GB744432A - Process for the manufacture of formed coke - Google Patents

Abstract

744,432. Making coke. STEINKOHLENBERGWERK HANNOVERHANNIBAL AKT.-GES. Oct. 15, 1953 [Oct. 16, 1952], No, 28486/53. Classes 55 (1) and 55.(2). In a process for the manufacture of formed coke in which solid fuels are briquetted with addition of a binder and the briquettes are coked the solid fuels are first degassed (if necessary) and ground, degassing (if required) either preceding or following grinding, the grinding following the degassing for fuels which tend to agglomerate during degassing, in such a way that (a) hard cokes such as are obtained from coking coal, or coking coals themselves are degassed to contain no more than 7 per cent volatile matter and preferably completely and,ground to a grain size of 4 mms. maximum, preferably. 2 mms. maximum, (b) or medium hard cokes such as are obtained from weakly coking or non-coking coals such as anthracite, non-bituminous coal and gas flame coal, or such coals themselves are degassed to contain no more than about 5 per cent volatile matter and preferably completely and ground to a grain size of 2 mms. maximum, preferably 1 mm. maximum, (c) or soft cokes such as are obtained from coals such as highly bituminous and brown coals, or such coals themselves are degassed to contain no more than about 4 per cent volatile matter and preferably completely and ground to a grain size of 2 mms. maximum, preferably 1 mm. maximum, (d) or cokes of particularly small grain strength such as are obtained from fuels such as boghead or cannel coals, peat, wood, lignite and the like, or such fuels themselves are completely degassed and ground to a grain size of 1 mm. maximum, preferably 0.5 mm. or finer maximum, (e) or fuels having already a high degree of carbonization such as anthracite, non-bituminous coals and other non-caking coals are ground to at least 1 mm. maximum and preferably, particularly in the case of non-bituminous coals, to at least 0.1 mm. and finer. The binder is preferably a material which is liquid during the briquetting, e.g. tar, pitch, bitumen, mineral oil residues or mixtures of these materials, and is preferably the tar arising during preliminary de-gassing and briquette coking. In cases of fuels which give very soft and friable coke on degassing, 1-3 per cent of tar or mineral oil residue may be added to the finely ground fuel before the degassing is effected to harden the coke structure. The briquettes are pressed at pressures of at least 500 kg/cm<SP>2</SP> and preferably between 600 -1,000 kg/cm<SP>2</SP>. The briquettes may be of egg- or cushion-shape of about 400 gms. weight or formed as cubes of 1 kg. or more. The final coking of the briquettes may be for 5-8 hours with an end temperature of 1000‹ C. or in small furnaces the coking may be complete in 3 hours. In the case of anthracite and non-bituminous coals which have not been de-gassed the coking period is extended to 10-12 hours and the coking is done at a slower rate. In an example a highly bituminous coal of 42 per cent volatile matter is ground to a grain size of 0.1 mm. and completely de-gassed at 1000‹ C. for more than 12 hours. 92 per cent of the resulting fine-ground coke is mixed with 8 per cent tar and briquetted under a pressure of 700 kg/.cm<SP>2</SP> to form cushion-shaped briquettes of 200 gms. in weight. The briquettes are coked for 5-8 hours with an end temperature of 1000‹ C.