Digestion of phosphate rock

Claim 1

THE METHOD OF RECOVERING A SUBSTANTIALLY NON-HYGROSCOPIC CALCIUM PHOSPHATE PRODUCT FROM PHOSPHATE ROCK CONTAINING CALCIUM PHOSPHATE WHICH COMPRISES DISSOLVING THE PHOSPHOROUS COMPONENT OF THE ROCK IN AN INORGANIC NITROGENOUS ACID WITH THE RESULTING FORMATION OF AN ACIDIC AQUEOUS PHASE CONTAINING SUBSTANTIALLY ALL OF THE ACID-SOLUBILIZED CALCIUM AND PHOSPHORUS COMPONENTS OF THE ROCK IN THE FORM OF CALCIUM NITRATE AND PHOSPHORIC ACID; ADDING TO SAID CALCIUM-AND PHOSPHORIC-CONTAINING AQUEOUS PHASE AN ALKALI METAL SALT OF THE GROUP CONSISTING OF POTASSIUM CHLORIDE, SODIUM CHLORIDE AND SODIUM SULFATE IN AN AMOUNT SUCH THAT, IN ADDITION TO THE AMOUNT THEREOF CONSUMED BY THE RESULTING PRECIPITATION OF A SUBSTANTIAL PORTION OF ANY ACIDSOLUBLE FLUORINE COMPONENT OF THE ROCK IN THE FORM OF AN INSOLUBLE ALKALI METAL FLUOSILICATE, THERE WILL BE FURTHER INCORPORATED IN SAID AQUEOUS PHASE AN AMOUNT OF THE ALKALI METAL SALT AT LEAST SUBSTANTIALLY EQUIVALENT STOICHIOMETRICALLY TO THE CALCIUM NITRATE CONTENT OF SAID AQUEOUS PHASE; AND AFTER ADDITION OF SAID AMOUNT OF THE ALKALI METAL SALT ADDING AMMONIA TO THE ALKALI METAL SALT-CONTAINING AQUEOUS PHASE, THUS PRECIPITATING THERFROM THE AFORESAID DISSOLVED CALCIUM AND PHOSPHUOROUS COMPONENTS OF THE ROCK IN THE FORM OF A SUBSTANTIAL NON-HYGROSCOPIC CALCIUM PHOSPHATE PRODUCT.

Claim 2

THE METHOD OF RECOVERING A SUBSTANTIALLY NON-HYGROSCOPIC CALCIUM PHOSPHATE PRODUCT FROM PHOSPHATE ROCK CONTAINING CALCIUM PHOSPHATE WHICH COMPRISES DISSOLVING THE PHOSPHOROUS COMPONENT OF THE ROCK IN AN INORGANIC NITROGENOUS ACID WITH THE RESULTING FORMATION OF AN ACIDIC AQUEOUS PHASE CONTAINING SUBSTANTIALLY ALL OF THE ACID-SOLUBILIZED CALCIUM AND PHOSPHORUS COMPONENTS OF THE ROCK IN THE FORM OF CALCIUM NITRATE AND PHOSPHORIC ACID; ADDING TO SAID CALCIUM-AND PHOSPHORIC-CONTAINING AQUEOUS PHASE AN ALKALI METAL SALT OF THE GROUP CONSISTING OF POTASSIUM CHLORIDE, SODIUM CHLORIDE AND SODIUM SULFATE IN AN AMOUNT SUCH THAT, IN ADDITION TO THE AMOUNT THEREOF CONSUMED BY THE RESULTING PRECIPITATION OF A SUBSTANTIAL PORTION OF ANY ACIDSOLUBLE FLUORINE COMPONENT OF THE ROCK IN THE FORM OF AN INSOLUBLE ALKALI METAL FLUOSILICATE, THERE WILL BE FURTHER INCORPORATED IN SAID AQUEOUS PHASE AN AMOUNT OF THE ALKALI METAL SALT AT LEAST SUBSTANTIALLY EQUIVALENT STOICHIOMETRICALLY TO THE CALCIUM NITRATE CONTENT OF SAID AQUEOUS PHASE; AND AFTER ADDITION OF SAID AMOUNT OF THE ALKALI METAL SALT ADDING AMMONIA TO THE ALKALI METAL SALT-CONTAINING AQUEOUS PHASE, THUS PRECIPITATING THERFROM THE AFORESAID DISSOLVED CALCIUM AND PHOSPHUOROUS COMPONENTS OF THE ROCK IN THE FORM OF A SUBSTANTIAL NON-HYGROSCOPIC CALCIUM PHOSPHATE PRODUCT.