Coal is one of the most important fossil fuel materials today because it generates more than 40% of all electrical energy on the planet. This is thanks to its great energy power and its relatively easy extraction. In this article you will learn all the important information about this organic sedimentary rock, its characteristics and uses.
What is mineral coal?
Mineral coal is actually considered in geology as a sedimentary rock that has organic origin, that is, it has been formed by the lithification of plant remains in swampy environments, therefore, it is rich in carbon.
Although there are many varieties of coal, the term mineral coal generally refers to compact rock capable of being used as a fossil fuel, for example, anthracite and bituminous coal.
Is coal renewable or non-renewable?
We already know that this rock is formed mainly by the accumulation and lithification of organic remains of plants. However, its formation process is not overnight, for mineral coal to form it takes millions of years.
Taking into account that there is currently a very accelerated exploitation of this natural resource, it is practically impossible for the natural process of coal formation ore exceeds its production.
Therefore, like all fossil fuels this rock is considered as a non-renewable source or resource, since it is a limited resource on the planet.
Characteristics of mineral coal
Chemical composition
The following table shows the chemical composition of this rock, note that the anthracite and bituminous coal varieties that correspond to the mineral carbon As such, they exceed 75% in carbon content and have a high calorific value, which is why it is used as an important fuel.
| Coal | Carbon (%) | Humidity (%) | Heat (MJ/kg) |
| Anthracite | 86-92 | 7-10 | 32-33 |
| bituminous coal | 76-86 | 8-18 | 23-33 |
| sub bituminous coal | 70-76 | 18-38 | 18-23 |
| Lignite | 65-70 | 35-55 | 17-18 |
| Peat | 60 | 75 | fifteen |
Mineral composition
Regarding its mineral composition, this sedimentary rock is very complex because, due to its origin, it can generate many types of minerals, but they only occupy less than 8% of the total volume.
For example, it is common to find clay minerals such as kaolinite, illite, montmorillonite, and chlorite. It may also contain hydrocarbons, silica (SiO2), graphite, pyrite, calcite, siderite, feldspars, galena, chromite, gypsum, etc.
Color
The mineral carbon it usually has dark, black and dark brown hues. The black hues are due to the content of graphite and organic material, while the brown hues are due to the amounts of siderite, feldspars and some other carbons.
Structure and texture
This type of rock can have in its structure the vestiges of the organic remains that formed it, that is, you could see shapes of leaves, roots, or any remains of plants and stems. In general, these textures and structures appear as horizontal layers according to the accumulation of organic remains.
Importance of coal
The importance of coal It lies in the fact that it can currently be used as a fossil fuel with high energy power, in fact, it is capable of supplying at least 40% of the world’s electricity.
The electricity it produces is widely used in the industrial sector and the oil sector. Thus, its high carbon and hydrocarbon content releases energy through combustion. You can learn all the advantages and disadvantages of this rock by following this link.
Origin, formation and deposits of mineral coal
Let us remember that the mineral coal in geology It is considered as a fossil fuel and a non-renewable resource because its distribution is limited in the crust. Now we will know what were the formation conditions and their deposits.
The largest amount of coal on the planet will eventually formed about 300 million of years in a period known as Carboniferous on the geological scale.
At this stage the planet was covered by extensive but shallow seas that flooded extensive areas of forests and jungles. Shallow water created swampy environments on continents trapping large amounts of plants, mosses, leaves, plant debris, and algae in those swamps
With it these organic remains are buried and are covered by other sediments and more organic remains, as this happens they are subjected to greater pressure and temperature, and above all the mud and acid water prevent these plant remains from coming into contact with oxygen.
This causes the materials to decompose very slowly, and then, due to diagenesis and lithification processes, coal is formed as organic sedimentary rock, and this also explains its high carbon content.
Currently the largest coal reserves are in the United States, Russia, China, Australia and India.
How is mineral coal extracted?
According to its origin and formation, mineral coal appears in the crust as horizontal and sometimes slightly inclined vents that can be a few meters thick, even up to 30 meters, and can extend for several kilometers.
These conditions make its exploitation feasible through open pit and underground mines where miners carefully separate the mineral coal from the bedrock.
Advantageously the coal appears very close to the surface and it is possible to carry out this combined mining exploitation.
Uses of mineral coal
In electricity generation
The main application that has mineral carbon It is in the generation of electricity. This rock is considered a fossil fuel with a high calorific and energetic value. When burned they generate a lot of heat, this heat is used to boil water and generate steam, then this steam drives large special turbines that generate electricity.
In steel production
The mineral carbon it is an excellent source of carbon and other chemical elements such as chromium. These chemical elements are essential for the production of steel, which is a combination of iron plus carbon and other elements.
In the chemical and pharmaceutical industry
The mineral carbon it is an excellent source of carbon, hydrocarbons, tar and other minerals that are used to produce oils, phenols, benzenes and naphthalenes. Also many of the by-products of coal are used to make soaps, dyes, plastics, chemical solvents and much more.
To make fertilizer
In this case, mineral coal is used to produce hydrogen by combustion, then this hydrogen is mixed with ammonia to create fertilizers used in agriculture.