Effect of Coatings on Mineral Reaction Rates in Acid Mine Drainage

Simple item page
dc.contributor.authorHuminicki, Danielle Marie Ceceliaen
dc.contributor.committeechairRimstidt, J. Donalden
dc.contributor.committeememberSchreiber, Madeline E.en
dc.contributor.committeememberChermak, John A.en
dc.contributor.committeememberDove, Patricia M.en
dc.contributor.departmentGeosciencesen
dc.date.accessioned2014-03-14T20:14:44Zen
dc.date.adate2006-09-29en
dc.date.available2014-03-14T20:14:44Zen
dc.date.issued2006-07-24en
dc.date.rdate2008-09-29en
dc.date.sdate2006-08-04en
dc.description.abstractThis dissertation includes theoretical and applied components that address the effect of coatings on rates of mineral reactions that occur in acid mine drainage (AMD) environments. The two major projects investigated how diffusion-limited transport of reactants through pore spaces in coatings on mineral grains affects the reaction rate of the underlying mineral. The first project considered the growth of gypsum coatings on the surface of dissolving limestone in anoxic limestone drains (ALD), which reduces the neutralization rate of the dissolving limestone and the subsequent effectiveness of this treatment. The second project investigated the conditions where iron oxyhydroxide coatings form on oxidizing pyrite and the potential strategies to prevent "runaway" AMD by reducing the rate of acid production to the point that the acid can be neutralized by the surrounding rocks. In both studies, experiments were conducted to measure reaction rates for the underlying minerals, as coatings grew thicker. These experimental data were fit to a diffusion model to estimate diffusion coefficients of reactants through pore spaces in coatings. These models are extrapolated to longer times to predict the behavior of the coated grains under field conditions. The experimental results indicate that management practices can be improved for ALDs and mine waste piles. For example, supersaturation with respect to gypsum, leading to coating formation, can be avoided by diluting the ALD feed solution or by replacing limestone with dolomite. AMD can be prevented if the rate of alkalinity addition to mine waste piles is faster than acid is produced by pyrite oxidation. The diffusion model developed in this study predicts when iron oxyhydroxide coatings will become thick enough that alkalinity from the surroundings is sufficient to neutralize acid produced by coated pyrite oxidation and additional alkalinity is no longer required.en
dc.description.degreePh. D.en
dc.identifier.otheretd-08042006-150936en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08042006-150936/en
dc.identifier.urihttp://hdl.handle.net/10919/28519en
dc.publisherVirginia Techen
dc.relation.haspartHuminickiDISSERTATION.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectalkalinityen
dc.subjectpyrite oxidation ratesen
dc.subjectiron oxyhydroxide coatingsen
dc.subjectcalcite dissolution ratesen
dc.subjectacid mine drainageen
dc.subjecthydrodynamicsen
dc.subjectlimonite pseudomorphsen
dc.subjectgypsum coatingsen
dc.subjectanoxic limestone drainen
dc.titleEffect of Coatings on Mineral Reaction Rates in Acid Mine Drainageen
dc.typeDissertationen
thesis.degree.disciplineGeosciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
HuminickiDISSERTATION.pdf
Size:
1.04 MB
Format:
Adobe Portable Document Format
Download

Collections

Doctoral Dissertations