TYPES OF HARD COAL

Bituminous Coal

Bituminous coal is classified as coal which in terms of rank falls between sub-bituminous and semi-anthracite. Volatile matter can vary widely and bituminous coal is typically divided into three sub-groups - low volatile, medium volatile and high volatile. Bituminous coal can be metallurgical (also known as coking coal) or thermal (also known as steam coal).

Metallurgical/Coking Coal

This term is used to apply to a coal which can be usefully converted into coke i.e. one which gives a coke strong enough to resist pressure and breakage. The term coking coal covers a range of coals, the cokes from which serve different purposes depending primarily on the fixed carbon and volatile matter of the original coal.

Thermal/Steam Coal

This term is generally used to distinguish coals considered particularly suitable for boiler use ie for power generation.

Anthracite

Anthracite is the highest rank coal and is characterised by low volatile matter (always less than 10%) and high carbon content - it contains about 90% fixed carbon, more than any other form of coal. Anthracite has a semi-metallic lustre and is capable of burning without smoke (smokeless fuel). It is used in domestic and industrial applications. Anthracite is the least plentiful of all the coals.

In terms of world trade, anthracite is almost insignificant. However, it is the most high value coal product with only a few international suppliers. The main producers of anthracite include South Africa, PR China, Vietnam, FSU countries, Germany and the UK. The world traded anthracite market consists of two distinct sectors:

• sized anthracite - used mainly for household heating and specialised industries such as glass, chemicals and as a reductant;
• fine anthracite/semi-anthracite - used in the steel industry for pulverised coal injection (PCI), for sintering and briquetting and in the ferrometals market as a reductant.