In the smelting process for iron and steel, coke serves as the source of carbon, which works as a reducing agent when reducing iron ore in the BF. At the same time, coke acts as the heat source for heating and melting the charged materials. Coke is made by baking coal in a coke oven. Coal is classified into the four grades shown in the figure, anthracite being the highest grade. Typical types are bituminous coal and brown coal. Bituminous coal exists in the largest quantities, having estimated reserves worldwide of approximately 7 trillion (trillion=1012)tons, with confirmed reserves of approximately 2 trillion tons. The coke used in the BF must have a high carbon content and low ash and sulfur contents, and must have an appropriate porosity as well as good strength to ensure that it gives good reactivity and does not pulverize to choke the gas flow in the BF even at high temperatures. Cokes that meet these requirements are derived from bituminous coals that combine good coking properties with low ash and sulfur contents. In the coke oven, the raw coal obtained by crushing and blending is charged into the coke chamber, where it is then baked (carbonized) by indirect heating at 1,473-1,573K (1,200-1,300) for 14-18 hours to form coke that contains about 90% fixed carbon. The coking process also produces such by-products as gas, coal tar, and pitch which can be refined and treated into useful secondary products such as fuel gas, pure hydrogen gas, chemical products such as benzene, toluene, xylene, naphthalene, dye, and carbon fibers. The life of a coke oven is about 40 years. In Japan, the lives of the coke ovens now in operation will begin to expire successively about the year 2015, which is expected to result in a shortage of coke. However, to cope with this problem, pulverized coal injection, in which coal with a poor coking property is injected through the tuyeres into the BF, is widely used. In addition, technical developments are being made to provide new technology to (i) produce coke or (ii) establish a cokeless iron making process, both of which will make it possible to select raw coal materials more freely and will cause less environmental pollution.