METHOD FOR OBTAINING SLOW-RELEASE FERTILIZER Russian patent published in 2021 - IPC C05C9/02 

FIELD: fertilizer production.

SUBSTANCE: invention relates to methods for obtaining slow-acting urea-formaldehyde fertilizers used in various soil and climatic conditions for a variety of agricultural crops. The method for obtaining a slow-release fertilizer is based on the condensation of carbamide with a methyl-urea composition in an aqueous medium in the presence of phosphoric acid, neutralization of the resulting suspension to pH (7±0.3) by adding a deoxidizer, followed by filtration of the sediment and drying it, as well as the return of an aqueous filtrate to prepare the initial urea solution, and the carbamide-formaldehyde concentrate KFK (CFC)-85 is used as a methyl-urea composition.

EFFECT: proposed method for obtaining a slow-release urea-formaldehyde fertilizer provides a reduction in energy costs for the production of the fertilizer, accelerates the process of fertilizer synthesis, provides obtaining a fertilizer with a delayed release of nitrogen for fertilizing crops, which prevents the ingress of bound nitrogen into reservoirs.

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