Sharma Coal Depot.

Anthracite is the highest rank coal and is characterized buy low volatile matter (always less than 10%) and high carbon content. It has a semi- metallic luster and is capable of burning without smoke. Semi- anthracite is coal midway between low volatile bituminous coal and anthracite.

Bituminous coal is that coal which in rank is between sub-bituminous coal and semi- anthracite. Volatile matter on dry ash free basis range from between 10% and 14% to 40% and over. Usually divided into three sub groups- low volatile medium volatile and high volatile.

Sub- bituminous coal is the next highest coal in rank after lignite. Typical bed moisture levels are 10-20%, and calorific value also enters in to the classification scheme.

Lignite is a low rank coal containing high moisture. Generally a coal is considered to be a lignite if it contains greater than 20% bed moisture (classification schemes for lignite are generally based on calorific value). Other characteristics of lignite are low reflectance, high volatile matter as high oxygen and low carbon and low carbon level and often the presence of some woody structure. In general the term is synonymous with brown coal.

Peat is the first stage in the conversion of vegetable matter to coal. Bed moistures are high, often greater than 75% and plant remains are clearly visibl

The inorganic residue after the incineration of coal to constant weight under standard conditions. Is less than the mineral matter because of the chemical changes occurring during incineration, with most important differences being loss of water of hydration, loss of carbon dioxide, and loss of sulphurous gases from sulphides.