Process for producing phosphatecontaining fertilizers

Claim 1

THE PROCESS OF PRODUCING A COMPLEX FERTILIZER CONTAINING NITROGEN IN THE FORM OF NITRATES AND NITROGEN IN AMMONIATED FORM AND PHOSPHORIC ACID IN THE FORM OF PHOSPHATES SOLUBLE IN AMMONIUM CITRATE WHICH COMPRISES TREATING PHOSPHATE ROCK WITH NITRIC ACID IN AN AMOUNT SUFFICIENT TO RENDER WATER SOLUBLE PRACTICALLY ALL THE PHOSPHATE INITIALLY CONTAINED IN SAID PHOSPHATE ROCK, INTRODUCING INTO THE DISINTEGRATION MIXTURE AMMONIA IN AN AMOUNT SUFFICIENT TO RENDER THE MASS TO A PH NOT SUBSTANTIALLY LESS THAN PH 7 AND DURING THE AMMONIATION WHEN THE PH OF THE MASS IS BETWEEN 2.5 AND 6.7, ADDING TO THE REACTION-MIXTURE FROM 1 TO 5 G-ATOMS OF STABILIZING METAL IONS SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM-, ALUMINUM-, IRON(II)-, AND IRON (III)-IONS AND MIXTURES THEREOF PER EACH 100 MOLES OF P2O5 PRESENT, ADDING TO THE REACTION-MIXTURE PRIOR TO THE COMPLETION OF THE AMMONIATION SUFFICIENT AMMONIUM SALTS SELECTED FROM THE GROUP CONSISTING OF AMMONIUM PHOSPHATE, AMMONIUM SULPHATE AND MIXTURES THEREOF TO ADJUST THE MOLERATIO OF CAO TO P2O5 WITHIN THE RANGE OF FROM 1.5 TO 2.1, EXCLUSIVE OF SUCH CALCIUM WHICH IS PRESENT AS CALCIUM SULPHATE AND CALCIUM FLUORIDE IN THE INITIAL ROCK.