coke

1. From coal: Pressed solid residue obtained from the destructive distillation of bituminous coal in which it is baked in an oven in the absence of oxygen to vaporize volatile constituents and fuse carbon and fly-ash together. About 90 percent carbon, it has a heating value of about 25 million Btu per ton. This type of coke is consumed primarily in smelting of iron in blast furnaces generally in the ratio of about 550 kilograms (roughly 1200 pounds) of coke to one ton of pig iron.

2. From oil: Pressed solid residue obtained from the cracking of petroleum, generally in the ratio of five barrels of oil to about 900 kg. (roughly 2000 pounds) of coke. About 95 percent carbon, it has a heating value of about 26.5 million Btu per ton, and is consumed primarily in manufacture of synthesis gas and carbon electrodes, and as refractory lining for arc furnaces.