Of the four types of coal, anthracite is the hardest and contains the highest heat value. It is almost pure carbon and is used mainly for home heating and cooking. In some developing countries, it is also used for industrial purposes. Found on http://www.rocksandminerals.com/glossary.htm
Of the four types of coal, anthracite is the hardest and contains the highest heat value. It is almost pure carbon and is used mainly for home heating and cooking. In some developing countries, it is also used for industrial purposes.