| 摘要 |
The invention concerns a method for incorporating micronutrients in an outer shell of urea-based particles, characterized in that it comprises the steps of a) applying a liquid concentrated mineral acid with a water content of at most 25 weight% to urea-based particles having a water content of at most 2 weight%, in order to at least form a double salt layer at the outer surface of the urea-based particles such that an acidified particle grasping layer is obtained, and subsequently b) applying a solid mineral base in powder form to the urea-based particles of step a) in order to react with the grasping layer of the urea-based particles; wherein the mineral acid or the solid mineral base are the source of any one of the micronutrients and wherein the liquid concentrated mineral acid and the solid mineral base in powder form are applied in a non-equimolar ratio between 0.1 and 1 mol/mol mineral acid / mineral base. The invention furthermore concerns a particulate urea-based fertilizer, comprising urea-based particles with a water content of at most 2 weight%, comprising micronutrients in an outer shell, the urea-based particles being obtained by a method according to the invention. |
