METHOD OF PREPARING COMPOUNDED GRANULAR PHOSPHORUS CONTAINING FERTILIZERS Russian patent published in 1998 - IPC

FIELD: agriculture. SUBSTANCE: claimed method comprises mixing phosphorus-containing component with nitrogen-containing additive and subsequently granulating mixture at elevated temperature. Phosphorus-containing component is mixed with nitrogen- containing component solution to attain N: P₂O₅: H₂O ratio of 1:(0.04-0.7):(0.1-8.9) at 70-105 C, and the resulting suspension is granulated. It is desirable to use ammonium and/or calcium phosphates, phosphites as phosphorus-containing component, and to use ammonium nitrate and/or sulfate, and carbamide as nitrogen- containing component. During mixing operation, potassium-containing additive is also added. Suspension is granulated at 60-90 C. The claimed method makes it possible to produce wide range of fertilizers with high yield of commercial fraction up to 70-85%. EFFECT: improved properties of the fertilizers. 4 cl, 5 ex