Hydrometallurgical Extraction of Molybdenum and Rhenium from Molybdenite Flue Dust

Abstract

Herein, the leaching of molybdenum and rhenium from the molybdenite roasting flue dust in H2SO4 was studied. The parametric studies showed that leaching performed at a pulp density, 10 wt./vol.%; H2SO4 concentration, 1.0 M; temperature, 90 °C; and time, 90 min was sufficient to yield 96% molybdenum and 93% rhenium. The leaching process significantly improved by raising the temperature from 30 °C to 90 °C, indicating an exothermic dissolution of refractory metals. Whereas the leaching kinetics indicated that the reaction mechanism changed from diffusion-controlled to chemically controlled, which was further confirmed by the apparent activation energy evaluated to be Ea(Mo), 35.5 kJ/mol, and Ea(Re), 21.5 kJ/mol.