Verfahren zur Herstellung eines Ammoniumsulfat und Harnstoff enthaltenden Düngemittels

摘要

The invention relates to a method for producing a fertilizer containing ammonium sulfate and urea. According to the invention, an aqueous urea solution is provided which, with regard to the total weight of the solution, contains 0.1 to 50 wt. % of free ammonia and/or of ammonia that is bound in the form of ammonium carbamate. Said aqueous urea solution is reacted with sulfuric acid and, optionally, with ammonia at a temperature ranging from 25 to 250 DEG C and at a pressure ranging from 0.1 to 250 bar in order to form a urea-ammonium sulfate solution or suspension in quantities that result in a weight ratio of ammonium sulfate to urea in this urea-ammonium sulfate solution or suspension that ranges from 10: 90 up to 65: 35, whereby CO2 and ammonia expelled under these conditions are returned to the urea synthesis. Afterwards, this urea-ammonium sulfate solution or suspension is subjected to a subsequent processing in order to produce solid or liquid fertilizers. According to a second aspect, the invention relates to urea-ammonium sulfate granulates or prills, which can be produced according to said method and which have excellent properties with regard to application techniques.