Preparation method of high-concentration cyanamide solution

A cyanamide and high-concentration technology, applied in the direction of thiocyanate, etc., can solve the problems of high production cost, large equipment investment, and long production cycle, and achieve the effects of low cost, good product quality, and short production cycle

Active Publication Date: 2014-09-17
SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] Aiming at the shortcomings of large equipment investment, high energy consumption, long production cycle and high production cost in the existing production method of cyanamide solution with a mass fraction of 50%, the invention provides a method for preparing high-concentration cyanamide, through Add a polymerization inhibitor to the reaction system to prevent the binary polymerization of cyanamide to form dicyandiamide, and then use four batches of mother liquor to react, and finally obtain a high-concentration cyanamide solution

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  • Preparation method of high-concentration cyanamide solution
  • Preparation method of high-concentration cyanamide solution
  • Preparation method of high-concentration cyanamide solution

Examples

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Effect test

Embodiment 1

[0022] (1) Add 300g of water and 1.5g of hydroquinone into a 500ml four-necked flask equipped with a thermometer, condenser and stirrer, and inject carbon dioxide gas with a mass fraction ≥ 50% from the bottom of the solution, and stir rapidly. Gradually add 150g of lime nitrogen (containing 20.5% nitrogen), control the solution temperature at 5°C, wait until the pH of the solution is 9, stop the reaction, filter to obtain 270g of cyanamide aqueous solution and filter residue, weigh 30g of water to wash the filter residue;

[0023] (2) After mixing the water-washed filtrate and the cyanamide aqueous solution I obtained in step (1), add it in a 500-milliliter four-neck flask equipped with a thermometer, a condenser and a stirrer, and continue to repeat the operation of step (1) to obtain cyanamide Aqueous solution 268g and filter residue, then wash filter residue with 32g water;

[0024] (3) After mixing the aqueous cyanamide solution obtained in step (2) and the washing filtra...

Embodiment 2

[0027] (1) Add 600g of water and 1.2g of 4-tert-butylcatechol into a 1000ml four-neck flask equipped with a thermometer, condenser and stirrer, and inject carbon dioxide gas with a mass fraction ≥ 50% from the bottom of the solution, and quickly Stir, gradually add 150g of lime nitrogen (containing 20.5% nitrogen), control the solution temperature at 10°C, wait until the pH value of the solution is 8, stop the reaction, filter to obtain 551.0g of cyanamide aqueous solution and filter residue, weigh 49g of water to wash the filter residue;

[0028] (2) After mixing the water-washed filtrate and the aqueous cyanamide solution obtained in step (1), add it into a 1000 ml four-neck flask equipped with a thermometer, a condenser and a stirrer, and continue to repeat the operation of step (1) to obtain an aqueous solution of cyanamide 542g and filter residue, then wash the filter residue with 58g water;

[0029] (3) After mixing the aqueous cyanamide solution obtained in step (2) and...

Embodiment 3

[0032](1) Add 1200g of water and 1.2g of benzoquinone to a 2L reactor equipped with a thermometer, a condensing device and an agitator, and introduce carbon dioxide gas with a mass fraction ≥50% from the bottom of the solution, stir rapidly, and gradually add 400g of lime nitrogen (containing 20.5% nitrogen), control the temperature of the solution at 15°C, wait until the pH value of the solution is 7, stop the reaction, filter to obtain 1121g of cyanamide aqueous solution and filter residue, weigh 79g of water to wash the filter residue;

[0033] (2) Mix the cyanamide aqueous solution obtained in step (1) with the washing filtrate and add it to a 2L reactor equipped with a thermometer, a condensation device and a stirrer, and continue to repeat the operation of step (1) to obtain 1089 g of cyanamide aqueous solution and filter residue , then wash the filter residue with 111g of water;

[0034] (3) Mix the cyanamide aqueous solution obtained in step (2) with the washing filtra...

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Abstract

The invention discloses a preparation method of a high-concentration cyanamide solution. The preparation method is carried out by the following steps of: adding a polymerization inhibitor into a reaction system to prevent cyanamide from implementing binary copolymerization and generating dicyandiamide, meanwhile filling carbon dioxide gas in an aqueous solution, controlling the reaction temperature and a reaction pH value, stirring till the reaction is complete, filtering to obtain a cyanamide solution with a certain concentration and filter residues, then using a certain amount of water to wash the filter residues, mixing the obtained filter liquor with the cyanamide solution as a mother liquor, carrying out the second batch of reaction with the steps, and carrying out a plurality of batches of reaction by using mother liquors to obtain the cyanamide solution with the concentration of the mass fraction greater than 50%. The process has the advantages of high yield, good product quality, short production periods and low cost, is suitable for large-scale industrial production and also has the advantages of good social benefits and economic benefits.

Description

technical field [0001] The invention relates to a preparation method of a high-concentration cyanamide solution. Background technique [0002] The chemical name of cyanamide is cyanamide, also known as aminocarbonitrile, and the English name is Cyanamide. It is colorless, easy to deliquescence, orthorhombic crystallization, melting point 45°C, and has a high solubility in polar organic solvents such as lower alcohols, esters and ketones. , The solubility in non-polar solvents is small, and the solubility in water is large. Cyanamide contains a cyano group and an amino group, both of which are active groups, have the multiple reactivity of the above functional groups, and are prone to reactions such as addition, substitution, and condensation. [0003] As an important chemical raw material, cyanamide is widely used in the manufacture of fine chemical products, pharmaceutical raw materials and pesticide raw materials. Cyanamide can be used as a chemical intermediate to produ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01C3/20
Inventor 龙显灵吴文雷马韵升史庆苓栾波樊其艳郭龙龙
Owner SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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