Improvements in or relating to the manufacture of cyanuric acid

Cyanuric acid is prepared by heating a mixture of urea and an ether-alcohol of formula H(CH2)m (OCH2,CH2)nOH, where m = 0, n = 1 -17, and m + n = 2 or more, to liberate ammonia and form a homogeneous solution and further heating the solution at 200 DEG -250 DEG C. to precipitate cyanuric acid, which is separated. The homogeneous solution is stated to be a "carbamate" of the ether-alcohol, which may be one or more of the methy, ethyl, propyl, butyl, or hexyl mono-ethers of mono-, di-, tri-, or polyethylene glycols, or di-, tri-, or poly-ethylene glycols. The further heating of the homogeneous solution at 200 DEG - 250 DEG C., with further NH3 evolution may be after the addition of further urea if such addition is necessary to ensure a total content of more than 1 mole of urea, per mole of ether-alcohol. The cyanuric acid is separated by adding a solvent for the "carbamate", e.g. primary alcohols of 1 - 3 C atoms, such as methanol. Repeated addition of urea to the mother liquor from the separation permits continuous operation.