temperature.

2) Ash (a) Residue left after coal is completely burned, the main components are Al2O3, CaO, SiO2, etc. They come from minerals in coal and are divided into six grades according to ash content:

grade

Extremely low

Ash coal

Low ash content

Separated coal

Low grade

Ash coal

slaked lime

Separated coal

highest

Ash coal

High ash content

Separated coal

Advertising (%)

≤5.00

5.0 1~

10.00

10.0 1~20.00

20.0 1~30.00

30.0 1~40.00

40.0 1~50.00

3) volatility (v)

The coal separated from the air is heated to Tmin at the temperature of (900 10℃), and the organic matter and some minerals are decomposed, and the gaseous substances obtained are called volatiles.

Volatile matter is related to the nature and metamorphic degree of organic matter in coal.

70% peat, 40-60% lignite, 10-50% bituminous coal and less than 10% anthracite.

4) Determination of volatile matter of fixed carbon (FC) The residual coke residue minus ash is fixed carbon. It is the residue of pyrolysis of organic matter in coal.

2. Technical characteristics of coal

Different industrial coals have different requirements for process performance.

1) caking refers to coal powder particles (diameter

(1) Cohesion index (g) 1g Coal sample was evenly mixed with 5g standard anthracite (Rujigou, Ningxia), and the obtained coke was quickly heated under the condition of being isolated from air, so as to determine the wear resistance index of coke, that is, the g value reflecting the ability of coal sample colloid to bond inert substances. The greater the G, the stronger the cohesion.

(2) Maximum thickness of colloidal layer (y) Put the coal sample into a colloidal layer tester that simulates the coking industrial conditions, and measure the thickness of its colloidal layer regularly to find its maximum value. The larger y is, the stronger the cohesiveness is.

(3) Austenite-sub-expansion degree (b) The expansion degree of coal measured by heating with expansion tube can reflect both the quantity and quality of bituminous coal colloid and fully reflect the caking property of bituminous coal. The greater the B, the stronger the coking property of coal.

2) calorific value (q) refers to the calorific value generated by the complete combustion of coal per unit mass, expressed in megajoules per kilogram (MJ/Kg).

Before coking coal, the calorific value increased with the deepening of metamorphism, and after coking coal, the calorific value decreased slightly. Coal is divided into six grades according to calorific value.

grade

low

Coal with high calorific value

Middle and low grade

Coal with high calorific value

middle

Coal with high calorific value

highest

Coal with high calorific value

high

Coal with high calorific value

superhigh

Coal with high calorific value

QMJ/ kg

8.50~

12.50

12.5 1~

17.00

17.0 1~2 1.00

2 1.0 1~24.00

24.0 1~27.00

& gt27.00

Third, the classification of coal

(a) according to the degree of coal coalification and process performance classification

1. The classification index is:

① Vdaf (dry ashless volatile matter)

② GR-I (bituminous coal caking index)

③ Y (maximum thickness of bituminous coal colloid layer)

④ b (Aubrey-Subexpansion Degree of Bituminous Coal)

⑤ Hdaf (dry ash-free hydrogen content)

⑥ PM (light transmittance of coal sample)

⑦ Qgr.maf (constant humidity ash-free base coal has higher calorific value)

Among them, dry ash-free base refers to coal completely free of moisture and ash (excluding combustible materials).

2. Classification principle

① Distinguish anthracite, bituminous coal and lignite by coalification parameter Vdaf;

② Vdaf and Hdaf are used to distinguish the subcategories of anthracite;

③ use Vdaf, g, y and b to distinguish bituminous coal types;

④ Distinguish lignite from bituminous coal by visual colorimetry transmittance PM, and classify lignite into subcategories;

⑤ Qgr.maf is an auxiliary index to distinguish lignite from bituminous coal.

3. According to the national standard of China coalfield classification1986./kloc-0.1,it is divided into 14 categories and 29 subcategories.

Among them, 14 is:

Anthracite gas fertilizer coal

Bonded coal in lean coal

Lean coal? Medium caking coal

Lean bituminous coal and weak cohesive coal

Coking coal unbonded coal

1/3 coking coal long flame coal

Fat coal lignite

(2) Classification by comprehensive utilization of coal

1. Coking coal: isolated from air in the retort, heated to about 1000℃, and decomposed to produce coke oven gas, coal tar and coke.

2. Coal for gasification: coal is converted into gas by thermochemical treatment using CO2, H, O, H2O and other media.

3. Low-temperature dry distillation of coal: dry distillation at 500-600℃ to produce low-temperature tar, gas, etc.

4. Hydroliquefaction of coal: mixing coal, catalyst and heavy oil, reacting with hydrogen at high temperature and high pressure, transforming into liquid and gaseous substances, and then further processing to obtain gasoline and diesel oil.

