METHOD FOR PREPARING NITROGEN-POTASSIUM-SULFATE FERTILIZER Russian patent published in 2003 - IPC

FIELD: fertilizers. SUBSTANCE: invention relates to chemical technology for preparing granulated complex mineral fertilizers. Method for preparing nitrogen-potassium-sulfate fertilizers involves mixing carbamide with potassium- and sulfate-containing component, thermal treatment of mixture, granulating fertilizers by cooling the melt and grinding the prepared crystallizate. Mixing carbamide is carried out with anhydrous powder-liked potassium sulfate, thermal treatment of mixture is carried out for a single stage by heating up to carbamide melting point in mixture and cooling the melt up to onset moment of crystallization is carried out at the rate 10-30 degreed/ min. Potassium sulfated is added in the amount 10-75% and carbamide, the balance. Cyclone dust of potassium sulfate formed in drying potassium sulfate is used as powder-liked potassium sulfate. Invention provides simplifying technology, reducing number of stages and nitrogen loss. Invention can be used in plants producing complex fertilizers based on carbamide (urea). EFFECT: improved preparing method. 3 cl, 1 tbl