Location of Repository

MULTIPLE REACTION FRONTS IN THE OXIDATION-REDUCTION OF IRON-RICH URANIUM ORES*

By J. N. Dewynnef, A. C. Fowler and P. S. Hagan

Abstract

Abstract. This paper describes the oxidation of iron-rich uranium-bearing rocks by infiltration of groundwater. A reaction-diffusion model is set up to describe the sequence of reactions involving iron oxidation, uranium oxidation and reduction, sulphuric acid production, and dissolution of the host rock that occur. On a geological timescale of millions of years, the reactions occur very fast in very thin reaction fronts. It is shown that the redoxfront that separates oxidized (orange) rock from reduced (black) rock must actually consist of two separate fronts that move together, at which the two separate processes of uranium oxidation and iron reduction occur, respectively. Between these fronts, a high concentration of uranium is predicted. The mechanics of this process are not specific to uranium-mediated redox reactions, but apply generally and may be used to explain the formation of concentrated ore deposits in extended veins. On the long timescales of relevance, a quasi-static response results, and the problem can be solved explicitly in one dimension. This provides a framework for studying more realistic two-dimensional problems in fissured rocks and also for the future study of uraninite nodule formation. Key words, reaction-diffusion, oxidation-reduction, reaction fronts AMS(MOS) subject classifications. 35K57, 76S05, 86A6

Year: 2011
OAI identifier: oai:CiteSeerX.psu:10.1.1.190.7819
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://citeseerx.ist.psu.edu/v... (external link)
  • http://www.maths.ox.ac.uk/%7Ef... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.