Metallurgical coal or coking coal is used in the process of creating coke necessary for iron and steel-making. Coke is a porous, hard black rock of concentrated carbon specifications : Typical cargo specifications: Moisture: 10% max Ash: 14% max Volatile Matter: 2% max Fixed Carbon: 84% min Sulfur: 0.8% max Phosphorus: 0.05% max Size: 5 -25 mm