Preparation method of 30% cyanamide aqueous solution

A technology of aqueous solution and cyanamide, which is applied in the field of preparation of 30% cyanamide aqueous solution, and achieves the effect of low cost, high yield and good product quality

Inactive Publication Date: 2018-12-14
SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Aiming at the deficiencies in the prior art, the present invention aims to provide a method for preparing lime nitrogen by using thiourea slag and using it for the production of cyanamide, the method directly produces 30% cyanamide by adjusting t

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] A preparation method of 30% cyanamide aqueous solution is characterized in that it comprises the following steps:

[0024] (1) Preparation of lime nitrogen: mix industrial solid waste and urea at a material ratio of 1:3, then grind, calcine at 280°C under nitrogen protection for 3 hours, then heat to 750°C and continue calcination for 4 hours. After the reaction is complete, nitrogen atmosphere Cool down to room temperature, and grind the obtained crude lime nitrogen for use;

[0025] (2) Preparation of 30% cyanamide aqueous solution: In the case of continuous introduction of carbon dioxide in the water, the prepared lime nitrogen was added in batches and the reaction was stirred. The process control temperature was 20°C and the pH value was 7.5. After the reaction, it was separated by filtration. Obtain the cyanamide primary material liquid, continue to add the lime nitrogen secondary material to the primary material liquid in batches, add phosphoric acid to neutralize the ...

Embodiment 2

[0028] A preparation method of 30% cyanamide aqueous solution is characterized in that it comprises the following steps:

[0029] (1) Preparation of lime nitrogen: mix industrial solid waste and urea at a material ratio of 1:1.5, then grind, calcine at 200°C for 2h under nitrogen protection, then heat to 600°C and continue calcination for 3h. After the reaction is complete, nitrogen atmosphere Cool down to room temperature, and grind the obtained crude lime nitrogen for use;

[0030] (2) Preparation of 30% cyanamide aqueous solution: In the case of continuous introduction of carbon dioxide in the water, the prepared lime nitrogen is added in batches and the reaction is stirred at one time. The process control temperature is 15°C and the pH value is 6. After the reaction is completed, it is separated by filtration Obtain the cyanamide primary material liquid, continue to add the lime nitrogen secondary material to the primary material liquid in batches, add phosphoric acid to neutra...

Embodiment 3

[0033] A preparation method of 30% cyanamide aqueous solution is characterized in that it comprises the following steps:

[0034] (1) Preparation of lime nitrogen: mix industrial solid waste and urea according to the material ratio of 1:5, then grind, calcinate at 350℃ for 4h under nitrogen protection, then heat to 850℃ to continue calcination for 6h, after the reaction is finished, nitrogen atmosphere Cool down to room temperature, and grind the obtained crude lime nitrogen for use;

[0035] (2) Preparation of 30% cyanamide aqueous solution: In the case of continuous introduction of carbon dioxide in the water, the prepared lime nitrogen was added in batches and the reaction was stirred at one time. The process control temperature was 30°C and pH value 9. After the reaction, it was separated by filtration. Obtain the cyanamide primary material liquid, continue to add the lime nitrogen secondary material to the primary material liquid in batches, add phosphoric acid to neutralize t...

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PUM

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Abstract

The invention belongs to the chemical field and particularly relates to a preparation method of a 30% cyanamide aqueous solution. According to the method, solid waste produced in industrial productionof thiourea is used as a raw material and reacts with urea at high temperature to prepare lime nitrogen, a cyanamide liquid is prepared under the action of water and CO2, lime nitrogen is added to the liquid secondarily, phosphoric acid is added to control the pH of the system, filtration and separation are performed after the reaction, and the 30% cyanamide aqueous solution with the pH value inthe range of 4-5 is obtained. The designed production process of the 30% cyanamide aqueous solution can change thiourea residues into wealth and has the advantages of high yield, low cost, good product quality and the like, and an economical and effective solution is provided for reutilization of thiourea residues and preparation of 30% cyanamide.

Description

Technical field [0001] The invention belongs to the field of chemical engineering, and specifically relates to a preparation method of a 30% cyanamide aqueous solution. Background technique [0002] The chemical name of cyanamide is cyanamide. The cyanamide contains a cyano group and an amino group, both of which are active groups. They have the multiple reaction properties of the above functional groups and are prone to addition, substitution, condensation and other reactions. [0003] Cyanamide solution is used as a defoliant and non-toxic insecticide for fruit trees abroad. Crystalline cyanamide is mainly used in the synthesis of medicines, health products, feed additives and pesticide intermediates, and has a wide range of uses. Cyanamide is an important pesticide intermediate. It can be used to prepare the fungicides carbendazim, benomyl, methamphetamine, azoxystrobin, the insecticide pyrimicarb, pyrimidinox, and the herbicide chlorsulfuron, methanesulfonate Methylsulfuron, ...

Claims

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Application Information

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IPC IPC(8): A01N59/24C01C3/16A01P7/04A01P21/00
CPCA01N59/24C01C3/16
Inventor 马韵升张超梁万根于龙张宁崔卫华
Owner SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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