Industrial process for extracting rhenium

Claim 1

INDUSTRIAL PROCESS FOR THE EXTRACTION OF RHENIUM FROM MOLYBDENITE CONCENTRATE CONTAINING TRACES OF RHENIUM SULFIDE COMPRISING, AS A FIRST PHASE, THE HEATING OF THE CONCENTRATE IN AN OXIDIZING ATMOSPHERE TO A TEMPERATURE BY COM500* C., MAINTAINING THIS TEMPERATURE BY COMBUSTION OF THE COMBINED SULFUR UNTIL SUBSTANTIALLY ALL THE SULFUR HAS BEEN ELIMINATED AS SULFUR DIOXIDE, COLLECTING THE GASES EVOLVED DURING THE FIRST PHASE OF TREATMENT, SEPARATING THE MOLYBDENITE DUST CONTAINED THEREIN AND RETURNING SAME INTO THE PROCESS, THEN, AS A SECOND PHASE, SUPPLYING EXTERNATAL HEAT TO MAINTAIN THE MATERIAL AT A TEMPERATURE ABOVE APPROXIMATELY 550* C. BUT BELOW THE TEMPERATURE OF VOLATILIZATION OF MOLYBDENUM OXIDE, AND SUPPLYING OXYGEN WHEREBY THE RHENIUM COMPOUNDS ARE OXIDED TO RE207 AND THE LATTER VOLATILIZED, WHILE ENTRAINMENT OF THE MOLYBDENUM OXIDE IN THE EVOLVED GASES IS PRECLUDED BY A FUSING TOGETHER OF THE MOLYBDENUM OXIDE PARTICLES, COLLECTING SEPARATELY THE GASES EVOLVED DURING THIS SECOND PHASE OF THE PROCESS, AND SEPARATING THE RHENIUM OXIDE THEREFROM.