Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-19T23:59:34.793Z Has data issue: false hasContentIssue false

Anaerobic pyrite oxidation rates determined via direct volume-loss measurements: a Vertical Scanning Interferometric approach

Published online by Cambridge University Press:  05 July 2018

E. R. Avery*
Affiliation:
Earth and Biosphere Institute, School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK
L. G. Benning
Affiliation:
Earth and Biosphere Institute, School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK

Abstract

Presented here are quantitative dissolution rate data (volume of pyrite lost/time) for the inorganic oxidation of pyrite in synthetic, anaerobic and acidic (pH 2) hydrothermal vent fluids (HVF) from experiments where the volume loss was measured directly via Vertical Scanning Interferometry (VSI). The VSI-derived reaction rate was 2.12x10-10±1.14x10-1 mol/m2/min, which is ∼2 to 4 orders of magnitude slower than pyrite oxidation rates previously determined using traditional batch experiments where rates are calculated based on changes in solution chemistry. This lower rate stems primarily from differences in experimental conditions (i.e. water to rock ratios, vigorous vs. gentle stir rates, grain-size effects, time), yet the rates derived here are believed to be more representative of pyrite oxidation in natural environments where more static and high solution to solid rate conditions prevail, such as seafloor conditions or acid-mine-drainage environments.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arvidson, R.S., Beig, M.S. and Lüttge, A. (2004) Single-crystal plagioclase feldspar dissolution rates measured by vertical scanning interferometry. American Mineralogist, 89, 51–56.CrossRefGoogle Scholar
Asta, M.P., Cama, J., Soler, J.M., Arvidson, R.S. and Luttge, A. (2008) Interferometric study of pyrite surface reactivity in acidic conditions. American Mineralogist, 93, 508–519.CrossRefGoogle Scholar
Beig, M.S. and Lüttge, A. (2006) Albite dissolution kinetics as a function of distance from equilibrium: Implications for natural feldspar weathering. Geochimica et Cosmochimica Ada, 70, 1402–1420.CrossRefGoogle Scholar
Edwards, K.J., McCollom, T.M., Konishi, H. and Buseck, P.R. (2003) Seafloor bio-alteration of sulfide minerals: Results from in-situ. incubation studies. Geochimica et Cosmochimica Ada, 67, 2843–2856.CrossRefGoogle Scholar
Golden Software, Inc. (1997) Surfer (Win 32. Ver. 6.04. Surface Mapping System.Google Scholar
Lüttge, A., Bolton, E.W. and Lasaga, A.C. (1999) An interferometric study of the dissolution kinetics of anorthite: the role of reactive surface area. American Journal of Science, 299, 652–678.Google Scholar
McKibben, M.A. and Barnes, H.L. (1986) Oxidation of pyrite in low-temperature acidic solutions: rate laws and surface textures. Geochemica et Cosmochimica Ada. 50, 1509–1520.Google Scholar
Schippers, A. (2004) Biogeoehemistry of metal sulfide oxidation in mining environments, sediments, and soils. Pp. 83–96 in: Sulfür Biogeoehemistry — Past & Presen. (Amend, J.A., Edwards, KJ., Lyons, T., editors). GSA publications, Geological Society of America, Boulder, Colorado.Google Scholar
Smith, E.E. and Shumate, K.S. (1970) Sulfide to Sulfate Reaction Mechanisms. Water pollution control series. 14010 FPS 02/70. USEPA, Washington, D.C. Google Scholar
Williamson, M.A. and Rimstidt, J.D. (1994) The kinetics and electrochemical rate-determining step of aqueous pyrite oxidation. Geochemica et Cosmochimica Ada, 58, 5443–5454.Google Scholar