Metallurgical coal is a special type of coal used to make metallurgical coke. There are two types of metallurgical coal used to make coke: hard coking coal and semisoft coking coal. According to Grande Cache Coal, these types of coal are ideal for coke because they melt, swell and re-solidify when placed into a superheated furnace. These types of coal also have have low levels of impurities.
Metallurgical coke is made from low ash, low sulfur bituminous coal, with special coking properties, which is inserted into ovens and heated to 1000F to fuse fixed carbon and inherent ash and drive off most of the volatile matter.
Metallurgical coal is distinguished by the strong low-density coke produced when the coal is heated in a low-oxygen environment to reduce mineral impurities (e.g. less sulfur, phosphorus). On heating, the coal softens, and volatile components evaporate and escape through pores in the mass. On cooling, the resultant coke has swollen, becoming a larger volume. The coking ability of coal is somewhat correlated with its physical properties such as its rank, but laboratory testing is required to completely evaluate the coking ability of the coal.
There has been rising demand for metallurgical coke from the iron, steel and power generation industries. Metallurgical coke is formed by destructive distillation of a special blend of bituminous coal in the absence of air or oxygen. In order to produce metallurgical coke, the coal is heated into ovens at specific temperature to produce low sulphur, low phosphorus coke.
Coke is made by destructive distillation of a blend of selected Bituminous coals (called Coking coal or Metallurgical coal) in special high temperature ovens in the absence of oxygen until a greater part of the volatile matter is driven off.
The global metallurgical coke market is anticipated to be dominated by Asia Pacific region with China leading the market both in terms of production and consumption. India is also anticipated to witness sound growth in demand for metallurgical coke owing to the rapid growth in the iron and steel industry in the country.