Method of preparing cyanamide aqueous solution and dicyandiamide and coproducing carbon and calcium carbonate by calcium cyanamide

Abstract

The invention discloses a manufacturing method of mono-cyandiamide solution and di-cyandiamide and joint carbon and calcium carbonate, which comprises the following steps: adding limestone nitrogen into 3%-30% mono-cogeneration solution; stirring until reacting completely under 60 deg.c; separating insoluble matter to obtain carbon; making the effective nitrogen molar rate of mono-cogeneration and limestone nitrogen in the mono-cogeneration solution more than 1; aerating carbon dioxide into filtrate; evolving calcium carbonate with pH value below 10 under 60 deg.c; proceeding binary polymerization for mono-cogeneration to make di-cogeneration with high dissolving efficiency.

Description

technical field

[0001] The invention relates to a production method of cyandiamide aqueous solution and dicyandiamide, in particular to a method for producing cyandiamide aqueous solution, dicyandiamide and co-production of carbon and calcium carbonate with lime nitrogen. Background technique

[0002] Cyanamide and dicyandiamide are widely used as industrial raw materials in the pesticide and pharmaceutical raw material industries, and are used as epoxy resin curing agents, dye fixing agents, flocculants, etc. Crystalline cyanamide is mainly used in the synthesis of medicines, health care products, feed additives and pesticide intermediates. The aqueous solution of cyanamide can be used as a defoliant and non-toxic insecticide for fruit trees. Dicyandiamide can be used to manufacture drugs such as guanidine salt, sulfadiazine, barbituric acid, and virus spirit; it can also be used as an organic chemical raw material in the plastics industry to produce melamine, formaldehyde ...

Images