Method for reducing dicyandiamide content in solution containing 30% of cyanamide

A technology of cyanamide and dicyandiamide, which is applied in the field of reducing the content of dicyandiamide in 30% cyanamide solution, can solve problems such as technical impossibility, undisclosed necessary technical features, and impact on product quality, so as to inhibit polymerization Effect

Active Publication Date: 2016-05-04
SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Cyanamide has active chemical properties and is relatively stable below 20°C. As the temperature rises, especially above the melting point, it is easy to decompose into dicyandiamide and urea, which affects the quality of the product.
Patent CN103553080A discloses a pro

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] A method for reducing the content of dicyandiamide in 30.0% cyanamide solution, the synthetic production steps are:

[0030] (1) Transfer mother liquor: add 4.0m 3 Mother liquor, accounting for 66.7% of the volume of the synthesis kettle, is fed with carbon dioxide, and the flow rate of carbon dioxide is controlled at 50.0m 3 / h, mother liquor pH=6.5, carbon dioxide continues to feed;

[0031] (2) Feeding: Open the synthesis kettle and stir, calcium cyanamide enters the synthesis kettle through the powder conveying system, the conveyor speed is 500 rpm, and the total amount of feeding is 1.0 tons, accounting for 16.7% of the synthesis kettle volume;

[0032] (3) Hydrolysis reaction: the flow rate of carbon dioxide fed to the synthesis kettle is adjusted to 150m 3 / h, the reaction temperature is controlled at 25.0°C by the cold water cooling system, the reaction time is 5.0 hours, pH=6.5;

[0033] (4) Heat preservation: The heat preservation time is 1.0 hours, and the...

Embodiment 2

[0039] A method for reducing the content of dicyandiamide in 30.0% cyanamide solution, the synthetic production steps are:

[0040] (1) Transfer mother liquor: add 4.0m 3 Mother liquor, accounting for 66.7% of the volume of the synthesis kettle, is fed with carbon dioxide, and the flow rate of carbon dioxide is controlled at 70.0m 3 / h, pH of the mother liquor=7.0, continuous feeding of carbon dioxide;

[0041] (2) Feeding: Open the synthesis kettle and stir, calcium cyanamide enters the synthesis kettle through the powder conveying system, the conveyor speed is 700 rpm, and the total amount of feeding is 1.0 tons, accounting for 16.7% of the synthesis kettle volume;

[0042] (3) Hydrolysis reaction: the flow of carbon dioxide fed to the synthesis kettle is adjusted to 100m 3 / h, the reaction temperature is controlled at 27.0°C by the cold water cooling system, the reaction time is 6.0 hours, pH=7;

[0043] (4) Heat preservation: The heat preservation time is 1.5 hours, and...

Embodiment 3

[0049] A method for reducing the content of dicyandiamide in 30.0% cyanamide solution, the synthetic production steps are:

[0050] (1) Transfer mother liquor: add 4.0m 3 Mother liquor, accounting for 66.7% of the volume of the synthesis kettle, is fed with carbon dioxide, and the flow rate of carbon dioxide is controlled at 60.0m 3 / h, mother liquor pH=6.5;

[0051] (2) Feeding: Open the synthesis kettle and stir, calcium cyanamide enters the synthesis kettle through the powder conveying system, the conveyor speed is 600 rpm, and the total amount of feeding is 1.0 tons, accounting for 16.7% of the synthesis kettle volume;

[0052] (3) Hydrolysis reaction: the flow rate of carbon dioxide fed to the synthesis kettle is adjusted to 130m 3 / h, the reaction temperature is controlled at 26.0°C by the cold water cooling system, the reaction time is 6.0 hours, pH=6.5;

[0053] (4) Heat preservation: The heat preservation time is 1.2 hours, and the carbon dioxide flow rate is contr...

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PUM

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Abstract

The invention discloses a method for reducing a dicyandiamide content in a solution containing 30% of cyanamide. Process of the related solution containing 30% of cyanamide comprises steps of: controlling a synthetic reaction temperature in a range of 25.0-27.0 DEG C, a PH value in a range of 6.5-7.0, and a reaction time in a range of 5.0-6.0 h; performing heat preservation after a synthetic reaction is over for 1.0-1.5 h; and obtaining the solution containing 30% of cyanamide, with the dicyandiamide content controlled to be no more than 0.5%. Raw materials required in the process comprise calcium cyanamide, carbon dioxide, and water. The method is simple in operation steps, and the reaction yield is more than 95.0%. The process is reasonable and reliable, and the product is stable in quality.

Description

technical field [0001] The invention relates to a method for producing cyanamide solution in the field of chemical production, in particular to a method for reducing the content of dicyandiamide in 30% cyanamide solution. Background technique [0002] Cyanamide is a kind of pharmaceutical raw material and intermediate, mainly used in the production of cytarabine hydrochloride, 3-amino-5-hydroxyl 1, 2, 4-triazole, etc. It is also a raw material for organic synthesis, such as the production of cyanuramide , dicyandiamide, cyanamide, carbamic acid, methyl ester, etc., and then produce pharmaceutical barbitic acid, sulfa drugs, various guanidine salts, pesticide Zhiyaling, carbendazim, creatine, etc. Cyanamide can be used as a plant growth regulator in agriculture, with both insecticidal and bactericidal effects. Especially in the production of cherries and grapes, it is a good dormancy terminator, which can lead to early flowering and fruiting, increase yield, and change fruit ...

Claims

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Application Information

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IPC IPC(8): C01C3/16
CPCC01C3/16Y02P20/141
Inventor 梁万根张宁姚凯史庆苓张超张永军李鹏
Owner SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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