Production of complete fertilizers

Claim 1

A PROCESS FOR PREPARING FERTILLIZERS WHICH COMPRISES THE FOLLOWING STEPS; STEP 1, TREATING PHOSPHATE ROCK WITH A MIXED ACID CONTAINING NITRIC ACID AND AT LEAST ONE ACID FROM THE GROUP CONSISTING OF SULFURIC AND PHOSPHORIC ACIDS IN THE PROPORTIONS OF FROM ABOUT 7 TO ABOUT 20 EQUIVALENTS OF MIXED ACID PER MOL OF P2O5 IN THE PHOSPHATE ROCK, SAID MIXED ACID CONTAINING NITRIC ACID IN AMOUNT OF FROM ABOUT 40% TO ABOUT 80% OF THE ACID EQUIVALENTS, THE ACIDULATION OF THE ROCK BEING CARRIED OUT IN THE PRESENCE OF WATER AMOUNTING TO FROM ABOUT 15% TO ABOUT 40% BY WEIGHT OF THE TOTAL MIXTURE; STEP 2, AMMONIATING THE ACIDULATED MATERIAL EMPLOYING FROM ABOUT 0.6 TO ABOUT 0.8 MOL OF AMMONIA PER EQUIVALENT OF ACID AND SUFFICIENT WATER SO THAT THE AMMORIATED MATERIAL LEAVING THE AMMONIATION TREATMENT CONTAINS FROM ABOUT 15% TO ABOUT 30% BY WEIGHT OF WATER AND INCORPORATING A POTASSIUM SALT IN AMOUNT TO PRODUCE A FINAL PRODUCT CONTAINING FROM ABOUT 7% TO ABOUT 20% BY WEIGHT OF K2O; STEP 3, MIXING THE MATERIAL FROM STEP 2 WITH A PORTION OF THE DRY PRODUCT FROM STEP 4 TO PRODUCE A MIXTURE CONTAINING FROM ABOUT 15% TO ABOUT 45% BY WEIGHT OF LIQUID AT A TEMPERATURE OF FROM ABOUT 60* TO ABOUT 80* C.; AND STEP 4, DRYING THE RESULTANT MIXTURE TO PRODUCE A FERTILIZER CONTAINING NOT MORE THAN ABOUT 2% BY WEIGHT OF MOISTURE AND WITHDRAWING AS PRODUCT DRIED MIXTURE NOT PASSED TO STEP 3.