Manufacture of granular fertilizers

Claim 1

A CONTINUOUS PROCESS FOR THE PRODUCTION OF A MULTILAYERED GRANULAR AMMONIUM PHOSPHATE FERTILIZER OF AN N:P RATIO BETWEEN 1.4 AND 2.2, WHICH COMPRISES PROVIDING QUANTITIES OF PHOSPHORIC ACID AND AMMONIA, REACTING SAID QUANTITIES OF PHOSPHORIC ACID AND AMMONIA ON GRANULES OF AMMONIUM PHOSPHATE IN A FIRST REGION OF A REACTION CHAMBER WHILE MAINTAINING THE PARTIAL PRESSURE OF THE AMMONIA THEREIN AT A LEVEL HIGHER THAN THE AMMONIA PRESSURE GENERATED BY ANY DECOMPOSITION OF SAID AMMONIUM PHOSPHATE GRANULES, PASSING SAID GRANULES TO A SECOND REGION IN SAID RECTION CHAMBER AND TREATING SAME THEREIN WITH A CURRENT OF AIR OF A VOLUME SUFFICIENT TO REMOVE ANY WATER VAPORIZED AND CARRIED OVER FROM SAID FIRST REGION AND INSUFFICIENT TO REMOVE ANY SIGNIFICANT QUANTITY OF AMMONIA THEREBY MAINTAINING THE MOISTURE CONTENT OF SAID GRANULES AT A LEVEL BELOW ABOUT 1% AND FORMING A LAYER OF AMMONIUM PHOAPHATE ON EACH OF SAID GRANULES, WITHDRAWING SAID GRANULES FROM SAID SECOND REGION OF SAID REACTION CHAMBER, REMOVING A PORTION OF SAID GRANULES FROM SAID SECOND REGION AND IN AN AMOUNT SUBSTANTIALLY EQUIVALENT TO THE ACID AND AMMONIA BEING ADED TO SAID CHAMBER, RECIRCULATING THE REMAINDER OF SAID GRANULES TO SAID FIRST REGION INSIDE THE CHAMBER WHILE MAINTAINING THE MOISTURE CONTENT OF THE SAME OF LEVEL BELOW 1%, THE RATIO OF THE RATE OF RECIRCULATION TO THE RATE OF REMOVAL BEING AT LEAST