Selective Leaching-Recovery of Re and Mo from Out-Gas Dust of Molybdenite Roasting Furnace

Selective leaching and recovery of Mo and Re present in out-gas dust of molybdenite roasting furnace was quantitatively investigated. The effects of solid to liquid (S/L) phase ratio, sulfuric acid concentration and solution temperature on the selective extraction were determined. Considerable Mo and small amount of Re were detected in the out-gas dust of the industrial roasting furnaces. Recovery percentage of both Re and Mo increased by increasing acid concentration and solution temperature. The results also showed that the recovery percentage of Re decreased by increasing the S/L ratio. The best conditions for selective leaching was obtained as 20 min mixing in water (0 g/L sulfuric acid) with S/L ratio of 0.2 in the temperature range of 40–60 °C.