Apparatus and process for coating particles

摘要

An apparatus and method for continuously producing polymer coated particles, and in particular, a polymer coated fertilizer, wherein the coating material used is, for example, an aqueous film forming latex. The coating process is conducted with a plurality of fluidized beds, connected in series, under conditions such that, preferably, the relative humidity of the air in the initial coating zones is maintained below the critical relative humidity of the particle to be coated. The apparatus and process provides a method to prepare coated particles having a narrow coating weight distribution, and thus allows for the economical production of a slow release fertilizer.