The Effect of Initial Solution pH on Surface Properties of Ferric Ion Precipitates Formed during Biooxidation of Ferrous Ion by Leptospirillum ferriphilum

Abstract:

While bioleaching is a proven technology for the efficient recovery of base metals from sulphide minerals, its sustenance is dependent on the continuous availability of ferric ion, Fe³⁺, in soluble form, in bioleach liquor. However, the solubility of ferric ion is low at higher pH thus resulting in the formation of various types of ferric ion precipitates, which decreases leaching efficiency by trapping the leached metals in solution through an adsorption. The effect of initial solution pH on the surface properties of ferric ion precipitates was investigated with a view to establish a relationship between operational pH and surface charge on precipitate and to relate this to the precipitates metal adsorption properties. Ferric ion precipitates recovered from a typical biooxidation process were characterized by XRD, SEM, PSD and zeta potential. Potassium-hydronium jarosite were the main phases identified by X-ray diffraction (XRD) analyses. The SEM results revealed that the precipitates had smooth surfaces with development of sharp edges on the precipitates formed at high pH. The precipitates formed at higher pH had less positive charge and scavenged more copper ions due to the high electrostatic attraction forces. The results from this study revealed that surface charge on a precipitate can give an indication of its metal adsorption capacity and that in order to prevent metal loss and improve extraction efficiency, solution conditions should be maintained such that the resulting precipitates have high positive surface charge to promote high electrostatic repulsion forces.

• Periodical: Solid State Phenomena (Volume 262)
• Pages: 403-407
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.262.403
• Online since: August 2017
• Authors: Bongo Mabusela, Tunde Victor Ojumu*
• Keywords: Bioleaching, Biooxidation, Jarosite, Metal Adsorption, Zeta Potential

References

[1] M. Wanjiya, F. Chowdhury, T. V. Ojumu, Solution Ph and Jarosite Management during Ferrous Ion Biooxidation in A Novel Packed-Column Bioreactor, Adv. Mat. Res. 1130 (2015) 291 - 295.

DOI: 10.4028/www.scientific.net/amr.1130.291

[2] S. I. Grishin, J. M. Bigham, O. H. Touvinen, Characterization of Jarosite Formed upon Bacterial Oxidation of Ferrous Sulfate in a Packed-Bed Reactor, Appl. Environ. Microbiol. 54 (1988) 3101 - 3106.

DOI: 10.1128/aem.54.12.3101-3106.1988

[3] S. Ju, Y. Zhang, P. Xue, Y. Wang, Clean hydrometallurgical route to recover zinc, silver, lead, copper, cadmium and iron from hazardous jarosite residues produced during zinc hydrometallurgy, J. Hazard Mater. 192 (2011) 554 - 558.

DOI: 10.1016/j.jhazmat.2011.05.049

[4] W. Nheta, M. E. Makhatha In Leaching of nickel from a jarosite precipitate with hydrochloric acid, 2013; International Conference on Chemical and Environmental Engineering (ICCEE'2013).

[5] K. A. Hudson-Edwards, K. Wright, Computer simulations of the interactions of the (012) and (001) surfaces of jarosite with Al, Cd, Cu2+ and Zn, Geochim. Cosmochim Ac. 75 (2011) 52 - 62.

DOI: 10.1016/j.gca.2010.10.004

[6] T. V. Ojumu, J. Petersen, The kinetics of ferrous ion oxidation by Leptospirillum ferriphilum in continuous culture: The effect of pH, Hydrometallurgy. 106 (2011) 5-11.

DOI: 10.1016/j.hydromet.2010.11.007

[7] G. -h. Gu, K. -t. HU, L. Shuang-ke, Surface characterization of chalcopyrite interacting with Leptospirillum ferriphilum, Trans. Nonferrous Met. Soc. China. 24 (2014) 1898 - (1904).

DOI: 10.1016/s1003-6326(14)63269-6

[8] J. P. Gramp, F. S. Jones, J. M. Bigham, O. H. Tuovinen, Monovalent cation concentrations determine the types of Fe (III) hydroxysulfate precipitates formed in bioleach solutions, Hydrometallurgy. 94 (2008) 29-33.

DOI: 10.1016/j.hydromet.2008.05.019

[9] J. Liu, B. Li, D. Zhong, L. Xia, G. Qiu, Preparation of jarosite by Acidithiobacillus ferrooxidans oxidation, J. Cent. South Univ. Technol. 14 (2007) 623-628.

DOI: 10.1007/s11771-007-0119-8

[10] J. M. Bigham, D. K. Nordstrom, Iron and aluminum hydroxysulfates from acid sulfate waters in: C.N. Alpers, J.L. Jambor, D.K. Nordstrom (Eds. ), Sulfate minerals, crystallography, geochemistry and environmental significance. Reviews in mineralogy and geochemistry, Mineralogical Society of America, Washington, D.C., 2000, p.351.

DOI: 10.1515/9781501508660-009

[11] A. H. Kaksonen, C. Morris, S. Rea, J. Li, K. M. Usher, R. G. McDonald, F. Hilario, T. Hosken, M. Jackson, C. A. du Plessis, Biohydrometallurgical iron oxidation and precipitation: Part II — Jarosite precipitate characterisation and acid recovery by conversion to hematite, Hydrometallurgy. 147–148 (2014).

DOI: 10.1016/j.hydromet.2014.04.015

[12] F. Chowdhury, T. V. Ojumu, Investigation of ferrous-iron biooxidation kinetics by Leptospirillum ferriphilum in a novel packed-column bioreactor: Effects of temperature and jarosite accumulation, Hydrometallurgy. 141 (2014) 36-42.

DOI: 10.1016/j.hydromet.2013.09.011

[13] J. Jonsson. Phase transformations and surface chemistry of secondary iron minerals formed from acid mine drainage. PhD Thesis, Umea University, (2003).