Reduceness of coals

REDUCENESS OF COALS (EN: restorability of coal, recoverability of coal; DE: Reduktionsfaktor der Kohlen, Reduzierbarkeit der Kohlen; FR: reductibilite des charbons; ES: recuperabilidad de los carbones; RU: восстановленность углей) is the difference of the chemical, physical, and sintering properties of the coals with the equal degree of the coalification and petrographic composition, which are caused by the character of the original vegetation, and by the conditions of its transformation during the starting stages of the coalification. The reduced coals are characterized by the increased carbon content and by the decreased oxygen content, by the higher yield of the volatile substances and by the better sinterability, by the higher calorific value, by the high yield of the tars of the coking and semicoking, by the higher contents of the sulfur and basic oxides (mainly of the iron oxides), of the mineral admixtures, and by the decreased mechanical strength. According to the degree of the reduceness, they distinguish among the coals the three types (strongly reduced, intermediately reduced, weakly reduced), or the four types (very reduced, reduced, intermediate, slightly reduced).