What can coal be made to burn, and why can coal be burned?

The main cluster leakage skin with poor coal permeability is composed of carbon, which is an organic substance. Carbon and oxygen are burned at high temperatures to produce carbon dioxide and release energy.

Addendum: Coal has two basic meanings as follows:

1. Ancient plants were buried underground, and under the condition of impermeable air or insufficient air, they were subjected to the deterioration of high temperature and high pressure underground and formed black or black-brown minerals: coal mines, coal fields, coal seams, coal gas, coal tar, and coal essence.

2. The black ash condensed by flue gas is the main raw material for ink making: Souzao coal and loose coal.

The main component of coal is carbon, which is an organic substance. Carbon and oxygen are burned at high temperatures to produce carbon dioxide and release energy.

Addendum: Coal has two basic meanings as follows:

1. Ancient plants were buried underground, and under the impermeable or insufficient air, they were subjected to the underground high temperature and high pressure deterioration and formed black or black-brown minerals: coal mines, coal fields, coal seams, coal gas, coal tar, and coal essence.

2. The black finch condensed by flue gas is good ash, which is the main raw material for ink making: coal and pine coal.

The combustion of coal generally goes through four stages:

1. Water evaporation stage When the temperature reaches about 105, all the water is evaporated;

2. Volatiles ignition stage: After the coal continues to absorb heat, the temperature continues to rise, and the volatiles precipitate out, and when the temperature reaches the ignition point, the volatiles begin to burn. The combustion speed of volatiles is fast, generally only accounting for about 1 10 of the whole combustion time of coal;

3. Coke combustion stage: After the volatiles in the coal are ignited and burned, the remaining solid matter composed of carbon and ash is coke. At this time, the temperature of the coke rises rapidly, and the fixed carbon burns violently, releasing a large amount of heat. The rate of combustion of coal and the degree of ember burning mainly depend on this stage;

4. Ember burning stage: In this stage, the coke in the ash is burned as much as possible to reduce the heat loss of incomplete combustion and improve efficiency.

The correct way to burn coal is as follows: 1. First of all, add some paper to the stove. 2. Put in some dry firewood, preferably in the middle of the dry firewood, and add some plastic confession bags.

3. Then put in the coal, it is the honeycomb coal directly put in, and the coal is broken and put in. 4. After that, put some dry firewood and paper plastic bags in Huaiqian He, and light it. 5. After burning, you can semi-cover the top, it is recommended to use a kettle, so that the lead can be used under the stove.

If you can burn wood in the countryside, it is best to live upstairs with a gas stove, and the wood will become charcoal after a short period of high temperature, and the moisture and impurities contained in it will be removed. Wood smokes because it contains moisture and burns inadequately. Because the water content of the charcoal has been removed, it can fully react with oxygen.

So no smoke. The weight of the wood must become lighter in the process of removing moisture and turning it into charcoal, so it feels like charcoal of the same weight will burn for a long time.

There may be two reasons for my opinion: the calorific value of wood is large, and the rice cooks quickly; Carbon is a more complex mixture, not only carbon, but also sulfur, nitrogen and other substances not only pollute the environment but also burn out the smell of smoke is very pungent, in comparison, wood is a relatively simple mixture, the main elements are carbon, hydrogen.

It is the impurities of the coal, because the coal we burn is not 100% pure, so there must be impurities in the coal. And these impurities are usually carbon, the graphite in the carbon has a metallic luster, and this coal is a coal with a higher coal content, the brighter it is, the higher the purity of the coal. There are also coal minerals, metallic luster may be other minerals, depending on the situation, but most of them are graphite in carbon.

Coal is a combustible black or brownish-black sedimentary rock that usually occurs in rock formations or veins known as coal beds or coal seams. Because later exposed to increased temperatures and pressures, harder forms of coal can be considered metamorphic rocks, such as anthracite. Coal is mainly made up of carbon, along with other elements in varying quantities, mainly hydrogen, sulphur, oxygen and nitrogen.

Historically, coal has been used as an energy resource, primarily for the production of electricity and/or heat, and can also be used for industrial purposes, such as refining metals, or in the production of fertilizers and many chemical products.

