METHOD FOR PREPARING COMPLEX NITROGEN-PHOSPHORUS FERTILIZER Russian patent published in 2004 - IPC

FIELD: fertilizers. SUBSTANCE: invention relates to method for preparing complex solid granulated mineral fertilizers based on ammonium nitrate and phosphoric acid. Method involves ammonization of cleared superphosphoric acid in the presence of corrosion inhibitors to obtain ammonium phosphate, for example, liquid complex fertilizer. Prepared solution is heated to temperature 70-80 C and mixed with ammonium nitrate solution with concentration 89-92% and then evaporation and granulation of prepared mixture is carried out followed by treatment of granules with anti-caking substance. Method provides preparing nitrogen-phosphorus fertilizer with nitrogen content 31-33%, phosphorus content 5-7% as measured for P₂O₅ and low moisture content. Method is carried out on the basis of working equipment for producing ammonium nitrate by increasing working life of equipments and pipelines. EFFECT: improved preparing method. 2 cl, 1 ex