Liquid fertilizer from batchwise ammoniation of wet-process phosphoric acid

Claim 1

IN A PROCESS FOR THE PRODUCTION OF FERTILIZER FROM 3THEREOF COMPRISING THE STEPS OF ADJUSTING THE CONCENTRAWET-PROCESS PHOSPHORIC ACID AND THE BATCH AMMONIATION TION OF SAID WET-PROCESS PHOSPHORIC ACID TO THE RANGE OF ABOUT 20 TO 28 PERCENT P2O5; INTRODUCING AMMONIA INTO SAID ACID; RISING THE TEMPERATUR OF THE ACID SOLUTION TO ABOUT ITS BOILING POINT BEFORE RAPID PRECIPITATION OF CONGENERIC IMPURITIES IN SAID WET-PROCESS PHOSPHORIC ACID OCCURS; DICONTINUING INTRODUCTION OF AMMONIA WHEN THE PH OF THE RESULTING SUSPENSION IS IN THE RANGE FROM ABOUT 6.0 TO 6.6; AND SEPARATING THE RESULTING EASILY SEPARABLE PRECIPITATE FROM THE SOLUTION WITHOUT STRONG AGITATION, THE IMPROVEMENT THEREIN WHICH COMPRISES INTRODUCING SAID AMMONIA TO SAID ACID AT A RELATIVELY HIGH RATE IN THE RANGE FROM ABOUT 15 POUNDS TO ABOUT 50 POUNDS OF AMMONIA PER HOUR PER CUBIC FOOT OF AACID SOLUTION UNTIL THE PH OF SAID ACID IS ABOUT 2.8; SUBSEQUENTLY INTRODUCING AMMONIA INTO SAID ACID AT A RELATIVELY LOW RATE IN A RANGE FROM ABOUT 2 POUNDS TO ABOUT 5 POUNDS PER HOUR PER CUBIC FOOT OF ACID SOLUTION UNTIL THE PH OF THE ACID REACHES ABOUT 4.2, SAID INTRODUCTION OF AMMONIA AT SAID RELATIVELY LOW RATE CAUSING THE FORMATION OF A GRANULAR EASILY SEPARABLE PRECIPITATE, WHICH PRECIPITATE IS SEPARATED FROM SAID ACID SOLUTION IN A LATER-MENTIONED SEPARATED STEP; SUBSEQUENTLY ADDING THE REMAINING AMMONIA AT A RELATIVELY HIGH RATE IN THE RANGE FROM ABOUT 15 POUNDS TO ABOUT 50 POUNDS OF AMMONNNIA PER HOUR PER CUBIC FOOT OF ACID SOLUTION TO SAID ACID SOLUTION DURING THE FINAL ADJUSTMENT OF PH FROM ABOUT 4.2 TO THE RANGE OF ABOUT 6.0 TO 6.6; AND SUBSEQUENTLY SEPARATING THE RESULTING GRANULAR, EASILY SEPARABLE PRECIPITATE FROM SAID ACID SOLUTION, SAID SOLUTION, AFTER REMOVAL OF SAID PRECIPITATE, BEING THE CLEAR LIQUID FERTILIZER PRODUCT.