Solvent extraction process for the recovery of uranium and rare earth metals from aqueous solutions

Claim 1

IN A PROCESS FOR RECOVERING HEAVY METAL VALUES FROM AN AQUEOUS SOLUTION BY SOLVENT EXTRACTION WITH AN ORGANIC SUBSTANTIALLY WATER-IMMISCIBLE SOLVENT, THE IMPROVEMENT WHICH CONSISTS IN CONTACTING THE AQUEOUS SOLUTION CONTAINING THE HEAVY METAL VALUES DISSOLVED THEREIN AS SOLUTE WITH DISCRETE GEL-LIKE WATER-INSOLUBLE ORGANIC SOLVENT-CONTAINING GRANULES OF A CROSS-LINKED INSOLUBLE ALKENYL AROMATIC RESIN CONSISTING ESSENTIALLY OF A COPOLYMER OF FROM 92 TO 99.5 PERCENT BY WEIGHT OF AT LEAST ONE MONOALKENYL AROMATIC HYDROCARBON HAVING THE GENERAL FORMULA: AR-C(-R)=CH2 WHEREIN AR REPRESENTS AN AROMATIC HYDROCARBON OF THE BENZENE SERIES AND R REPRESENTS A MEMBER OF THE GROUP CONSISTING OF HYDROGEN AND THE METHYL RADICAL, AND FROM 8 TO 0.5 PERCENT BY WEIGHT OF DIVINYL AROMATIC HYDROCARBON OF THE BENZENE SERIES, SAID COPOLYMER GRANULES CONTAINING ON THE SURFACE THEREOF SUBSTITUENT HYDROPHILE GROUPS OF THE FORMULA -SO3X WHEREIN X REPRESENTS A MEMBER OF THE GROUP CONSISTING OF HYDROGEN AND A METAL, IN AMOUNT CORRESPONDING TO FROM 0.001 TO 0.150 MILLIEQUIVALENT OF HYDROGEN ION PER GRAM OF SAID DRY SURFACESULFONATED RESIN, WHICH ALKENYL AROMATIC RESIN GRANULES ARE SWOLLEN WITH A WATER-IMMISICIBLE ORGANIC LIQUID COMPRISING A TRIALKYL PHOSPHATE HAVING FROM 4 TO 8 CARBON ATOMS IN EACH ALKYL RADICAL AS COMPLEXING AGENT FOR SAID HEAVY METAL VALUES IN SAID AQUEOUS SOLUTION, AND AN ORGANIC LIQUID SOLVENT WHICH SWELLS SAID ALKENYL AROMATIC RESIN, IN PROPORTIONS CORRESPONDING TO FROM 5 TO 80 PERCENT BY VOLUME OF THE ORGANIC SWELLING AGENT AND FROM 95 TO 20 PARTS BY VOLUME OF THE TRIALKYL PHOSPHATE, WHEREBY THE METAL VALUES ARE SORBED BY THE COMPLEXING AGENT IN SAID RESIN GRANULES, SEPARATING THE TREATED AQUEOUS SOLUTION FROM THE SOLVENT-CONTAINING RESIN GRANULES AND ELUTING THE HEAVY METAL VALUES FROM THE GEL-LIKE RESIN GRANULES BY WASHING SAID RESIN GRANULES WITH AN ELUANT SOLUTION COMPRISING WATER.