Production of phosphoric acid from a phosphatic ore

Claim 1

PROCESS OF RECOVERING PHOSPHORIC ACID FROM A PHOSPHATE-CONTAINING ORE WHICH COMPRISES (A) MIXING SAID ORE WITH A PHOSPHORIC ACID EXTRACTING SOLUTION IN AMOUNTS SUFFICIENT TO DISSOLVE THE CALCIUM VALUES IN SAID ORE AND TO CONVERT SAID PHOSPHATE VALUES TO ACID-SOLUBLE CALCIUM PHOSPHATES. (B) SEPARATING THE RESULTING PHOSPHORIC ACID-CALCIUM PHOSPHATE EXTRACT FROM SOLID RESIDUES, (C) REACTING SAID PHOSPHORIC ACID-CALCIUM PHOSPHATE EXTRACT WITH HYDROFLUORIC ACID AND CONVERTING SAID CALCIUM PHOSPHATE TO CALCIUM FLUORIDE AND PHOSPHORIC ACID, (D) SEPARATING AN ENRICHED PHOSPHORIC ACID SOLUTION FROM SAID CALCIUM FLUORIDE, (E) REACTING SAID CALCIUM FLUORIDE WITH STEAM AND SILICON DIOXIDE IN A THERMAL REACTION ZONE AT TEMPERATURES OF FROM ABOUT 1000*C., TO 1400*C. TO PRODUCE HYDROGEN FLUORIDE AND A CALCIUM SILICATE RESIDUE, (F) RECOVERING SAID HYDROGEN FLURODE IN WATER TO FORM HYDROFLUORIC ACID, (G) RECYCLING SAID HYDROFLUORIC ACID TO SAID REACTION STAGE (C), (H) EXTRACTING THE PHOSPHATE VALUES OF THE SOLID RESIDUES FROM STEP (B) WITH A PORTION OF THE PHOSPHORIC ACID PRODUCED IN STEP (D), (I) RECYCLING SAID PHOSPHORIC ACID EXTRACT SOLUTION TO REACTION STAGE (A) TO DISSOLVE ADDITIONAL PHOSPHATE CONTAINING ORE, AND (J) WITHDRAWING THE REMAINDER OF THE PHOSPHORIC ACID FROM STEP (D) AS PRODUCT.