Methods Of Manufacture Of Cyanuric Acid

The main methods of producing cyanuric acid are urea pyrolysis and semi-cyclic method.

(1) Urea pyrolysis method: Urea pyrolysis of the ring.
According to the different pyrolysis methods, solid phase melting and liquid phase method are divided. The solid phase method will heat the urea to 200~300℃, pyrolysis get the crude cyanuric acid, then add 15~20% sulfuric acid (or nitric acid, hydrochloric acid), cooking, after filtration, washing, drying to get the finished product. This is the main method of industrial production of cyanuric acid. Industrial Purity ≥95%, urea 1200kg per ton of products. The liquid phase method is in aromatic hydrocarbon or mineral oil solvent, the reaction completes, the separation solvent, washes, dries obtains the finished product, the reaction condition is relaxed, the corrosion is small, but the recovery rate is low.

(2) Half-circulation method: The cyanuric acid powder into the ball disk, in the gradual addition of urea, its molar ratio for 1.7~2, heating up to 190 ℃, continue for half an hour, stop heating, continue to roll until no ammonia generation. The small part is removed, crushed, sulfuric acid dissolved, boiled, centrifugal filtration, washing and drying to get the finished product. The remainder continues to circulate the ball.