Method and device for crystallizing and separating dicyandiamide

A technology of crystallization separation and dicyandiamide, applied in crystallization separation, separation method, heat exchange cooling crystallization and other directions, can solve the problems of environmental pollution, complex process, low crystal purity, etc., to improve the collection efficiency and product yield, The effect of short process flow

Pending Publication Date: 2021-11-09
SICHUAN GOLDEN ELEPHANT SINCERITY CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a dicyandiamide crystallization and separation method and device to solve technical problems such as low crystallization purity, complex process and high energy consumption, and environmental pollution in the prior art.

Method used

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  • Method and device for crystallizing and separating dicyandiamide

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] A dicyandiamide crystallization separation method, the method is to use the above-mentioned device to utilize the dicyandiamide process hot gas produced by the gas phase polymerization of cyandiamide, its main components include at least ammonia, CO2, dicyandiamide and other media, the temperature is 550 ° C, The pressure is 0.6Mpa, the process hot gas inlet 6 set on the top of the crystallizer 1 enters the crystallizer 1, and the process cold air enters the interior of the crystallizer 1 from the process cold air inlet 7. The medium of the process cold air is a mixture of ammonia and CO2. The temperature of the cold air is 150°C, and the pressure is 0.6Mpa. The process cold air is mixed with the process hot air, and the temperature after mixing is 200°C, and a gas-solid mixture is formed, which flows out from the process gas outlet provided at the bottom of the crystallizer 1.

[0037] The medium flowing out from the process gas outlet at the bottom of the crystallizer ...

Embodiment 2

[0040] A dicyandiamide crystallization separation method, the method is to use the dicyandiamide process hot gas produced by the gas phase polymerization of cyandiamide, its main components include at least ammonia, CO2, dicyandiamide and other media, the temperature is 250 ° C, the pressure is 0.3 Mpa, the process hot gas inlet 6 set on the top of the crystallizer 1 enters the crystallizer 1, and the process cold air enters the crystallizer 1 from the process cold air inlet 7. The medium of the process cold air is CO2 gas, and the temperature of the process cold air is 100 ° C. The pressure is 0.6Mpa. The process cold air is mixed with the process hot air, and the temperature after mixing is 150°C, and a gas-solid mixture is formed, which flows out from the process gas outlet provided at the bottom of the crystallizer 1 .

[0041] The medium flowing out from the process gas outlet at the bottom of the crystallizer 1 is a gas-solid two-phase, wherein the solid phase is a solid ...

Embodiment 3

[0044] A dicyandiamide crystallization separation method, the method is to use the dicyandiamide process hot gas produced by the gas phase polymerization of cyandiamide, its main components include at least ammonia, CO2, dicyandiamide and other media, the temperature is 350 ° C, the pressure is 0.4 Mpa, the process hot gas inlet 6 set on the top of the crystallizer 1 enters the crystallizer 1, and the process cold air enters the crystallizer 1 from the process cold air inlet 7. The medium of the process cold air is NH3 gas, and the temperature of the process cold air is 20 ° C. The pressure is 0.3Mpa. The process cold air is mixed with the process hot air, and the temperature after mixing is 80°C, and a gas-solid mixture is formed, which flows out from the process gas outlet provided at the bottom of the crystallizer 1 .

[0045]The medium flowing out from the process gas outlet at the bottom of the crystallizer 1 is a gas-solid two-phase, wherein the solid phase is a solid con...

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Abstract

The invention discloses a method and device for crystallizing and separating dicyandiamide, belonging to the technical field of dicyandiamide production. The method comprises the following steps: S1, introducing hot gas of a dicyandiamide process into a crystallizer; S2, introducing cold air of a process into the crystallizer, and mixing the cold air of the process with the hot air of the dicyandiamide process to form a gas-solid mixture; and S3, discharging the gas-solid mixture out of the crystallizer, and introducing the gas-solid mixture into a gas-solid separator to obtain a dicyandiamide solid. The whole flow process is free of pollution, the technological process is free of decalcification reaction and process waste residues, a unique gas-phase cooling crystallization process is adopted, and no process waste water is generated.

Description

technical field [0001] The invention belongs to the technical field of dicyandiamide production, in particular to a dicyandiamide crystallization separation method and device. Background technique [0002] Dicyandiamide, also known as dicyandiamide, abbreviated as DICY or DCD. It is a dimer of cyanamide and a cyano derivative of guanidine. Chemical formula C 2 h 4 N 4 . White crystal powder. Soluble in water, alcohol, ethylene glycol and dimethylformamide, almost insoluble in ether and benzene. Stable when dry. Dicyandiamide is mainly a derivative of lime nitrogen. [0003] The traditional traditional process route of dicyandiamide is obtained by "carbide-lime nitrogen-calcium cyanamide-calcium removal-crystallization"; calcium carbide undergoes nitriding reaction to generate lime nitrogen, and lime nitrogen undergoes hydrolysis to generate calcium cyanamide, Calcium cyanamide is then decalcified with CO2 to generate cyanamide, which is then polymerized into a dicya...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C279/28C07C277/08B01D9/00
CPCC07C277/08B01D9/0004C07C279/28
Inventor 唐印孔德利雷林宋国天莫玉馨刘朝慧秦艳妮
Owner SICHUAN GOLDEN ELEPHANT SINCERITY CHEM CO LTD
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