Study of the urea hydrolysis kinetics in the precipitation conditions of hydroxides and metal salts

The results of studies of the urea hydrolysis kinetics in the temperature conditions corresponding to the precipitation conditions of hydroxides and metal salts were presented. The research was carried out at temperatures of 80-100 °C. The process mechanism was determined - the first-order reaction takes place, the kinetic equation of the urea hydrolysis process was obtained, the dependence of the reaction rate on temperature was defined. The activation energy - 88 kJ, indicating the process flow in the kinetic region was calculated. The rates of accumulation of the hydrolysis products - ammonia and carbon dioxide, which are precipitators of hydroxides and metal salts, in the solution were experimentally studied. It was found that in the hydrolysis process, the amount of ammonia and carbon dioxide in the solution decreases.  The temperature at which the there is the highest amount of hydrolysis products in the solution is 90 °C.