High-temperature coking. The high-temperature coking or low-temperature coking mentioned in the circulating fluidized bed boiler refers to the indicated temperature of the instrument (that is, the temperature of the furnace), in fact, whether it is high-temperature coking or low-temperature coking, the temperature of the coking part exceeds the coking temperature of the ash (how high depends on the type of coal).

The reason for over-temperature: the fuel is burned in the combustion chamber to release heat, and the circulating ash enters the combustion chamber by the recycler and mixes with the fuel to absorb the heat and bring the heat out of the combustion chamber, under normal circumstances, the relationship between them is balanced, and the combustion chamber temperature will maintain a fixed value. Only when the heat cannot be brought out in time will the combustion chamber temperature rise.

Furnace temperature can be divided into three cases. (When I say over-temperature, I mean over-temperature coking):

1. The local temperature is too high, and the temperature indicated by the meter is normal. The local material fluidization of the material in the combustion chamber is abnormal, the circulating ash is not mixed well with the fuel or is not mixed, and the heat released by the fuel cannot be taken away in time. The temperature field in the material layer is not uniform (even if the fluidization is normal, the temperature of each point in the material layer is different, but it is closer to the average value, and the temperature indicated by the instrument in daily operation is not completely consistent), and the abnormal part of fluidization is relatively far away from the temperature element, which can not truthfully reflect the actual situation of the local temperature.

None of the temperature indications show overtemperature. The coking at this time is low-temperature coking. Most of the coking in the combustion chamber of the boiler is low-temperature coking, which generally occurs when the furnace is started and stopped, the fire is pressed, the fire is raised, and the quality of low-load coal is poor (referring to the particle size and calorific value of coal).

2. Local over-temperature, the instrument indicates over-temperature. The local material fluidization of the material in the combustion chamber is abnormal, the circulating ash is not mixed well with the fuel or is not mixed, and the heat released by the fuel cannot be taken away in time. The over-temperature or junction focus is just at the temperature measuring element, and the temperature indication can faithfully reflect the actual temperature situation.

This coking rarely occurs independently, as the supervisor does not sit back and wait for the temperature to rise to a specified value. Therefore, this situation is generally caused by the gradual deterioration of coking at low temperatures, and the coke block extends to the vicinity of the temperature measuring element. When the temperature element is surrounded by a coke block, turning on a large air indicates that the temperature drops rapidly or very slowly, and when the small air is turned off, the temperature indicates that the temperature rises rapidly or rises very slowly, and the temperature indication at this point is obviously abnormal compared to other temperature indications, and it may be coking.

The indicated temperature of the meter rarely exceeds the coking temperature.

There are thousands of compounds in it, including small molecule hydrocarbons, aromatics containing benzene rings, macromolecule polyesters, and many others, as well as inorganic small molecules and salts. Their chemical formula cannot yet be expressed.

Some are white, some are yellowish, because mud is added to make honeycomb coal, the main component of coal is carbon, and after combustion, it becomes carbon dioxide (gas), and only mud remains, which is white or yellow.

After charcoal is burned, the remaining solid matter is generally called carbon ash. The ingredients are generally some inorganic salts. It can also be called plant ash. Well, it's mostly potassium carbonate and the like.

A very bright reflective stone was found in the coal, and the family bought coal and found a very bright stone, the upper side was composed of a very tight yellowish crystal, and the lower side was connected to a stone. Very bright and strongly reflective. Put it on an iron plate and burn it in the boiler, that.

A very bright reflective stone was found inside the coal.

The family bought coal and found a very bright stone, the top was composed of a very close yellowish crystal, and the bottom was attached to a stone. Very bright and strongly reflective.

When I put it on the iron plate and burned it in the boiler, the yellowish thing seemed to melt away, and it was still stuck to the iron plate, and I couldn't get it down even if I tried to cut it.

And it's very brittle, please tell me what this thing is.

It is coal gangue that shines, and sulfur that turns yellow.

Ruined ... It's amber or beeswax... A piece is hundreds...

Yellow sulfur iron sulfide.

A very bright reflective stone was found in the coal, and the family bought coal and found a very bright stone, the upper side was composed of a very tight yellowish crystal, and the lower side was connected to a stone. Very bright and strongly reflective. Put it on an iron plate and burn it in the boiler, that.

