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Schwertmannite precipitated from acid mine drainage: phase transformation, sulphate release and surface properties

Jonsson, J.; Persson, Per LU ; Sjoberg, S. and Lovgren, L. (2005) In Applied Geochemistry 20. p.179-191
Abstract
Schwertmannite precipitated from acid mine drainage at the Kristineberg Zn-Cu mine in northern Sweden has been characterised regarding elemental composition, phase transformation as a function of pH and time. SO42- release and speciation of SO42- associated with the solid. The elemental analysis gave the composition FeSOS(OH)(5.02)(-SO4)(1.49) . 0.5H(2)O where approximately 1/3 of the SO42- is adsorbed to the surface. The conversion of schwertmannite to goethite at pH 9 was complete within 187 days; at pH 6. the conversion was still incomplete after 514 days. Lower pH and relatively high SO42- concentration decreased the conversion even further. Also temperature was shown to be an important parameter for this process and low temperature... (More)
Schwertmannite precipitated from acid mine drainage at the Kristineberg Zn-Cu mine in northern Sweden has been characterised regarding elemental composition, phase transformation as a function of pH and time. SO42- release and speciation of SO42- associated with the solid. The elemental analysis gave the composition FeSOS(OH)(5.02)(-SO4)(1.49) . 0.5H(2)O where approximately 1/3 of the SO42- is adsorbed to the surface. The conversion of schwertmannite to goethite at pH 9 was complete within 187 days; at pH 6. the conversion was still incomplete after 514 days. Lower pH and relatively high SO42- concentration decreased the conversion even further. Also temperature was shown to be an important parameter for this process and low temperature (+4 degreesC) effectively stopped the transformation at pH 3. The release of SO42- was linear with pH and X-ray photoelectron spectroscopy measurements confirming that the surface bound SO42- was released before bulk SO42-. Zeta potential measurements indicate a pH(IEP) of 7.2 for the schwertmannite sample. Prior to conversion into goethite, the SO42- associated with schwertmannite was indicated by attenuated total reflectance FTIR spectroscopy to be present both as bulk and surface species. Furthermore: the speciation of surface SO42- was shown to vary with pH and two predominating species were detected. As pH increases. SO42- is increasingly Coordinated in an outer sphere mode whereas a stronger. possibly inner sphere, complex dominates. at low pH. (C) 2004 Elsevier Ltd. All rights reserved. (Less)
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author
publishing date
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publication status
published
subject
in
Applied Geochemistry
volume
20
pages
179 - 191
publisher
Elsevier
external identifiers
  • scopus:9644276982
ISSN
0883-2927
DOI
10.1016/j.apgeochem.2004.04.008
language
English
LU publication?
no
id
44ea2e4e-58cd-4ffb-b185-f40bf6419eac (old id 4332513)
date added to LUP
2014-03-04 09:40:34
date last changed
2017-10-01 03:53:08
@article{44ea2e4e-58cd-4ffb-b185-f40bf6419eac,
  abstract     = {Schwertmannite precipitated from acid mine drainage at the Kristineberg Zn-Cu mine in northern Sweden has been characterised regarding elemental composition, phase transformation as a function of pH and time. SO42- release and speciation of SO42- associated with the solid. The elemental analysis gave the composition FeSOS(OH)(5.02)(-SO4)(1.49) . 0.5H(2)O where approximately 1/3 of the SO42- is adsorbed to the surface. The conversion of schwertmannite to goethite at pH 9 was complete within 187 days; at pH 6. the conversion was still incomplete after 514 days. Lower pH and relatively high SO42- concentration decreased the conversion even further. Also temperature was shown to be an important parameter for this process and low temperature (+4 degreesC) effectively stopped the transformation at pH 3. The release of SO42- was linear with pH and X-ray photoelectron spectroscopy measurements confirming that the surface bound SO42- was released before bulk SO42-. Zeta potential measurements indicate a pH(IEP) of 7.2 for the schwertmannite sample. Prior to conversion into goethite, the SO42- associated with schwertmannite was indicated by attenuated total reflectance FTIR spectroscopy to be present both as bulk and surface species. Furthermore: the speciation of surface SO42- was shown to vary with pH and two predominating species were detected. As pH increases. SO42- is increasingly Coordinated in an outer sphere mode whereas a stronger. possibly inner sphere, complex dominates. at low pH. (C) 2004 Elsevier Ltd. All rights reserved.},
  author       = {Jonsson, J. and Persson, Per and Sjoberg, S. and Lovgren, L.},
  issn         = {0883-2927},
  language     = {eng},
  pages        = {179--191},
  publisher    = {Elsevier},
  series       = {Applied Geochemistry},
  title        = {Schwertmannite precipitated from acid mine drainage: phase transformation, sulphate release and surface properties},
  url          = {http://dx.doi.org/10.1016/j.apgeochem.2004.04.008},
  volume       = {20},
  year         = {2005},
}