METHOD OF PRODUCING COMPLEX NITROGEN FERTILIZER WITH PROLONGED ACTION Russian patent published in 2024 - IPC C05C9/02 

FIELD: fertilizers.

SUBSTANCE: invention relates to methods of producing complex nitrogen fertilizers comprising microelements, used in various soil and climatic conditions for a variety of agricultural crops. The method of producing fertilizer is based on the condensation of urea with a formaldehyde-containing composition in an aqueous medium, neutralization of the resulting suspension by adding a deoxidizer, followed by filtering the precipitate and drying it, as well as returning the aqueous filtrate to prepare the original urea solution. A mixture of urea-formaldehyde concentrate KFK-85 with orthophosphoric acid with pH 2.6÷ 3.0 is used as a formaldehyde-containing composition. Condensation is carried out at a temperature of 40± 2°C. The neutralizer for the resulting suspension is dolomite flour or technical aqueous ammonia grade B.

EFFECT: possibility of obtaining a complex long-acting methylene urea fertilizer for fertilizing agricultural crops using a waste-free method.

1 cl, 3 ex