Method for purifying cyanamide

Abstract

The invention relates to a method for purifying cyanamide, which comprises the following steps: with a cyanamide crude product as a raw material, carrying out reduced-pressure distillation in a reaction kettle under the conditions that the vacuum degree is 0.07-0.09 MPa and the temperature is 30-50 DEG C for 2-4 hours; taking a residual product in the reaction kettle after distillation, and conducting recrystallizing with an organic solvent and a stabilizer under the condition that the temperature is -8 DEG C to -20 DEG C; and filtering the crystal obtained by recrystallization, and conductingdrying to remove the organic solvent, so as to obtain the cyanamide crystal with a purity of 99.0% or above. By adopting the method, most of water in the raw material is removed by utilizing a reduced-pressure distillation method, and the polymerization and decomposition of the cyanamide can be prevented by controlling the temperature within 50 DEG C; residual water in the product can be removedat a low temperature by using an organic solvent capable of being mixed with water, and the organic solvent can be recycled; and by adding the stabilizer, polymerization and decomposition reactions ofthe cyanamide in the purification process can be inhibited, and the purity of the cyanamide is effectively improved.

Description

technical field [0001] The invention relates to a method for purifying 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] For example, a "preparation method of a solid cyanamide" disclosed in the Chinese patent literature, its announcement number CN107473241A, the method uses lime nitrogen as a raw material to prepare cyanamide in an organic solvent under the action of carbon ...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the problem in the prior art that cyanamide is easy to polymerize and decompose during the purification process resulting in insufficient product purity, the present invention provides a cyanamide capable of stable crystallization and a product purity of up to 99%. purification method