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Quantification Of Pyrrhotiye O2 Consumption By Using Pyrite Oxidation Kinetic Data

  • I. Rojo (a1), F. Clarens (a1), J. de Pablo (a1), C Domènech (a2), L. Duro (a2), M. Grivé (a2) and D. Arcos (a2)...

Abstract

Experiments on the dissolution kinetics of natural pyrrhotite (FeS1-x-) and pyrite (FeS2) under imposed redox conditions to evaluate the oxygen uptake capacity of both minerals were carried out at 25°C and 1 bar. Experimental data indicate that in both cases, Fe(II) released from dissolution of these Fe-bearing sulphides is kinetically oxidized to Fe(III) to precipitate as Fe(III)-oxyhydroxides. While the system is pH controlled by the extent of the sulphide oxidation, Eh is controlled by the redox pair Fe2+/Fe(III)-oxyhydroxides. Pyrrhotite dissolution is faster than that of pyrite but generates less acidity. Consequently, the achieved redox value is more reducing. Experimental data show that the oxidation rates of both minerals (in mol·g-1·s-1) are equivalent under the studied conditions. This fact gives a new opportunity to quantify the reductive buffering capacity of pyrrhotite, for which no kinetic rate law has been still established.

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*Corresponding author: isabel.rojo@ctm.com.es

References

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1. Belzile, N., Chen, Y.W., Cai, M.F., Li, Y. (2004) A review on pyrrhotite oxidation. Journal of geochemical exploration 84, 6576.
2. Feng, D., van Deventer, J.S.J. (2002) Leaching behaviour of sulphidesin ammoniacalthiosulphate systems. Hydrometallurgy 63, 189200.10.1016/S0304-386X(01)00225-0
3. Gibbs, C. (1976). Characterization and application of ferrozine iron reagent as ferrous iron indicator. Anal. Chem. 48, 11971200.10.1021/ac50002a034
4. Janzen, M.P., Nicholson, R.V., Scharer, J.M. (2000) Pyrrhotite reaction kinetics: Reaction rates for oxidation by oxygen, ferric iron, and for nonoxidative dissolution. GeochimicaetCosmochimicaActa, 64(9) 15111522.
5. Murphy, R.;Strongin, , , D.R. (2009) Surface reactivity of pyrite and related sulfides. Surface Science Reports 64, 145.
6. Nicholson, R.V. (1994) Iron-sulfide oxidation mechanisms: laboratory studies. In Jambor, J.L., Blowes, D.W. (eds). Short course handbook on environmental geochemistry of sulfide mine wastes 22, Mineralogical Association of Canada, 163183.
7. Parkhurst, D.L.; Appelo, C.A.J. (1999) User’s guide to PHREEQC ((v. 2.17.5))-A computer program for speciation, batch-reaction, one-dimensional transport and inverse geochemical calculations. Washington D.C., USGS, Water resources investigations report 99-4259, 326p.
8. Scott, M.J., Morgan, J.J. (1990) Energetic and conservative properties of redox systems. In (eds) American Chemical Society, 368–378.
9. Singer, P.C. and Stumm, W. (1970) Acidic mine drainage: the rate determining step. Science 167, 11211123.
10. Wang, H. (2008) A review on process-related characteristics of pyrrhotite. Mineral Processing and Extractive Metallurgy Reviews, 29, 141.
11. Williamson, M.A., Rimstidt, J.D. (1994) The kinetics and electrochemical rate-determining step of aqueous pyrite oxidation. Geochimica et CosmochimicaActa 58(4), 54435454.

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