The oleoresin methylene urea product used as a fertilizer is prepared according to the following steps: a) The aqueous base of urea and dehalaldehyde, from which the total molar ratio of urea to dehalaldehyde (1: 1) to (1: 2) is introduced into the first reactor. The residence time in the reactor is approximately half an hour. The temperature is maintained between 40 and 95 řC and the pH is maintained between 6.5 and 11 to obtain a methyleneurea compound, (b) the methyleneurea is transferred to a secondary reactor at a temperature between 5 and 35 C, pH and between 1.8 and 3.5, to obtain a primary alumina methylene urea sludge and, if appropriate, (c) a methylene urea compound or a primary alumina methylene urea slurry is transferred to a third reactor at a temperature of 5 and 35 ° C. and a pH of between 1.8 and 3.5, to obtain a second-order low-alumina methylene urea slurry; (e) the filtrate is recycled to the reactor for reprocessing and and (f) neutralizing and drying the precipitated methylene urea precipitate and then recovering it as the above-mentioned methylene urea product. ŕ
展开▼
