Process for recovery of pure v2o5 from vanadium bearing materials

Claim 1

IN A PROCESS OF RECOVERING VANADIUM COMPOUNDS IN EXCESS OF 99.5% PURITY FROM VANADIUM-BEARING MATERIAL, INCLUDING ROASTING SUCH A VANADIUM-BEARING MATERIAL MIXED WITH SODIUM CHLORIDE AND IN FINELY DIVIDED CONDITION AT A TEMPERATURE OF ABOUT 800*C. UNDER OXIDIZING CONDITIONS SO AS TO FORM WATER SOLUBLE SODIUM VANADATE SUBSTANTIALLY FREE OF SILICON, IRON, CHROMIUM AND PHOSPHORUS, LEACHING THE ROAST CALCINE WITH WATER AND ESTABLLISHING A PH OF ABOUT 5.5 TO 6 IN THE LEACH SOLUTION, AND FILTERING THE LEACHING SLURRY FOR SEPARATION OF THE SODIUM VANADATE SOLUTION FROM INSOLUBLES, THE IMPROVEMENT WHICH COMPRISES EXTRACTING THE ANIONIC VANADIUM OXIDE COMPONENT OF THE SODIUM VANADATE COMPOUND IN THE AQUEOUS LEACH SOLUTION INTO A LIQUID-TO-LIQUID ION EXCHANGE ORGANIC SOLUTION WHICH CONSISTS OF A WATER INSOLUBLE AMINE COMPLEXING AGENT HAVING THREE LONG CHAIN ALIPHATIC HYDROCARBON GROUPS, EACH HAVING 8 TO 10 CARBON ATOMS, AND SULFATE IONS IN THE MOLECULE, SAID COMPOUND BEING DISSOLVED IN AN ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF KEROSENE AND FUEL OIL TO OBTAIN A TWO-PHASE LIQUID MIXTURE, SEPARATING THE ORGANIC PHASE FROM THE AQUEOUS PHASE CONTAINING METALLIC CATIONIC IMPURITIES, EXTRACTING THE VANADIUM ION FROM THE SEPARATED ORGANIC PHASE BY MIXING WITH AN AQUEOUS SOLUTION CONTAINING AMMONIUM CHLORIDE AND AMMONIA IN QUANTITIES NOT LESS THAN 9% AMMONIUM CHLORIDE BY WEIGHT AND NOT LESS THAN 1% AMMONIA BY WEIGHT TO MAINTAIN A PH OF AT LEAST 8 AND THEREBY FORM A THREE-PHASE MIXTURE OF AN ORGANIC PHASE, AN AQUEOUS PHASE, CONTAINING AMMONIA CHLORIDE AND AMMONIA, AND A SOLID JPHASE OF CRYSTALLINE AMMONIUM METAVANADATE IN THE FORM OF A SLURRY IN THE AQUEOUS PHASE, SEPARATING THE ORGANIC JPHASE FROM THE AQUEOUS JPHASE CONTAINING THE CRYSTALLINE AMMONIUM VANADATE, SEPARTING THE AMMONIA VANDATE FROM THE AQUEOUS PHASE BY FILTRATION, AND SUBJECTING THE CRYSTALLINE AMMONIUM METAVANADATE TO HEATING TO FORM PURE VANADIUM PENTOXIDE CONTAINING NOT LESS THAN 99.5% V2O5.