Production of refractory metals

Claim 1

A METHOD OF PRODUCING PURIFIED REFRACTORY METAL, WHICH METHOD COMPRISES THE STEPS OF DISPOSING AN OXIDE OF A REFRACTORY METAL IN A CLOSED REACTION ZONE WITH A REDUCING AGENT ESSENTIALLY COMPRISING AT LEAST ONE RARE EARTH METAL WHOSE OXIDE HAS A SUFFICIENTLY HIGH HEAT OF FORMATION TO SUSTAIN AN OXIDATION-REDUCTION REACTION WITH SAID METAL OXIDE AND HAVING SUFFICIENTLY LOW MUTUAL SOLUBILITY WITH SAID METAL SO AS TO BE PRESENT ONLY IN TRACE AMOUNTS IN THE PURIFIED METAL, SAID REDUCING AGENT BEING PRESENT IN A CONCENTRATION TO REACT WITH ESSENTIALLY ALL OF SAID METAL OXIDE, HEATING SAID METAL OXIDE AND SAID REDUCING AGENT INSAID ZONE TO ABOVE THE TEMPERATURE REQUIRED FOR INTIATING A SELF SUSTAINING OXIDATION-REDUCTION REACTION THEREBETWEEN, THE TEMPERATURE OF THE REACTION BEING ABOVE THE MELTING POINT OF SAID METAL, THEREAFTER COOLING SAID ZONE TO AMBIENT TEMPERATURE, AND SEPARATING SAID METAL IN SOLID MASSIVE FORM.

Claim 2

A METHOD OF PRODUCING PURIFIED REFRACTORY METAL, WHICH METHOD COMPRISES THE STEPS OF DISPOSING AN OXIDE OF A REFRACTORY METAL IN A CLOSED REACTION ZONE WITH A REDUCING AGENT ESSENTIALLY COMPRISING AT LEAST ONE RARE EARTH METAL WHOSE OXIDE HAS A SUFFICIENTLY HIGH HEAT OF FORMATION TO SUSTAIN AN OXIDATION-REDUCTION REACTION WITH SAID METAL OXIDE AND HAVING SUFFICIENTLY LOW MUTUAL SOLUBILITY WITH SAID METAL SO AS TO BE PRESENT ONLY IN TRACE AMOUNTS IN THE PURIFIED METAL, SAID REDUCING AGENT BEING PRESENT IN A CONCENTRATION TO REACT WITH ESSENTIALLY ALL OF SAID METAL OXIDE, HEATING SAID METAL OXIDE AND SAID REDUCING AGENT INSAID ZONE TO ABOVE THE TEMPERATURE REQUIRED FOR INTIATING A SELF SUSTAINING OXIDATION-REDUCTION REACTION THEREBETWEEN, THE TEMPERATURE OF THE REACTION BEING ABOVE THE MELTING POINT OF SAID METAL, THEREAFTER COOLING SAID ZONE TO AMBIENT TEMPERATURE, AND SEPARATING SAID METAL IN SOLID MASSIVE FORM.