Fertilizer process comprising two-stage ammoniation with counter current gas treatment

Claim 1

A PROCESS FOR THE MANUFACTURE OF AMMONIUM SALTS CONTAINING LESS THAN 5% BY WEIGHT OF WATER WHICH COMPRISES, IN A FIRST STAGE, FORMING A MIXTURE OF AMMONIUM SALT AND ACID, SAID MIXTURE BEING SELECTED FROM THE GROUP CONSISTING OF (A) A MIXTURE OF NITRIC ACID AND ITS AMMONIUM SALT HAVING A PH IN THE RANGE 3.5 TO 4.5 (B) A MIXTURE OF SULPHURIC ACID AND NITRIC ACID AND THEIR AMMONIUM SALTS HAVING A PH IN THE RANGE 2.0 TO 3.0, AND (C) A MIXTURE CONTAINING AT LEAST TWO COMPOUNDS SELECTED FROM THE GROUP CONSISTING OF NITRIC ACID, PHOSPHORIC ACID, AMMONIUM NITRATE AND AMMONIUM PHOSPHATE, THE SELECTION BEING MADE SO AS TO PROVIDE AT LEAST ONE ACID COMPONENT, AT LEAST ONE COMPOUND CONTAINING THE NITRATE RADICAL, AT LEAST ONE COMPOUND CONTAINING THE PHOSPHATE RADICAL, AND AT LEAST ONE AMMONIUM CONTAINING COMPONENT, SAID MIXTURE (C) HAVING A PH IN THE RANGE 2.0 TO 3.0, AND, IN A SECOND STAGE, TREATING THE PRODUCT MIXTURE FROM THE FIRST STAGE AT AN ELEVATED TEMPERATURE WITH A COUNTERCURRENT STREAM OF AMMONIA GAS WHEREBY ITS WATER CONTENT IS REDUCED AND AN AMMONIUM SALT CONTAINING LESS THAN 5% BY WEIGHT OF WATER IS OBTAINED, SAID BEING SELECTED FROM THE GROUP CONSISTING OF AMMONIUM NITRATE, AMMONIUM SULPHATE NITRATE, MONOAMMONIUM PHOSPHATE, DIAMMONIUM PHOSPHATE AND MIXTURES OF AMMONIUM PHOSPHATE AND AMMONIUM NITRATE.