Lignite

A lignite stockpile (above) and a lignite briquette

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%.^[1] 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.

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

• "Coal and lignite domestic consumption". Global Energy Statistical Yearbook. 2016.
• Geography in action – an Irish case study Archived 2010-07-22 at the Wayback Machine
• Photograph of lignite Archived 2010-04-19 at the Wayback Machine
• Coldry:Lignite Dewatering Process