How does coal form?

A fossil fuel, coal is made of vegetation that was compressed between other rock strata and changed over millions of years by the combined effects of pressure and heat to form coal seams. The energy that coal provides us with today was once absorbed by plants from the sun millions of years ago.

kinds of coal

Mineral rocks, which are composed of inorganic material, are very different from coal. Before it becomes the well-known black and shiny substance used as fuel, coal, which is made of delicate plant matter, goes through several changes.

Over millions of years, coal goes through various stages of carbonization, and it can be found in all stages of development in various regions of the world.

According to how much it has changed over time, coal is ranked. According to Hilt's Law, a coal seam's rank increases with depth. More plant debris is converted to carbon as a result of the material being exposed to higher temperatures and pressure at greater depths.

Peat: Peat is not coal, but under the right conditions, it has the potential to become coal in the future. Peat is a buildup of partially decomposed plant material that has undergone minimal carbonization.

Peat, however, is still regarded as a member of the coal "family" because it contains the same energy that coal's original plants did. Additionally, it has a lot of volatile substances and gases, like methane and mercury, which are harmful to the environment when burned.

Peat retains sufficient moisture to be pliable. It can take up water, causing the bog to grow and produce more peat. As a result, it serves as an effective environmental defense against flooding.

. To help the soil hold onto water and nutrients and release them gradually, peat can also be incorporated into the soil. Peat and so-called "peat moss" are useful to gardeners because of this.

In many nations, including Ireland, Scotland, and Finland, peat is a significant source of energy where it is dried and burned for heat.


Lignite: The lowest grade of coal is lignite. It no longer qualifies as peat due to its high carbon content, which ranges from 25 to 35 percent. About 250 million years old, the coal deposits from which it is derived are relatively new.

In comparison to other types of coal, lignite, a crumbly brown rock also known as brown coal or rosebud coal, retains more moisture. Because of this, mining, storing, and transporting it is costly and risky. It can accidentally burn, and when it does, it emits a lot of carbon dioxide. Near the mines where it was extracted, the majority of lignite coal is used in power plants.

Electricity is primarily produced by burning lignite. 25 to 50 percent of the electricity produced by coal in Germany and Greece comes from lignite. Lignin deposits in the United States primarily produce electricity in North Dakota and Texas.


Bituminous Coal

Bituminous coal is formed under more heat and pressure and is 100 million to 300 million years old. It is named after the sticky, tar-like substance called bitumen which is also found in petroleum. It contains about 45-86% carbon.


Coal is a sedimentary rock, and bituminous coal frequently contains “bands,” or strips, of different consistency that mark the layers of plant material that were compressed.



Smithing coal, cannel coal, and coking coal are the three main categories of bituminous coal. Smithing coal is perfect for forges, where metals are heated and shaped because it has a very low ash content.

In the 19th century, cannel coal was widely used as a source of coal oil. The process of pyrolysis, which involves heating cannel coal with a controlled amount of oxygen, produces coal oil. The main source of energy for streetlights and other types of lighting was coal oil. The 20th century saw a decline in the use of coal oil due to the widespread use of kerosene.



Large-scale industrial processes use coking coal. Coking is the process of heating the rock without oxygen to produce coal. This lowers the moisture content and increases the product's stability. Coking coal is necessary for the steel industry.


Nearly half of all the coal used for energy in the United States is bituminous coal. Kentucky, Pennsylvania, and West Virginia are the main mining regions for it. Outside of the United States, countries like Russia and Colombia use bituminous coal as an energy source and industrial fuel.





The highest rank of coal is anthracite. It contains the most energy because it contains the most carbon (up to 97% of its weight). In comparison to other types of coal, it is tougher, denser, and more lustrous. It does not contain the soft or fibrous sections present in bituminous coal or lignite, and nearly all of the water and carbon dioxide have been expelled.


Anthracite burns cleanly with very little soot because it is high-quality coal. Because it is more expensive than other types of coal, power plants rarely use it. Anthracite is instead primarily utilized in furnaces and stoves.

 Water filtration systems also employ anthracite. More dangerous particles are trapped because their pores are smaller than those of sand. As a result, drinking, sanitary, and industrial uses of water are made safer.


Anthracite is typically found in regions that have experienced particularly demanding geologic activity. For instance, the Allegheny Plateau in Kentucky and West Virginia contains coal deposits that reach as far as the Appalachian Mountains' foothills. Temperatures and pressures were high enough to produce anthracite in this location thanks to the orogeny, or mountain formation, process.



Nearly three-quarters of the world's anthracite coal production is mined in China, which dominates the industry. Russia, Ukraine, Vietnam, and the United States are some additional nations that mine anthracite (mostly Pennsylvania).

Graphite : 

The only component of graphite is carbon atoms, making it a carbon allotrope. (Another allotrope of carbon is diamond.) The carbonization process ends with the production of graphite.


