Abstract: In a coking process wherein coal is subjected to coking in chamber furnaces by means of combustion of a fuel gas in the heat flues of the furnace and transfer of the generated heat through the walls of the furnace, the heat supply is effected, during the entire course of the coking operation, according to a preestablished programmed control scheme related to a uniform or mean rate of heat supply, the supply of heat being at a maximum at the commencement of the coking operation and being gradually reduced during the continuing coking operation.

Abstract: The output of coke ovens is increased if the brick constituting the wall between the flues and the coking chamber has a thermal conductivity matched to the rate at which the coke accepts heat. Magnesite has been found to have appropriate thermal conductivity. This material at the lower end of the coking range, namely 1200.degree. C, is impractical due to the fact that it develops cracks and flakes off. However at the higher end of the desired coking range, namely 1300.degree.-1400.degree. C, these difficulties do not appear, and the use of the material leads to increased output of the furnace. More particularly according to the invention firebrick is used which has a thermal conductivity of 2.0-6.0kcal/mh.degree. C and is composed of 20-45% SiC, 23-57% Al.sub.2 O.sub.3 with the remainder consisting of SiO.sub.2 and traces of other oxides.

Abstract: Improvements in the process of producing coke from bituminous coal in high-efficiency coking ovens, whereby the size of the lumps of coke and their strength are both increased, which comprises maintaining a coking rate between 1.2 and 2.8, and preferably between 1.44 and 2.0, inches per hour, based upon the width in inches of the coking chamber and the time required to complete the coking operation, and maintaining a rate of temperature increase between 1.6 and 3.3 centigrade degrees per minute during the heating of the coal while it is in the plastic range. The coal preferably is also preliminarily heated to a temperature between 160.degree. and 250.degree.C, preferably between 180.degree. and 200.degree.C, before being charged to the high-efficiency coking oven, and the width of the coking chamber of the high-efficiency oven that is used is at least 500 millimeters (19.7 inches).