PRODUCTION OF AQUEOUS SOLUTION OF CALCIUM DICYANAMIDE

摘要

PURPOSE:To obtain an aqueous solution of calcium dicyanamide having stable purity, by adding calcium hypochlorite to a reaction product of calcium cyanamide and cyanogen chloride and heat-treating the mixture. CONSTITUTION:An aqueous solution of crude calcium dicyanamide is produced by reacting calcium cyanamide with cyanogen chloride in an aqueous solvent. Since the obtained crude solution is usually alkaline, it is adjusted to 4-8 pH with an acidic substance. The pH-adjusted solution is added with calcium hypochlorite and heat-treated to obtain the objective aqueous solution. The acidic substance is preferably hydrochloric acid. The pH of the aqueous solution should be kept within 4-8 to prevent the decomposition of calcium dicyanamide. The heat-treatment is carried out at 50-90 deg.C usually for 1-8hr. Too long heat-treatment is undesirable because it causes decomposition of calcium dicyanamide.