Clean preparation method of aqueous cyanamide solution

A technology of cyanamide and aqueous solution, which is applied in the direction of cyanamide, etc., can solve the problems of no commercial value, calcium carbonate solid waste, etc., and achieve good environmental protection benefits, low cost, and high yield effects

Inactive Publication Date: 2018-07-20
SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method is mature and widely used, but a large amount of calcium carbonate solid waste is produced in the process, which has no commercial value, and it is a headache to deal with, which brings great pressure to environmental protection

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] A clean preparation method for an aqueous solution of cyanamide, using calcium carbonate solid waste produced in the industrial production of cyanamide as a raw material, reacting with urea at high temperature to prepare lime nitrogen, and then preparing an aqueous solution of cyanamide under the action of water and carbon dioxide, At the same time, the recovery, recycling and reuse of calcium carbonate are realized.

[0020] Include the following steps:

[0021] (1) Preparation of lime nitrogen: Mix the industrial solid waste calcium carbonate with urea and grind it, and then calcined at 260°C for 2h under the protection of nitrogen, then raised the temperature to 750°C and continued to calcinate for 4h, and cooled to room temperature under nitrogen atmosphere after the reaction. Lime nitrogen crude product is ground, standby;

[0022] (2) Calcium carbonate recovery: In the case of continuous introduction of carbon dioxide into the water, the lime nitrogen prepared in...

Embodiment 2

[0030] A clean preparation method for an aqueous solution of cyanamide, using calcium carbonate solid waste produced in the industrial production of cyanamide as a raw material, reacting with urea at high temperature to prepare lime nitrogen, and then preparing an aqueous solution of cyanamide under the action of water and carbon dioxide, At the same time, the recovery, recycling and reuse of calcium carbonate are realized.

[0031] Include the following steps:

[0032] (1) Preparation of lime nitrogen: Mix industrial solid waste calcium carbonate with urea and grind it, and then calcined at 300°C for 3 hours under the protection of nitrogen, then heat up to 650°C and continue calcining for 3 hours. After the reaction, cool to room temperature under nitrogen atmosphere, and the obtained Lime nitrogen crude product is ground, standby;

[0033] (2) Calcium carbonate recovery: In the case of continuous introduction of carbon dioxide into the water, the lime nitrogen prepared in ...

Embodiment 3

[0041] A clean preparation method for an aqueous solution of cyanamide, using calcium carbonate solid waste produced in the industrial production of cyanamide as a raw material, reacting with urea at high temperature to prepare lime nitrogen, and then preparing an aqueous solution of cyanamide under the action of water and carbon dioxide, At the same time, the recovery, recycling and reuse of calcium carbonate are realized.

[0042] Include the following steps:

[0043] (1) Preparation of lime nitrogen: Mix industrial solid waste calcium carbonate with urea and grind it, and then calcined at 400°C for 4 hours under the protection of nitrogen, then heat up to 850°C and continue calcining for 2 hours. After the reaction, cool to room temperature under nitrogen atmosphere, and the obtained Lime nitrogen crude product is ground, standby;

[0044] (2) Calcium carbonate recovery: In the case of continuous introduction of carbon dioxide into the water, the lime nitrogen prepared in ...

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PUM

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Abstract

The invention belongs to the field of chemical industry, and particularly relates to a clean preparation method of an aqueous cyanamide solution. Calcium carbonate solid waste produced in the industrial production of cyanamide is used as a raw material, and reacts with urea at a high temperature to prepare lime nitrogen, the aqueous cyanamide solution is prepared from the lime nitrogen under the action of water and carbon dioxide, and the recovery, recycling and reuse of calcium carbonate are realized. The production method of the aqueous cyanamide solution, designed in the invention, has theadvantages of high yield, low cost, and no production of three wastes in the production process, and is a green way with economic environmental benefits.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a method for cleaning and preparing an aqueous solution of cyanamide. 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] Cyanamide solution is used abroad as a defoliant and non-toxic insecticide for fruit trees. Crystalline cyanamide is mainly used in the synthesis of medicines,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01C3/16
CPCC01C3/16
Inventor 于龙张超梁万根刘军张宁安敬瑞高鹏
Owner SHANDONG EFIRM BIOCHEMISTRY & ENVIRONMENTAL PROTECTION CO LTD
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