High-analysis ammonium polyphosphate fertilizer

Claim 1

A PROCESS FOR PRODUCING A SOLID, HIGH-ANALYSIS AMMONIUM POLYPHOSPHATE FERTILIZER MATERIAL CONTAINING ABOUT 80 PERCENT AVAILABLE PLANT NUTRIENTS (N+P2O5) FROM ANHYDROUS AMMONIA AND SUPERPHOSPHORIC ACID, WHICH COMPRISES MAINTAINING IN A CLOSED REACTION VESSEL AT A TEMPERATURE IN THE RANGE FROM ABOUT 325*F. TO ABOUT 475*F. AND UNDER A CONSTANT PRESSURE IN THE RANGE FROM ABOUT 10 P.S.I.G. TO ABOUT 1000 P.S.I.G., A MASS OF MOLTEN MATERIAL OF LOW VISCOSITY, PREVIOUSLY FORMED BY COMBINING ANHYDROUS AMMONIA AND SUPERPHOSPHORIC ACID THEREIN, SAID SUPERPHOSPHORIC ACID CONTAINING IN THE RANGE FROM ABOUT 74 PERCENT P2O5 TO ABOUT 85 PERCENT P2O5 BY WEIGHT; CONTINUOUSLY COMBINING RELATIVELY SMALL STREAMS OF SAID ANHYDROUS AMMONIA AND SAID SUPERPHOSPHORIC ACID INTO SAID MASS OF MOLTEN MATERIAL; CONTINUOUSLY VIGOROUSLY AGITATING SAID MASS OF MOLTEN MATERIAL, THEREBY KEEPING SUBSTANTIALLY THE ENTIRE MASS THEREOF WELL AGIATED AND CAUSING IMMEDIATE AMMONIATION OF THE INFLOWING SUPERPHOSPHORIC ACID; AND WITHDRAWING FROM THE BOTTOM OF SAID MASS OF MOLTEN MATERIAL MOLTEN AMMONIUM POLYPHOSPHATE AS PRODUCT.