反应详情

A method of manufacturing water soluble mixed NPK fertilizer composition in solid form comprising the steps of (a) dissolving urea in phosphoric acid to form a urea phosphoric acid adduct solution, (b) adding one or more potassium salts to said adduct while agitating to form a mixture in solid or slurry form and (c) cooling the mixture thus formed, so as to crystallize the solid soluble fertilizer granules when the mixture is a slurry, the constituents of the mixture so chosen that the final product contains between 5 and 42% nitrogen, between 2 and 15% phosphorus and between 1 and 38% potassium, these values being elemental mass as a percentage relating to the total mass of the composition, the resulting composition, in 10% aqueous solution, having a pH of between 1.2 and 2.0.