cokeA hard, gray, carbonaceous residue derived from low-ash, low-sulfur bituminous coal from which the volatile components are driven off by heating in a special furnace at temperatures as high as 2,000°F so that the fixed carbon and residual ash are fused together. Before the exploitation of natural gas, much coal gas was thus produced for use as a fuel (heating value of 24.8 million BTU per ton) and also to make water gas. Today, most coke is used as a reducing in metallurgy, mostly in blast furnaces. Such coke must be strong (to support the weight of the charge), porous, and relatively pure. Related categories INDUSTRIAL CHEMISTRY• ORGANIC CHEMISTRY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |