Coking is made by heating COAL in coke ovens to drive volatile matter from it. 
Ovens are heated by coke-oven gas, which burns in heating flues in an oven's 
side walls. Waste gases from this combustion pass out through a stack or chimney. 
At either 20- or 30-minute intervals, the flows of gas, air and waste gas are 
reversed to maintain uniform temperature distribution across the wall. 
The design of heating systems varies from battery to battery. Approximately
40 percent of the total coke oven gas produced from coking is returned to 
the heating flues for burning after having passed through various cleaning 
and coproduct recovery processes. 

Coke is shipped in open hoppers, boxes and bags in box cars. Dry Coke is shipped in closed pnuematically unloaded hoppers.
Metallurgical Coke is used as a fuel and reducing agent in the production of PIG IRON, steel, ferro-alloys, elemental phosphorus, calcium carbide and numerous other processes. It is also used to produce carbon electrodes and to agglomerate sinter and iron ore pellets. Screening of the coke provides the following primary products: nut coke (larger than 3/4 inch) buckwheat coke (between 3/16 and 3/4 inch) coke breeze (less than 3/16 inch). Petroleum Coke is used as a substitute for coal in the manufacture of blast furnace coke, in the production of cement and lime, and to generate electric power. In many cases, petroleum coke is blended with other industrial carbons to achieve an economical solution to rising raw material costs. Dry Coke can be utilized as a charge carbon, carbon raiser, injection carbon, foaming slag additive, ladle carbon additive, and a packing core for electrode production. Dry coke is available in bulk, bagged, or supersacked.
S.A. McCall