Process for the preparation of magnesium ammonium phosphate

Claim 1

A FULLY CONTINUOUS PROCESS FOR PREPARING A NONBURNING GRANULAR FERTILIZER COMPRISING FERTILIZER GRADE MAGNESIUM AMMONIUM PHOSPHATE ANALYZING ABOUT 7-9% NITROGEN, AS N, AND ABOUT 42-45% P2O5, SAID PROCESS COMPRISING; (A) REACTING AMMONIA, MAGNESIUM KHYDROXIDE, AND PHOSPHORIC ACID SOLUTION ANALYZING ABOUT 40-58% P2O5 IN THE MOLE RATIO OF NH3:MG(OH)2:H3PO4 OF ABOUT 1-1.1:1:1 TO FORM MAGNESIUM AMMONIUM PHOSPHATE AND GRANULATING THE RESULTANT PRODUCT IN A REACTOR-GRANULATOR; (B) DRYING THE RESULTING GRANULES IN A DRYING UNIT; (C) SCREENING THE THUS DRIED GRANULES IN A CREENING DEVICE AND RECOVERING, (1) THOSE GRANULES PASSING A 3 MESH SCREEN AND RETAINED ON A 6 MESH SCREEN, AND (2) THOSE GRANULES PASSING A 6 MESH SCREEN, AND RETAINED ON A 16 MESH SCREEN, THE RECOVERED GRANULES COMPRISING FERTILIZER GRADE MAGNESIUM AMMONIUM PHOSPHATE ANALYZING ABUT 7-9% NITROGEN, AS N, AND ABOUT 42-45% P2O5; (D) RECYCLING THE FINE, -16MESH, GRANULES TO THE REACTOR-GRANULATOR; (E) CRUSHING THE OVERIZE, +3 MESH, GRANULES AND RECYCLING THE CRUSHED PARTICLES TO SAID SCREENILNG DEVICE; (F) SIMULANEOUSLY PASSING AIR FROM THE DRYING AND COOLING UNITS THROUGH DUST COLLECTORS AND RECYCLING THE COLLECTED DUST TO THE REACTOR-GRANULATOR; (G) SIMULTANEOUSLY PASSING EXHAUST AIR FROM THE REACTOR-GRANULATOR AND THE DUST COLLECTORS THROUGH A WATER SCRUBBING TOWER, WHEREBY AMMONIA VAPOR IN SAID AIR IS ABSORFED IN WATER; AND (H) SIMULATANEOUSLY RECYCLING THE THUS JABSORBED AMMONIA TO THE REACTOR-GRANULATOR.