METHOD FOR PRODUCTION OF AMMONIUM-PHOSPHATE-SULFATE Russian patent published in 2010 - IPC C05G1/06 

FIELD: agriculture.

SUBSTANCE: method includes neutralisation of phosphoric and sulfuric acids by ammonium with separate supply of acids, separation of steam from pulp, granulation and drying of finished product. Phosphoric acid is extraction phosphoric acid with concentration of 32-40% P₂O₅. Acids are neutralised with ammonium serially in three stages. At the first stage phosphoric acid is mixed with absorption liquid from stage of effluent gases treatment from ammoniator-granulator and drying drum, to achieve density of mixture of 1.35-1.45 t/m³, and neutralised to produce reaction mass with mole ratio of NH₃/H₃PO₄, equal to 0.2-0.5. At the second stage reaction mass and sulfuric acid are neutralized in tubular reactor to produce ammonium-phosphate-sulfate with mole ratio of NH₃/H₃PO₄, equal to 0.8-0.9. At the third stage pulp is additionally neutralised in ammoniator - granulator.

EFFECT: invention makes it possible to expand assortment of fertilisers, which contain nitrogen in ammonium form and considerable amount of sulfate sulfur, to increase reliability of process equipment operation and efficiency of plant.

2 cl, 1 dwg, 1 tbl, 6 ex