METHOD FOR PRODUCING PHOSPHORIC FERTILIZER

摘要

The invention relates to manufacture of phosphoric fertilizers widely used in agriculture. A method of producing phosphoric fertilizer comprises mixing phosphoric acid heated to 75-85°C of concentration 48-50% POwith calcium-containing feedstock and a recycle in a mixer, granulation and mixture ripening, drying to residual moisture of 1-3% and product classification, wherein defecate with 4-15% moisture is used as the calcium-containing feedstock, absorption solutions are introduced in the mixer maintaining the ratio of the absorption solution consumption to the defecate within 0.15-0.30, and the mixing is carried out to mass ratio CaO/POin the mixture within (0.45-0.88):1. The method provides to manufacture phosphoric fertilizer of prolonged action, as well as to regulate content of citric-soluble and water-soluble phosphate and their ratio in the product with minimum presence of free acidity (less than 1.0%).