What is charcoal?

qu'est ce que le charbon ?

There are many coal mines in Belgium. This can be seen in the many slag heaps still present along the motorway which connects Tournai to Liège. This black pebble was in great demand because it was the most important resource people needed to heat themselves in winter or heat the furnaces of factories.

How is coal formed?

Coal is a rock composed mainly of carbon, an element that is found in all living things. It is obtained through the accumulation and sedimentation of plant waste over millions of years. This plant waste is dead leaves, tree branches, or even trees.

Over time, and as a result of gradual changes in temperature and pressure in the soil, this rock will enrich in carbon. This is called the charring.


It is the phenomenon during which the small particles stop moving to deposit in layers, in the bottom.

Anthracite is the most carbon-containing form of coal.

To transform plant debris into anthracite, it takes about 300 to 500 million years. This is why it is also called “fossil resource”.


Why were we using coal?

Coal, when burned, releases a lot of heat. It’s an important source of energy for heating. In the 18th century, Europe experienced the industrial revolution. It was during this time that many companies were born to produce everything that made up people’s daily lives.

To heat the glassmakers’ ovens or to run the steam engines, you had to burn something cheaper than wood. The solution is coal. It is the only fuel capable of producing enough energy to replace wood.

As a result of this, many mines are opened all over Europe to extract the precious ore.

A black pebble as light as a feather.


When we take it in our hands, the coal seems extremely light to us. If we look at the coal with a powerful microscope, we see that it is filled with cavities and craters. A bit like a slice of Swiss cheese. In other words, coal is light because it is full of microscopic holes and filled with air.


It is the transformation of a plant into charcoal under the action of heat.

Map of coal mining areas in Belgium.

Map produced by Hans Erren.