Uranium recovery from metallic masses

Claim 1

A PROCESS OF RECOVERING URANIUM FROM NEUTRON-IRRADIATED THORIUM-BASE METAL CONTAINING U233, PROTACTINIUM, ZIRCONIUM AND REAR-EARTH FISSION PRODUCTS, COMPRISING REACTING THE NEUTRON-IRRADIATED METAL WITH MAGNESIUM AT FROM 800 TO 900*C. WHEREBY THE MAGNESIUM, THE THORIUM AND PART OF THE FISSION PRODUCTS FROM A LIQUID ALLOY WHILE THE URANIUM AND THE PROTACTINIUM TOGETHER WITH A SMALL QUANTITY OF THE THORIUM AND SOME OF THE FISSION PRODUCTS REMAIN AS A SOLID METAL RESIDUE; SEPARATING THE SOLID METAL RESIDUE FROM THE LIQUID ALLOY; ADDING TO THE METAL RESIDUE A MOLTEN MIXTURE OF ZINC CHLORIDE AND THE EUTECTIC BETWEEN POTASSIUM CHLORIDE AND AN ALKALI CHLORIDE SELECTED FROM THE GROUP CONSISTING OF LITHIUM CHLORIDE AND SODIUM CHLORIDE; REACTING THE METAL RESIDUE WITH THE MOLTEN CHLORIDE MIXTURE AT A TEMPERATURE OF BETWEEN 450 AND 700*C. UNTIL EQUILIBRATION AS TO CHLORINATION AND ZINC FORMATION HAS BEEN REACHED; SEPARATING A METAL PHASE, CONTAINING NONCHLORINATED METALS AND ZINC FORMED, FROM A SALT PHASE CONTAINING THORIUM CHLORIDE, URANIUM CHLORIDE, PROTACTINIUM CHLORIDE, ZICONIUM CHLORIDE AND RARE-EARTH FISSION-PRODUCT CHLORIDES; ADDING A BINARY MAGNESIUM-CONTAINING (1-7%) ZINC-BASE ALLOY STEPWISE TO SAID SALT PHASE, IN THE FIRST STEP ADDING AN AMOUNT HAVING THE STOICHIOMETRIC QUANTITY OF ZINC FOR THE CONVERSION OF ALL THORIUM AND ALL ZIRCONIUM TO SALT-INSOLUBLE TH2ZN17 AND ZRZN14, RESPECTIVELY, IN THE SECOND STEP ADDING AN AMOUNT OF ALLOY CONTAINING FROM STOICHIOMETRIC QUANTITY TO AN 0.5% EXCESS OF ZINC FOR THE CONVERSION OF ALL URANIUM TO SALTINSOLUBLE U2ZN17 AND IN THE THIRD AND LAST STEP ADDING A LARGE EXCESS OF SAID ALLOY FOR THE PRECIPITATION OF PROTACTINIUM AS A ZINC COMPOUND, EACH TIME REMOVING THE INSOLUBLE METAL-ZINC COMPOUNDS PRIOR TO ADDING A NEW INSTALLMENT OF MAGNESIUM-CONTAINING ZINC-BASE ALLOY; AND HEATING THE URANIUM-CONTAINING INTERMETALLIC COMPOUND TO A TEMPERATURE ABOVE ABOUT 1100*C. WHEREBY THE ZINC AND ANY MAGNESIUM PRESENT VOLATILIZE AND PURE URANIUM METAL IS OBTAINED.