PROCESS FOR CONCENTRATING AN ALREADY CONCENTRATED UREA SOLUTION TO FORM A PRACTICALLY ANHYDROUS MELT

摘要

Process for concentrating a partly concentrated urea solution to form a substantially anhydrous melt, which urea solution is obtained by evaporation under vacuum or by melting moist urea crystals and which urea solution contains at least 98 percent by weight of urea, by allowing the solution to expand to a pressure between 0.013 and 0.067 bar and removing the water vapour released thereby.