Process of separating niobium and tantalum values in oxidic ores and of producing pure niobium

Claim 1

IN A METHOD OF SEPARATING NIOBIUM VALUES FROM TANTALUM VALUES IN A MATERIAL CONTAINING THE OXIDES OF NIOBIUM, TANTALUM AND IRON BY A THERMITE TYPE REACTION IN WHICH THE SAID OXIDE CONTAINING MATERIAL IS MIXED WITH A REDUCING METAL TO FORM A REACTION MIXTURE AND THE REDUCING REACTION IS STARTED BY THE APPLICATION OF HEAT, THE IMPROVEMENT CONSISTING OF FURNISHING IN THE SAID REACTION MIXTURE COPPER VALUES, SELECTED FROM THE CLASS CONSISTING OF COPPER AND COPPER OXIDES, IN AN AMOUNT SUFFICIENT TO PRODUCE DURING THE REACTION A MASS OF MOLTEN COPPER IN WHICH WILL PHYSICALLY COLLECT THE NIOBIUM AND IRON PRODUCED BY SAID REDUCTION AND LIMITING THE REDUCING METAL CONTENT OF THE REACTION MIXTURE TO AN AMOUNT NOT SUBSTANTIALLY EXCEEDING THAT THEORETICALLY REQUIRED TO REDUCE THE NIOBIUM IRON AND COPPER OXIDE CONTENT OF THE MIXTURE FROM OXIDE TO METAL, WHEREBY THE RESULTANT NIOBIUM AS SO COLLECTED IS SUBSTANTIALLY FREE OF SAID REDUCING METAL EXCEPT AS AN IMPURITY.