Production of potassium fxuotantajlate

Claim 1

IN THE EXTRACTION OF THE TANTALUM AND COLUMBIUM CONTENTS OF A TANTALUM ORE IN WHICH THE ORE IS DIGESTED IN A CONCENTRATED HYDROFLUORIC ACID-CONTAINING SOLUTION, THE RESULTING COLUMBIUM- AND TANTALUM-CONTAINING LIQUOR IS SEPARATED FROM THE ORE RESIDUE, THE TOTAL COLUMBIUM AND TANTALUM CONTENT OF THE LIQUOR (CALCULATED AS OXIDES) IS ADJUSTED BY THE ADDITION OF WATER IF NECESSARY TO NOT MORE THAN ABOUT 1.2 POUNDS PER GALLON AND ITS FLUORIDE CONTENT IS ADJUSTED TO ABOUT 5 TO 20% BY WEIGHT, THE ADJUSTED LIQUOR IS PASSED IN CONTACT WITH AN ANION-EXCHANGE RESIN CAPABLE OF REMOVING FROM THE LIQUOR ITS COLUMBIUM AND TANTALUM COMPONENTS, THE THUS-ABSORBED COLUMBIUM IS SELECTIVELY STRIPPED FROM THE RESIN BY ELUTING IT WITH AN AQUEOUS SOULTION OF AMMONIUM CHLORIDE ACIDIFIED WITH HYDROFLUORIC ACID, AND THEREAFTER THE ABSORBED TANTALUM IS STRIPPED FROM THE RESIN BY ELUTING IT WITH AN AQUEOUS SOLUTION OF AMMONIUM FLORIDE AND AMMONIUM CHLORIDE, THE IMPORVEMENT WHICH COMPRISES RECOVING THE ADSORBED TANTALUM COMPONENT IN A STATE CAPABLE OF BEING DIRECTLY CONVERTED TO POTASSIUM FLUOTANTALATE BY (A) INCORPORATING HYDROCHLORIC ACID IN THE DIGESTION LIQUOR IN AMOUNT SUCH THAT WHEN THE COLUMBIUM, TANTALUM AND FLUORIDE CONTENTS OF THE LIQUOR ARE ADJUSTED AS AFORESAID ITS CHLORIDE CONTENT IS ABOUT 1.5 TO 24% BY WEIGHT, (B) EFFECTING THE ELUTION OF THE ABSORBED TANTALUM FROM THE RESIN WITH A QUANTITY OF SAID ACIDIFIED AMMONIUM CHLORIDE ELUANT NOT IN EXCESS OF THAT WHICH WILL YIELD A SOLUTION COMPOSED ESSENTIALLY OF THE ELUANT CONTAINING AT LEAST 15 GRAMS PER LITER OF DISSOLVED TANTALUM (CALCULATED AS OXIDE), (C) ADDING TO THE RESULTING TANTALUM-CONTAINING SOLUTION A STOICHIOMETIC EXCESS OF POTASSIUM CHLORIDE AND AN AMOUNT OF ACID SUFFICIENT TO PROVIDE A STRONGLY ACIDIC SOLUTION OF POTASSIUM FLUOTANTALATE, AND (D) CRYSTALLIZING THE POTASSIUM FLUOTANTALATE FROM SAID SOLUTION THEREOF.