Abstract: The invention relates to a process for making calcium carbide by reacting an excess of coke with quicklime in the presence of oxygen in an oxygen-thermal furnace. To this end, the invention provides for precrushed coal to be used as starting material for coke and precrushed lime hydrate (Ca(OH).sub.2) or precrushed limestone (CaCO.sub.3) to be used as a starting material for quicklime. The precrushed materials are mixed and the resulting mixture is introduced into a drying zone and freed therein at 80.degree. to 120.degree. C. from adhering water. Next, the warm mixture coming from the drying zone, and air, are introduced into a calcining apparatus in which the coal constituent is coked and the lime constituent is simultaneously dehydrated or decarbonized, at temperatures of 900.degree. to 1400.degree. C. The thermally-pretreated mixture of starting materials with an inherent temperature of 900.degree. to 1000.degree. C.

Abstract: A method of producing abrasion resistant coke from brown coal briquets in a shaft furnace comprises charging the coke briquets into the top of the furnace and removing coke from the bottom of the furnace while directing inert hot combustion gases into the furnace and through the briquets at a plurality of vertically spaced levels throughout the height of the shaft furnace. Gases are directed at temperatures to effect and successively lower stages of the furnace the preheating, predrying, carbonization, and cooling of the charge.

Abstract: A method of producing abrasion resistant coke from brown coal briquets in a shaft furnace comprises charging the coke briquets into the top of the furnace and removing coke from the bottom of the furnace while directing inert hot combustion gases into the furnace and through the briquets at a plurality of vertically spaced levels throughout the height of the shaft furnace. Gases are directed at temperatures to effect and successively lower stages of the furnace the preheating, predrying, carbonization, and cooling of the charge. Gases are collected in each of the preheating and predrying stages by the use of a tubular suction arm which extends substantially across the width of the furnace and includes a performated bottom and sidewalls which extend partly below the bottom and are provided with a saw-tooth configuration so as to withdraw the gases through the space below the bottom and through the perforations of the bottom and to effect entrainment of dust from the charge in so doing.