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1. 发明专利

GB771310A Process for the manufacture of crude calcium cyanamide 未知
公开(公告)号：GB771310A
公开(公告)日：1957-03-27
申请号：GB1798353
申请日：1953-06-29
申请人： YUJI MINEMURA , ZENSUKE KUDO , KOSHO SHIRAKAWA , ISAO SATO , NOBORU SEKI , YOSHIHIRO MATSUMOTO , YUJI UCHIYAMA , YOSHITOSHI IWATA , TSUNEO NAKAJIMA
IPC分类号： C01C3/00
摘要： In the production of fine granular calcium cyanamide from calcium carbide and gaseous nitrogen in a fluidized bed, the bed is maintained at a substantially constant temperature above 800 DEG C., but below the fusion temperature of calcium cyanamide, e.g. 1000 DEG C., and the concentration of calcium carbide in the bed is maintained at below 30 per cent by weight of the bed to prevent sintering. Solid catalyst, e.g. calcium fluoride or chloride, may be included in the bed, which otherwise comprises calcium cyanamide, calcium oxide and carbon, but it is preferred, instead of solid catalyst, to add a small amount, say 0.3 per cent, chlorine to the nitrogen stream. It is stated that at the high temperatures used, the reactant particles become coated with a film of fused material, presumably calcium cyanide, which increases reaction velocities. The product from the fluidized bed is desirably further treated with N2 in a fixed bed. It is suitable to divide the reaction zone into several fluidized beds, through which reaction materials pass successively, to conserve heat, and apparatus is described having two superposed fluidized beds, or three adjacent fluidized beds separated by radial partitions. Specifications 688,188 and 690,949 are referred to.

2. 发明专利

GB737520A Improvements in processes for the production of white calcium cyanamide 未知
公开(公告)号：GB737520A
公开(公告)日：1955-09-28
申请号：GB1869553
申请日：1953-07-06
申请人： YUJI MINEMURA , NOBORU SEKI , YUJI UCHIYAMA
IPC分类号： C01C3/18
摘要： Calcium cyanamide is produced by fluidizing calcium carbonate in a stream of gas comprising ammonia at a temperature of for example 400-850 DEG C. The temperature may be lower if the calcium carbonate is in very finely divided form. The water vapour produced by the reaction is removed as quickly as possible and the partial pressure thereof in the reaction zone maintained as low as possible, i.e. by employing rapid gas flow and an ammonia gas stream diluted with inert gas, for example carbon dioxide, flue gas, electric furnace waste gas, hydrogen or nitrogen. These gases also inhibit ammonia decomposition. Solid ammonia decomposition inhibitors can be mixed with the calcium carbonate, for example silica gel, active carbon, alumina or calcium sulphide. The reaction may be effected in and around pipes coated with an ammonia decomposition inhibitor, e.g. pure aluminium or fused or powdered aluminium oxide. A number of fluidized beds arranged in series may be employed. A gas flow of at least 2 cm./sec. and a proportion of ammonia in the gas of below 50 per cent may be employed.

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