I picked up a stone that was made up of crystals in it, reflective stones, and it was valuable, but it wasn't what kind of stone it was.

The problem of moonstone identification! I bought a moonstone bracelet the other day with white moonlight and blue moonlight in it. But today I suddenly found out that there are a few stones in it that cannot be reflected from any angle, did I buy a fake?

The clothes are too bright and reflective, how to solve the problem I bought a black coat, and when I came back, it was very bright in the light of the sun, very reflective, which big brother and sister know how to solve it? The inside is down.

The animation of the spaceship is so long, and when I was a kid, it looked like a spaceship powered by a stone, and I may not remember what I found in a little guy's home.

What kind of stone is this? Solution, the appearance is the same as that of ordinary stones, and the inside is very reflective.

Coal is the most abundant and widely distributed fossil fuel on the planet. The main elements that make up the organic matter of coal are carbon, hydrogen, oxygen, nitrogen and sulfur, in addition, there are very small amounts of phosphorus, fluorine, chlorine and arsenic.

Carbon, hydrogen and oxygen are the main bodies of organic matter in coal, accounting for more than 95%; The deeper the degree of coalification, the higher the carbon content and the lower the hydrogen and oxygen content. Carbon and hydrogen are the elements that produce heat during the combustion of coal, and oxygen is the combustion supporting element. When coal is burned, nitrogen does not produce heat and is converted into nitrogen oxides and ammonia at high temperatures, which are precipitated in a free state.

Sulfur, phosphorus, fluorine, chlorine and arsenic are harmful components in coal, with sulfur being the most important. When coal is burned, most of the sulfur is oxidized into sulfur dioxide (SO2), which is emitted with flue gas, polluting the atmosphere, endangering the growth of animals and plants and human health, and corroding metal equipment; When sulfur-rich coal is used for metallurgical coking, it also affects the quality of coke and steel. Therefore, the "sulfur" content is one of the important indicators to evaluate the quality of coal.

The flammable gas produced by the thermal decomposition of organic matter in coal at a certain temperature and under certain conditions is called "volatile matter", which is a mixture of various hydrocarbons, hydrogen, carbon monoxide and other compounds. Volatile matter is also the main coal quality index, and it has an important reference role in determining the processing and utilization methods and process conditions of coal. Coal with a low degree of coalification has more volatile matter.

If the combustion conditions are not appropriate, coal with high volatile content is easy to produce unburned carbon particles when burned, commonly known as "black smoke"; It also produces more pollutants such as carbon monoxide, polycyclic aromatic hydrocarbons, and aldehydes, and reduces thermal efficiency. Therefore, it is necessary to select appropriate combustion conditions and equipment according to the volatile matter of coal.

The content of inorganic substances in coal is very small, mainly water and minerals, and their presence reduces the quality and utilization value of coal. Minerals are the main impurities of coal, such as sulfides, sulfates, carbonates, etc., most of which are harmful components.

"Moisture" has a great impact on the processing and utilization of coal. When the water is burned, it becomes steam to absorb heat, thus reducing the calorific value of the coal. The moisture in coal can be divided into external moisture and internal moisture, and the internal moisture is generally used as an index to evaluate the quality of coal.

The lower the degree of coalification, the larger the internal surface area of the coal and the higher the moisture content.

"Ash" is the solid residue left after the complete combustion of coal, which is an important coal quality indicator. The ash mainly comes from the non-combustible minerals in coal. When the mineral is burned and ashed, it needs to absorb heat, and a large amount of slag discharge needs to take away the heat, so the higher the ash content, the lower the thermal efficiency of coal combustion; The more ash content, the more ash produced by coal combustion and the more fly ash is emitted.

In general, the ash content of high-quality coal and washed coal is relatively low.

Coal has combustible substances in it, such as carbon, and the main component of coal is carbon.

The main component of coal is carbon (c), which is an organic substance.

C+O2 burns > CO2 at high temperatures and releases energy.

After the coal is fractionated, there is coke, coal tar, gas and ammonia in it.

Coke and coal tar account for the majority, and the first three can be burned, and the calorific value of coke is still very high

Coal contains combustible substances.

There are two types of coal combustible substances, one is volatile, which is gaseous combustibles after heating, and the other is fixed carbon.

The main component of coal is carbon.

c + o2 = co2