High analysis ammonium pyrophosphate process and product

Claim 1

A PROCESS FOR THE PRODUCTION OF REAGENT GRADE AMMONIUM PYROPHOSPHATE FROM ANHYDROUS AMMONIA AND HIGHLY CONCENTRATED PHOSPHORIC ACID, WHICH PROCESS COMPRISES THE STEPS OF MAINTAINING IN A CLOSED REACTION VESSEL AT A TEMPERATURE IN THE RANGE FROM ABOUT 300*F. TO ABOUT 500*F. AND UNDER A CONSTANT POSITIVE PRESSURE IN THE RANGE FROM ABOUT 10 P.S.I.G. TO ABOUT 1000 P.S.I.G. A MASS OF MOLEN MATERIAL OF LOW VISCOSITY PREVIOUSLY FORMED BY COMBINING IN SAID CLOSED REACTION VESSEL SAID ANHYDROUS AMMONNIA WITH SAID HIGHLY CONCENTRATED PHOSPHORIC ACID, SAID HIGHLY CONCENTRATED PHOSPHORIC ACID CONTAINING IN THE RANGE FROM ABOUT 78 PERCENT BY WEIGHT P2O5 TO ABOUT 80 PERCENT BY WEIGHT P2O5; CONTINUOUSLY COMBINING RELATIVELY SMALL STREAMS OF SAID ANHYDROUS AMMONIA AND SAID HIGHLY CONCENTRATED PHOSPHORIC ACID INTO SAID MASS; CONTINUOUSLY VIGOROUSLY AGITATING SAID MASS THEREBY KEEPING SUBSTANTIALLY THE ENTIRE MASS WELL AGITATED AND EFFECTING IMMEDIATE AMMONIATION OF SAID INFLOWING ACID; WITHDRAWING FROM THE BOTTOM OF SAID MASS SURPLUS MOLTEN AMMONIUM PHOSPHATE MATERIAL; COMBINING SAID WITHDRAWN AMMONIUM POLYPHOSPHATE MATERIAL WITH AQUEOUS MEDIUM TO FORM A SLURRY THEREWITH; SUBSEQUENTLY ADJUSTING THE PH OF SAID SLURRY BY THE AMMONIATION THEREOF TO A FINAL PH IN THE RANGE FROM 5.0 TO 6.3 THEREBY EFFECTING A RECRYSTALLIZATION OF THE DIAMMONIUM PYROPHOSPHATE PHATE PHASE TO THE TRIAMMONIUM PYROPHOSPHATE MONOHYDRATE IN THE FORM OF EASILY FILTRABLE CRYSTALS THEREOF; AND SEPARATING SAID CRYSTALS OF TRIAMMONIUM PYROPHOSPHATE MONOHYDRATE AS PRODUCT.