Solvent extraction process for the recovery of vanadium values

Claim 1

IN A PROCESS FOR THE RECOVERY OF VANADIUM VALUES INCLUDING THE STEPS OF INTIMATELY CONTACTING AN AQUEOUS SOLUTION CONTAINING VANADIUM VALUES TO BE RECOVERED AND CONTAMINATING IRON VALUES WITH A SUBSTANTIALLY WATER IMMISCIBLE ORGANIC SOLVENT EXTRACTANT TO PRODUCE A LOADED SOLVENT EXTRACTANT PHASE CONTAINING ABSORBED VANADIUM VALUES AND IRON, AT LEAST A PORTION OF THE ABSORBED IRON BEING IN THE FERRIC OXIDATION STATE, SEPARATING THE RESULTING LOADED SOLVENT EXTRACTANT PHASE FROM THE AQUEOUS SOLUTION, INTIMATELY CONTACTING THE SEPARATED LOADED SOLVENT EXTRACTANT PHASE WITH A 10 TO 20% SULFURIC ACID STRIPPING SOLUTION FOR THE ABSORBED VANADIUM VALUES AND AT LEAST A PORTION OF THE ABSORBED FERRIC IRON TO PRODUCE AN AQUEOUS STRIPPING SOLUTION CONTAINING DESORBED VANADIUM VALUES AND FERRIC IRON, THEREAFTER SEPARATING THE STRIPPING SOLUTION FROM THE EXTRACTANT PHASE AND RECOVERING THE VANADIUM VALUES THEREFROM, THE IMPROVEMENT COMPRISING INTIMATELY CONTACTING THE STRIPPING SOLUTION CONTAINING THE DESORBED FERRIC IRON WITH A REDUCING AGENT THEREFOR WHEREBY FERRIC IRON IS REDUCED TO THE FERROUS STATE, THEREAFTER INTIMATELY CONTACTING THE SOLVENT EXTRACTANT PHASE WITH THE STRIPPING SOLUTION TO STRIP ADDITIONAL ABSORBED IRON THEREFROM, SEPARATING THE STRIPPING SOLUTION FROM THE SOLVENT EXTRACTANT PHASE, AND THEN INTIMATELY CONTACTING ADDITIONAL AQUEOUS SOLUTION CONTAINING VANADIUM VALUES TO BE RECOVERED WITH THE SEPARATED SOLVENT EXTRACTANT PHASE.