Method for making nitrogenous and complex fertilizers in highly homogenized spherical granule form starting from urea-formaldehyde liquid resins and the fertilizer made thereby

摘要

The present invention relates to a method for making nitrogenous and complex fertilizers, in granule form, suitable for slowly releasing nitrogen, comprising the steps of preparing an aqueous urea/formaldehyde dispersion with a molar ratio from 0.8:1 to 2:1, adding an aqueous catalyzer solution in a weight ratio from 0.1 to 4%, controlling the pH of the aqueous dispersion to hold it within a range from 4.0 to 7.0, and supplying the aqueous dispersion to a recirculating granulating device, as a growth seed. IMAGE