Since graphite conducts electricity well, lithium-ion batteries frequently contain it. Additionally, graphite can withstand temperatures of up to 3,000 °Celsius (5,400 °F). It can be found in items like fire-resistant doors and missile components like nose cones. However, pencil "leads" are probably the application of graphite that people are most familiar with. The top three producers of graphite worldwide are China, India, and Brazil.


            The four different types of coal—lignite, sub-bituminous, bituminous, and anthracite—are produced during the "coalification" process.

Coalification refers to the degree of transformation that coal goes through as it develops from peat to anthracite. This is known as the coal's "rank" and has a significant impact on the material's physical and chemical properties. The degree to which the original plant material has been converted into carbon determines the ranking.


  • Each coal deposit's quality is determined by:
  • vegetation types that gave rise to the coal
  • burial depths
  • at those depths, temperatures, and pressures
  • How long has the deposit been producing coal?
  • Coal also includes hydrogen, oxygen, nitrogen, and varying amounts of sulfur in addition to carbon.
  • High-rank coals are low in oxygen and hydrogen but high in carbon, which increases their heat value.
  • Low-rank coals contain little carbon but a lot of hydrogen and oxygen.

Where can I find coal?

There are more than 1.06 trillion tonnes of proven coal reserves in the world, so coal is widely available.

This indicates that there is enough coal to last us for about 132 years at the current rate of production. The United States, Russia, China, Australia, and India have the largest reserves.

The location, scope, and characteristics of the coal resources in the majority of countries are well known after centuries of exploration. The level designated as proved recoverable reserves has a tendency to vary significantly more than the assessed level of the resource, or the amount of potentially accessible coal in the ground.

Through enhanced exploration efforts and improvements in mining techniques, reserves can be extended further, opening up previously inaccessible reserves.


How is coal discovered?

Exploration activities lead to the identification of coal reserves. Typically, the procedure begins with the creation of a geological map of the region, followed by geochemical and geophysical surveys, exploration drilling, and so forth. This makes it possible to create a precise picture of the area. The area will only ever become a mine if it is large enough and of sufficient quality that the coal can be economically recovered. After this is established, mining operations start.

Since there are coal reserves all over the world, there is no single region that produces the most coal. The top five hard coal producers are China, India, the United States, Indonesia, and Australia. The majority of coal is consumed in the nation where it is produced.


utilizes for coal

We all have probably encountered coal at least once in our lives. This substance is widely used in many homes and even large industries. Having said that, we will research coal and some of its applications in this article.

In essence, coal is a combustible sedimentary rock that typically occurs in regions called coal beds or coal seams. It typically takes millions of years to form and is typically black or brownish-black in colour. Geological processes play a major role in the coal formation. It is a kind of fossil fuel that was produced from long-dead plants. It is a nonrenewable energy source, according to classification.

Additionally, the elements carbon, sulfur, hydrogen, and nitrogen are present in coal.

Coal is indirectly used to make steel in the steel industry. Coal is baked in furnaces to create coal coke in this situation. Manufacturers then smelt iron ore into iron and produce steel using coal coke. As for the production of nitric acid, ammonia salts, and fertilizers, ammonia gas is typically recovered from coke ovens.

Industries : 

Industries Coal is used by many industries to make a variety of goods. The cement industry, the paper and aluminum industries, and the chemical and pharmaceutical industries, among others, are some of the well-known industries that use coal. Chemical industries use coal as a source of a variety of raw materials, including benzene, coal tar, sulfate of ammonia, creosote, etc. Most industries rely primarily on coal as a source of energy.

 Gasification and Liquefaction

Coal can be turned into a synthetic gas which is a mixture of carbon monoxide and hydrogen. These gases are intermediate products that can be further converted into different products like urea, methanol, pure hydrogen, and more. Coal can also be turned into a liquid known as synthetic fuels.

However, these chemicals produced from coal are used primarily to make other products. Besides, most of the products out there in the market have coal as components. Some of them include aspirins, solvents, soap, dyes, plastics, and fibers which include nylon and rayon.

Professional Products

Additionally, coal is a crucial component in the manufacture of specialty goods like silicon metals, carbon fiber, and activated carbons.

Household Use

Coal is still used as a heat source and fuel for cooking in cold climates and in developing or underdeveloped nations.

These are some of the main applications of coal. You can download our app for engaging content and learning experiences to learn more about the characteristics and various types of rocks and minerals.


Effects, both positive and negative

In a time when so many activities depend on electricity, coal power plants are essential for producing electricity. However, while mining for the resource degrades the environment, coal power plants significantly contribute to environmental pollution. Water that is used extensively in the processing of coal becomes contaminated with heavy metals and toxic substances like arsenic. Further evidence links the burning of coal to the atmospheric release of greenhouse gases.