Process for preparing cyanuric acid

The present invention belongs to the technical field of the preparation of intermediates organic chemicals, specifically speaking discloses a method for preparing cyanuric acid. The preparation method comprising preparing, hydrolysis and washing step three crude cyanuric acid. Wherein the hydrolysis step is: three pumps were used to heat the reaction tube after the urea cyanurate obtained crude, saturated steam and hot sulfuric acid is continuously supplied to the reaction column by at least two communicating via a first conduit in the reaction column; simultaneously controlling the flow rate of sulfuric acid, the sulfuric acid concentration after cooling, the crude cyanuric acid flow, and the reaction was washed with water and separated cyanide acid. Since the preparation of cyanuric acid hydrolysis step, using a continuous hydrolysis process tower, so that the hydrolysis step can be continuously performed at high temperature and high pressure, which accelerates the reaction rate. Thus, this process has a short reaction period, the operation is simple, easy control of product quality advantage and improved production efficiency.