5. Coal for combustion: the utilization value is the lowest, so inferior coal is used.

The third coal measures and coalfields

Main contents:

I. Coal measures and their types

Second, the composition of coal measures

Three, coal field, coal accumulation period, coal accumulation area

I. Coal measures and their types

(A) the concept of coal measures

Refers to a set of coal-bearing rock series formed in a certain geological period with genetic connection and continuous deposition.

1, the strata system must contain coal seams;

2. It is mainly composed of sedimentary rocks, and may contain volcanic rocks and pyroclastic rocks in areas with strong crustal movement;

It contains a lot of plant fossils.

(2) Type of coal measures

Coal measures are formed in the process of crustal oscillation dominated by subsidence movement. Because of the different nature and amplitude of oscillation, as well as the differences in geographical environment and scope, the characteristics of coal measures are also different.

1, offshore coal measures;

Coal measures are usually coastal plains or coastal lagoons, bays and shallow seas. Due to the small-scale oscillation of the earth's crust, it is sometimes submerged by seawater intrusion, or shallow sea, and sometimes becomes land, and swamps are widely developed.

Main features:

1) is widely distributed;

2) Lithology and rock relative ratio;

3) There are more sign layers;

4) The circulation structure is very clear;

5) relatively easy;

6) The thickness of coal seam is relatively stable, but most of them are thin-medium thick coal seams;

7) The sulfur content of coal seam is generally high.

8) contains a large number of plant fossils and marine animal fossils;

Such as: Carboniferous coal measures in North China; Permian coal measures in southern China

2. Inland briquette series

The deposits of this coal series are all located on land, such as inland basins, intermontane basins and piedmont basins. No seawater intrusion occurred during the deposition process, and the coal measures were all composed of continental sediments.

Main features:

1) the thickness of coal measures is generally large, the distribution area is generally small, the lithology and lithofacies change greatly, and the coal seams are not easy to compare;

2) The thickness of coal seam is large, there are many layers, the thickness changes greatly, and bifurcation and pinch-out occur from time to time;

3) The coal measures have complex structure and low sulfur content;

4) The composition of coal-bearing rock series is complex, rich in a large number of plant fossils and freshwater animal fossils;

5) In some places with strong crustal movement, volcanic rocks and pyroclastic rocks can appear in coal measures strata;

Second, the composition of coal measures

(1) coal seam

1. Structure of coal seam

The coal seam contains coal stratification and rock interlayer, and the one without rock interlayer is called simple structure coal seam; On the contrary, the coal seam with stone layer is called complex structural coal seam.

The material source of coal gangue mainly depends on the sedimentary environment of peat swamp.

Coal seam structure has certain influence on coal mining method, selection of mining machinery and raw coal quality. When the coal seam contains thick gangue, it can be mined separately. When the structure of coal seam is complex and it is difficult to separate mining, stone inclusions will be mixed in coal, which will reduce the quality of raw coal.

Therefore, in the stage of coalfield geological exploration, the coal seam structure should be found out and the quality of raw coal should be preliminarily evaluated.

2. Coal seam thickness-the vertical distance between the top and bottom strata of coal seam.

Total thickness: it is the sum of the thickness of each coal seam and rock stratum between the top and bottom of coal seam;

Favorable thickness: refers to the total thickness of each coal seam between the top and bottom of coal seam;

Mineable thickness: refers to the thickness of coal seam suitable for mining under modern economic and technical conditions.

Minimum minable thickness: the lower limit standard of minable thickness stipulated according to the current national technical policy and the coal type, occurrence, mining method and resource conditions in different regions. (Influencing factors: coal type, occurrence, mining method and resource conditions)

3. Classification of coal seam thickness

Divided by thickness

0.3-0.5m ultra-thin coal seam

0.5- 1.3m thin coal seam

1.3-3.5m medium-thick coal seam

3.5-8.0m thick coal seam

& gt8m thick coal seam

Divided by inclination angle

& lt5 near horizontal coal seam

5-25 gently inclined coal seam

25-45 inclined coal seam

& gt25 Steep Coal Seam

Stable coal seam: general >: recoverable thickness, and the change of coal seam thickness has certain regularity;

Relatively stable coal seam: the thickness of coal varies greatly, most of which are recoverable and some are not;

Unstable coal seam: the coal thickness changes greatly, and bifurcation, pinch-out, thickening and thinning occur from time to time;

Extremely unstable coal seam: often lenticular, distributed intermittently, only partially recoverable.

