Metallurgical coke is produced by the destructive distillation of coal in coke ovens. Prepared. coal is heated in an oxygen-free atmosphere (–coked–) until most volatile components in the coal are. removed. The material remaining is a carbon mass called coke. Metallurgical coke is used in iron and steel industry processes (primarily in blast furnaces) to. reduce iron ore to iron. Over 90 percent of the total coke production is dedicated to blast furnace. operations.