Molybdenum recovery process

Claim 1

A PROCESS FOR PRODUCING HIGH PURITY MOLYBDENUM WHICH COMPRISES: (A) LEACHING MOLYBDENUM TRIOXIDE BEARING MATERIAL WITH AN AQEUOUS AMMONIACAL AMMONIUM SULPHATE SOLUTION TO OBTAIN SUBSTANTIALLY COMPLETE EXTRACTION OF MOLYBDENUM THEREFROM AND ITS DISSOLUTION IN THE LEACH SOLUTION, (B) MAINTAINING THE FREE AMMONIA CONCENTRATION OF SAID LEACH SOLUTION AT AT LEAST ABOUT 1 OF AMMONIA PER MOLE OF MOLYBDENUM IN SOLUTION AND MAINTAINING THE AMMONIUM SULPHATE CONCENTRATION OF SAID LEACH SOLUTION AT ABOVE 100 GRAMS PER LITRE; (C) SEPARATING UNDISSOLVED RESIDUE FROM THE LEACH SOLUTION AND REACTING SAID SOLUTION, IN THE PRESENCE OF A CATALYST, AT A TEMPERATURE OF FROM ABOUT 200*F. TO ABOUT 450*F. WITH HYDROGEN GAS PROVIDED IN SUFFICIENT AMOUNT TO MAINTAIN A HYDROGEN PARTIAL PRESSURE ABOVE ABOUT 200 POUNDS PER SQUARE INCH, SAID CATALYST BEING AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF SALTS OF THE PRECIOUS METALS SILVER, GOLD, PALLADIUM AND PLATINUM WHICH ARE SOLUBLE IN THE AMMONICAL LEACH SOLUTION AND FINELY DIVIDED METAL POWDERS; (D) CONTINUING SAID REDUCING REACTION TO PRECIPITATE MOLYBDENUM FROM SAID SOLUTION AS A COMPLEX MOLYBDENUM SALT; AND (E) SEPARATING THE PRECIPITATED COMPLEX MOLYBDENUM SALT FROM THE LAST-MENTIONED SOLUTION AND HEATING SAID PRECIPITATE, IN THE PRESENCE OF A REDUCING AGENT, AT A TEMPERATURE BELOW THAT AT WHICH MOLYBDENUM TRIOXIDE VOLATILIZES TO REDUCE THE MOLYBDENUM PRECIPITATE TO SUBSTANTIALLY PURE MOLYBDENUM METAL.