Method and apparatus for use in the manufacture of mixed fertilizer

Claim 1

IN THE MANUFACTURE OF A MIXED FERTILIZER USING AMMONIA-AMMONIUM NITRATE SOLUTION AS THE SOURCE OF NITROGEN, THE PROCESS COMPRISING FORMING A STREAM OF FERTILIZER SOLIDS FLOWING THROUGH A REACTION ZONE, PASSING A FLOW OF AIR IN SAID ZONE COUNTER-CURRENT TO SAID STREAM OF SOLIDS, INTRODUCING A CONCENTRATED MINERAL ACID SELECTED FROM THE GROUP CONSISTING OF SULPHURIC ACID AND PHOSPHORIC ACID INTO SAID STREAM AT AN UPSTREAM POINT IN SAID ZONE, AND INTRODUCING AMMONIA-AMMONIUM NITRATE SOLUTION INTO SAID STREAM AT A POINT DOWNSTREAM OF THE INTRODUCTION OF SAID ACID, WHEREBY A PORTION OF THE AMMONIA OF SAID SOLUTION WILL BE VAPORIZED DOWNSTREAM AND THE VAPORS CARRIED UPSTREAM BY SAID COUNTERCURRENT FLOW OF AIR TO PARTIALLY NEUTRALIZE SAID ACID MOVING IN SAID STREAM TO FORM AN ACID SALT AND TO HEAT THE SOLIDS FOR THE VAPORIZATION OF AMMONIA AT SAID DOWNSTREAM POINT, AND SAID ACID SALT WILL MOVE DOWNSTREAM AND AGGLOMERATE SAID SOLIDS AND REACT WITH ANOTHER PORTION OF AMMONIA FROM SAID SOLUTION TO COMPLETELY NEUTRALIZE THE ACID SALT TO PRODUCE A NORMAL AMMONIUM SALT.