Typo of Coal Spesification

Hard coal has a calorific value of more than 5,700 kcal/kg (23,26 MJ/kg). Hard coal consists of steam coal, coke, bituminous coal and anthracite.
Brown coal has a low calorific value including lignite and sub bituminous coal that can be used as fuel for power plants.

Steam coal is used by boiler/steam generators and heating ovens. Steam coal includes anthracite and bituminous coal. Its Gross Calorific value is larger than 23,865 kJ/kg (5,700 kcal/kg).

Coke could be used as a reductor in blast furnace. Its gross calorific value is larger than 23,865 kJ/kg (5700 kcal/kg), which free from dust.

Sub bituminous coal has a gross calorific value of 17,435 kJ/kg (4165 kcal/kg) and 23,860 kJ/kg (5,700 kcal/kg).

Anthracite is the highest in quality with calorific value of more than 6900 kcal/kg. It has the characteristics like those of steam coal.

** Lignite has a gross calorific value of less than 4,165 kcal/kg (17,44 MJ/kg) containing volatile matters of more than 31% in dry form. Lignite is often called Low Rank Coal, or Brown Coal.
** Coke is the result of carbonization of steam coal under high temperature. Coke is used as a redactor in steel smelting.
Most coal deposits in the country date back to the tertiary age formed 65 million years ago. Most or 83% of them have brown coal in the category of lignite and sub-bituminous, with a small part (20%) in the categories of Bituminous and Anthracite.
Indonesian coal is known to have low dust and sulfur contents, therefore, is more suitable to function as fuel or as steam coal causing less pollution.