Lignite:
1. Lignite is a brown coloured coal of lowest grade.
2. It has least content of carbon. The carbon content of lignite is 25 – 35%.
3. Lignite contains a high amount of water and makes up almost half of our total coal reserves.
4. It is used for electricity generation.
5. It is used to generate synthetic natural gas and produce fertilizer products.
Sub-bituminous:
1. When lignite becomes darker and harder over time, sub-bituminous coal is formed.
2. Sub-bituminous coal is a black and dull coal.
3. It has higher heating value than lignite and contains 35-44% carbon.
4. It is used primarily as fuel for electricity power generation.
5. This coal has lower sulfur content than other types and bums cleaner.
Bituminous:
1. With more chemical and physical changes, sub-bituminous coal is developed into bituminous coal.
2. It is dark and hard. It contains 45-86% carbon. It has high heating value.
3. It is used to generate electricity.
4. Other important use of this coal is to provide coke to iron and steel industries.
5. By-products of this coal can be converted into different chemicals which are used to make paint, nylon and many other items.
Anthracite:
1. It is the highest grade coal. It is hard and dark black in colour.
2. It has a very light weight and the highest heat content.
3. Anthracite coal is very hard, deep black and shiny.
4. It contains 86-97% carbon and has a heating value slightly higher than bituminous coal.
5. It bums longer with more heat and less dust.
