Coal is either mined or dug out from coal mines. It is mainly composed of an element, i.e. carbon. Depending upon the percentage of carbon, the three main types of coal are bituminous, the lignite and the anthracite.

 

 

 

 

1. Bituminous

 

2. Lignite

 

 

 

3. Anthracite

 

 

 

 

 

Lignite and bituminous have a low percentage of carbon. They burn faster and release a great amount of pollutants into the atmosphere. Anthracite contains about 98% carbon. It burns slowly and gives much less smoke. Coal of all types also contains small amount of Sulphur. Sulphur is worst of the pollutants and causes damage to human health and to vegetation.