Process of treating vanadium and molybdenum ores

Claim 1

A PROCESS FOR TREATING AN ORE MATERIAL CONTAINING OXIDES OF VANADIUM AND MOLYDBENUM WHICH COMPRISES SMELTING THE ORE MATERIAL WITH A CAUSTIC FLUX, SEPARATING SLAG CONTAINING WATER SOLUBLE COMPOUNDS OF VANADIUM AND MOLYDBENUM, LEACHING SAID SLAG WITH WATER AND SEPARATING AN ALKALINE LEACH SOLUTION RICH IN VANADIUM AND MOLYDBENUM, REACTING SAID LEACH SOLUTION WITH LIME TO PRECIPITATE CALCIUM VANADATE THEREFROM WHILE WHILE LEAVING THE MOLYBDENUM SUBSTANTIALLY ENTIRELY IN THE RESIDUAL LEACH SOLTION, EXTRACTING THE PRECIPITATED CALCIUM VANDATE WITH SULFURIC ACID TO OBTAIN AN ACIDIC VANADIUM-RICH LIQUOR FROM WHICH VANADIUM CAN BE RECOVERED AND LEAVING A CALCIUM SULFATE RESIDUE, CONCENTRATING A MAJOR PORTION OF SAID RESIDUAL ALKALINE LEACH SOLUTION AND RECYCLING THE RESULTANT CONCENTRATE AS FLUX IN THE SMELTING STEP, WITHDRAWING AT LEAST A PORTION OF SAID RESIDUAL LEACH SOLUTION WITHOUT RECYCLING THE SAME, AND REACTING THE WITHDRAWN PORTION OF RESIDUAL LEACH SOLUTION WITH SAID CALCIUM SULFATE RESIDUE AND PRECIPITATING CALCIUM MOLYBDATE WHEREBY TO PERMIT RECOVERY OF MOLYBDENUM AND AT THE SAME TIME PREVENTING EXCESSIVE ACCUMULATION OF MOLYBDENUM IN THE SYSTEM AS A RESULT OF RECYCLING SAID CONCENTRATE.