The Surface Chemistry Characterization of Pyrite, Sphalerite and Molybdenite after Bioleaching

Abstract:

The mineral surface chemistry characterization is essential to describe the dissolution kinetics in leaching and bioleaching. Five different methods, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy, have been applied to study the surface chemistry changes during pyrite, sphalerite and molybdenite bioleaching. The surface characterizations have been done for samples before and after biological and chemical leaching. The SEM images illustrated that the minerals surfaces were smooth before processing, while they covered with an ash layer after biological treatment. Although EDS analysis and Raman spectrum demonstrated the potassium jarosite formation on the pyrite surface during bioleaching, the formation of jarosite layer did not occur on the sphalerite surfaces during bioleaching. On the other hand, a sulfur layer formation on the sphalerite surface was confirmed by mentioned characterization methods. Finally, according to the XRD and EDS spectrum the molybdenite surface had been covered both with sulfur and jarosite.

• Periodical: Solid State Phenomena (Volume 262)
• Pages: 487-491
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.262.487
• Online since: August 2017
• Authors: Sina Ghassa*, Hadi Abdollahi, Mahdi Gharabaghi, Saeed Chehreh Chelgani, Mohammad Jafari
• Keywords: Bioleaching, Molybdenum, Pyrite, Sphalerite, Surface Chemistry

References

[1] A.D. Souza, P.S., Pina, V.A., Leao, Bioleaching and chemical leaching as an integrated process in the zinc industry, Min. Eng. 20‏ (2007) 591-599.

DOI: 10.1016/j.mineng.2006.12.014

[2] J. Han, W. Liu, W. Qin, B. Peng, K. Yang, Y. Zheng, Recovery of zinc and iron from high iron-bearing zinc calcine by selective reduction roasting, J. Ind. Eng. Chem. 22(2015)272-279.

DOI: 10.1016/j.jiec.2014.07.020

[3] R. Dehghan, M. Noaparast, M. Kolahdoozan, Leaching and kinetic modelling of low-grade calcareous sphalerite in acidic ferric chloride solution, Hydrometallurgy 96 (2009) 275-282.

DOI: 10.1016/j.hydromet.2008.11.002

[4] A.H. Kaksonen, C. Morris, S. Rea, J. Li, K.M. Usher, R. McDonald, F. Hilario, T. Hosken, M. Jackson, C. du Plessis, Biohydrometallurgical iron oxidation and precipitation: Part II –Jarosite precipitate characterisation and acid recovery by conversion to hematite, Hydrometallurgy. 147 (2014).

DOI: 10.1016/j.hydromet.2014.04.015

[5] S. Panda, A. Biswal, S. Mishra, P.K. Panda, N. Pradhan, U. Mohapatra, L.B. Sukla, B.K. Mishra, A. Akcil, Reductive dissolution by waste newspaper for enhanced meso-acidophilic bioleaching of copper from low grade chalcopyrite: A new concept of biohydrometallurgy, Hydrometallurgy. 153 (2015).

DOI: 10.1016/j.hydromet.2015.02.006

[6] K. Sasaki, Y. Nakamuta, T. Hirajima, O.H. Tuovinen, Raman characterization of secondary minerals formed during chalcopyrite leaching with Acidithiobacillus ferrooxidans, Hydrometallurgy. 95 (2009) 153-158.

DOI: 10.1016/j.hydromet.2008.05.009

[7] C. Varotsis, C. Giangou, S. Papadatos, Probing the formation of secondary minerals in the bioleaching reactions of chalcopyrite by Raman and FTIR microspectroscopy, New Biotechnology, 31 (2014) 139-151.

DOI: 10.1016/j.nbt.2014.05.1958