Process for the preparation of a granular NPK fertilizer and granular NPK fertilizers obtained by this process

摘要

Storage-stable nitrogen-phosphorous-potassium fertilizer granules and prills are made by adding to a molten or aqueous solution mixture of ammonium nitrate and ammonium phosphate, a particulate potassium salt, typically potassium chloride, in which the particles have an average size no greater than 55 microns and less than 1% by weight of the particles are larger than 150 microns. The potassium salt is added without the need for preheating and at a temperature of between 5 DEG and 40 DEG C. to the mixture where it is simultaneously converted. The resulting mixture is granulated or prilled into NPK fertilizer particles.