Leaching Systems of Wolframite and Scheelite: A Thermodynamic Approach

• Type: Another Publication in an International Scientific Journal
• Date: 2014

Authors

José Inácio Martins (Author) FEUP

Journal

Title: Mineral Processing and Extractive Metallurgy Review

Vol. 35

Pages: 23-43

ISSN: 0882-7508

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 16 Citations

ISI Web of Science

Scopus - 25 Citations

Other information

Authenticus ID: P-006-HSK

DOI: 10.1080/08827508.2012.757095

Abstract (EN): A linear correlation between free energy and enthalpy for crystalline and soluble oxocompounds based in the Sverjensky-Molling equation is used to calculate the Gibbs free energies of formation of MnWO4 (-1172.48 +/- 12.76kJmol(-1)), H2WO4 (-1006.91 +/- 10.36kJmol(-1)), and Na2WO4 (-1455.39 +/- 12.81kJmol(-1)). Using these data with the known thermodynamic data, the equilibrium constants for reactions of leaching of scheelite and wolframite in acidic and basic media were determined. The results show that the acid route based in relatively cheap inorganic acids is desirable for scheelite digestion, despite the diffusion problems concerned with tungstic acid developed on the solid particles. Meanwhile, wolframite may be operated under favorable thermodynamics conditions by alkaline and acid processes.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 21