Low Volatile Coal. High quality. Volatile – 9-15%, Sulfhur no more 0,6%, Net Calorific Value – 6000-6500, 6500-6800 kcal/kg. Mid Volatile Coal. High quality. Volatile – 17-33%, Sulfhur no more 0,6%, Net Calorific Value – 6000-6500 kcal/kg. High Volatile Coal. High quality. Volatile – 33-40%, Sulfhur no more 0,6%, Net Calorific Value – 5000-5500, 5500-6000 kcal/kg.