It is used primarily for the generation of electricity and steel production. The increase in rank describes an increase in temperature and pressure which results in the coals having a lower volatile content, therefore increased carbon content. Coal is also classified according to its sulphur, phosphorous, volatile and ash contents, whose proportions generally vary according to its rank. Coking coal is used in the steel making industry whereby the coal requires specific qualities such as low sulphur and phosphorous contents. Approximately 630 kg of coal are used for every ton of steel produced.
Electricity generation uses thermal coal, which is ground to a fine powder prior to combustion.
China, Australia and India are the world's major coal producers.