PROCESS FOR MANUFACTURE OF GRANULAR SLOW-ACTING FERTILIZER Russian patent published in 1994 - IPC

FIELD: chemistry. SUBSTANCE: this process for manufacturing granular slow-acting fertilizer prescribes introducing mineral additive, which is mixture including 0.5 to 5.0 mass percent ammonium sulfate, 0.3 to 2.0 mass percent magnesium-containing component (these figures are stated in terms of MgO) and 0.1 to 0.3 mass percent iron-containing component (these figures are given in terms of iron oxide) into starting melt. Disclosed process further prescribes using caustic magnesite or magnesium nitrate as magnesium-containing component and iron oxide or iron sulfate as iron-containing component. EFFECT: higher yield of fertilizer granules having no shrinkage bores, lower rate of consumption of encapsulating agent and higher durability of granules. 3 cl, 4 tbl