This the rock where coke is extracted. It is called Coking Coal. Coal is not involved with making steel.
Quality coking coal, (click here) also known as metallurgical coal, maximizes productivity in steel production.
Coke is produced by heating coking coals in a coke oven in a reducing atmosphere. As the temperature of the coal increases, it becomes plastic, fusing together before resolidifying into coke particles. This is known as the caking process. The quality of the resultant coke is determined by the qualities of the coking coals used, as well as the coke plant operating conditions.
Coke quality is largely influenced by coal rank, composition, mineral content and the ability to soften when heated, become plastic, and resolidify into a coherent mass. Bituminous class coals of high, medium, and low volatile rank that possess these properties are called “coking” coals.
High quality coking coals are in great demand by steel producers, who need these coals to make high quality coke to maximize the productivity of their blast furnace operations.