Lignite

Lignite, often called brown coal, is a soft sedimentary rock. It is brown in color and combustible. The rock is created from naturally compressed peat. It has a carbon content around 25–35%. It is thought to be the lowest rank of coal. This is because of its low heat content. Lignite has a  high amount of moisture when it is taken from the ground. This can explain its low carbon content. The rock is mined all around the world. It is mostly used as a fuel for steam-electric power generation.

The combustion of lignite makes less heat for the amount of carbon dioxide and sulfur that come out than other types of coal. Because of this, environmentalists have said that lignite is the worst coal for human health. Many different toxic heavy metals can also be in lignite. These are left over in the coal fly ash made from its combustion. This causes more health risks.

 Uses 

Most lignite is used to make electricity. It is also used in agriculture, in industry, and, as jet, in jewelry.

 References 

 Other websites 


 Geography in action – an Irish case study 
 Photograph of lignite 
 Coldry:Lignite Dewatering Process

Category:Sedimentary rocks