According to stability

Coal seam thickness and its change is one of the main geological factors affecting coal mining. Coal mining methods are different with different coal seam thicknesses.

The change of coal seam thickness, such as bifurcation, thinning and pinch-out, will directly affect the balance of coal reserves and the normal production of coal mines.

(2) Coal seam roof and floor

1. The roof is located at a certain distance above the coal seam. There are three types of roofs:

1) false roof: the thin rock layer directly covering the coal seam, mostly carbonaceous shale and mudstone, is generally several centimeters to dozens of centimeters thick and is easy to collapse.

2) The direct roof is located on the false roof, mostly siltstone and mudstone, with a thickness of about 1-2m, which can collapse by itself after prop-pulling.

3) The main roof is located on the direct roof, mostly sandstone and limestone, with large thickness and high strength. After coal mining, it is not easy to collapse on its own for a long time, and only subsidence occurs.

2. The floor is located at a certain distance below the coal seam. There are two kinds:

1) Direct floor: The rock stratum directly below the coal seam is mostly carbonaceous mudstone, often tens of centimeters thick.

2) The old floor is located under the direct floor, mostly siltstone and sandstone, with a large thickness.

(3) coal measures marker layer

Some strata in coal measures with special lithology, easy identification, stable horizon or obvious distribution law can be used as marker beds for finding and comparing coal seams.

For example: limestone, conglomerate, bauxite, sandstone with special lithology and color, etc.

Three, coal field, coal accumulation period, coal accumulation area

(1) Coalfield and coal-producing area

1. Coal seam refers to the distribution area of coal-bearing series formed in the same geological period and roughly continuously developed. The area generally ranges from tens to hundreds of square meters. Such as Shandong Luxi coalfield and Liaoning Fuxin coalfield.

2. Coal-producing areas refer to some separate coal-bearing rock series distribution areas separated by late structural changes and denudation. Generally, it can correspond to mines or mining areas. Such as Yangquan mining area in Shanxi and Yanzhou mining area in Shandong.

(2) The main coal accumulation period in China.

Coal-accumulating period, also known as coal-forming period, refers to the geological period in which coalfield resources were formed in geological history.

There are seven most important coal accumulation periods in China:

1. Early Carboniferous 5. Early and Middle Jurassic

2. Carboniferous and Permian. Late Jurassic-early Cretaceous

3. Late Permian. Paleogene and Neogene

4. Late Triassic

(3) Coal-accumulating areas in China.

Taking the large-scale geological structural belt as the boundary, five coal-accumulating areas are divided:

1. Northeast coal-accumulating area: including eastern Inner Mongolia, Heilongjiang, most of Jilin and northern Liaoning. The main coal-forming period is J3 -K 1, followed by Paleogene. The coal resources in this area account for about 8% of the whole country.

2. Northwest coal-rich areas: including Xinjiang, most of Gansu, Ningxia and parts of Inner Mongolia. The main coal-forming periods are C period and J 1-2 period. J 1-2 coal is the strongest, and Xinjiang has the best coal content. The resources in this area are huge, accounting for about 33% of the country.

3. Coal-rich areas in North China: including Shanxi, Henan and Shandong, as well as Shaanxi, Gansu, Ningxia, Inner Mongolia, Liaoning, Kyrgyzstan, Hebei, northern Jiangsu and northern Anhui. The main coal-forming period is C-P, followed by J 1-2 and Paleogene. In particular, C-P coalfields are the most widely distributed and have the largest reserves, accounting for more than 80% of the reserves in this area. The coal resources in this area account for about 53% of the whole country.

4. Yunnan-Tibet coal-accumulating areas: including Tibet, southern Qinghai, western Sichuan and western Yunnan. Mainly P and Neogene coal, C 1, T3 and K2 have poor coal-bearing properties. There are few coal resources, accounting for about 0. 1% of the whole country.

5. Coal-rich areas in South China: including Guangxi, Guizhou, Guangdong, Hunan, Jiangxi, Zhejiang, Fujian, Qionglai, Yunnan, Hubei, Sichuan and other provinces. There are several coal-forming periods: C 1, P2, P3, T3, J 1, N (Neogene), in which the coal-forming effect is strongest from the late P2 to P3. The coal resources in the whole region account for about 6% of the whole country.

Distribution characteristics of coal resources in China: the northwest and north regions are rich in reserves, while the exploration degree in the west region is low and the structure is relatively complex. The eastern coastal economically developed areas have relatively few reserves, but the exploitation period is long, the intensity is high, and the shallow resources are seriously insufficient, so it is difficult to expand to the deep.