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dc.contributor.advisorCohen, Ronald R. H.
dc.contributor.authorBray, Jared M.
dc.date.accessioned2007-01-03T05:36:17Z
dc.date.accessioned2022-02-09T08:40:54Z
dc.date.available2007-01-03T05:36:17Z
dc.date.available2022-02-09T08:40:54Z
dc.date.issued2013
dc.identifierT 7313
dc.identifier.urihttps://hdl.handle.net/11124/79435
dc.description2013 Summer.
dc.descriptionIncludes illustrations (some color).
dc.descriptionIncludes bibliographical references (pages 80-86).
dc.description.abstractThe mining and milling activities associated with extraction of metals directly generates waste in the form of mine tailings. This material is one of the largest sources of heavy metal contamination via water, air, flora, and fauna in the world. The re-use of this waste as an input to a construction material such as concrete could lead to a preventive method of reducing the environmental impact. This method of encapsulation of heavy metals has been applied to paste backfill; however, the compressive strength requirements are much lower compared to the ASTM standards for structural concrete. The objectives of this study were: (a) to examine the feasibility of maintaining the structural integrity of concrete, with compressive strength of 4,000 psi or greater with a slump of 3-4 inches, when using mine tailings as a fine aggregate, (b) investigate the ability of this material to encapsulate heavy metals, sulfates, and acid. The waste material, collected from the Pride of the West mill in Silverton, CO, was first physically and chemically characterized. After performing batch leach extraction tests, the raw mine tailing leachate contained heavy metal concentrations above conservative regulatory limits. Then, the optimal tailing to fine aggregate ratio was investigated. It was found that the compressive strength was comparable to control samples made with aggregate and the concentration of heavy metals found in the leachate were consistently low when the ratio varied below 50%. Therefore, the ASTM standard for the minimum allowable fineness modulus was used to obtain in maximum amount of mine tailings allotted in the concrete mixture. To examine whether metals could be leached from the concrete-tails mix, three extraction fluids varying in pH were used to accelerate the weathering process. The metals of concern were shown to have been thoroughly encapsulated in the concrete matrix, with a 2-4 log encapsulation capacity when compared to the metals leached from the raw tailings. Finally, a strength development experiment was conducted to observed changes over time. It was found that the specimens that contained mine tailings maintained comparable compressive strengths as the controls cylinders, above the minimum compressive strength requirements for structural concrete.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado School of Mines. Arthur Lakes Library
dc.relation.ispartof2010-2019 - Mines Theses & Dissertations
dc.rightsCopyright of the original work is retained by the author.
dc.subjectleachability
dc.subjectencapsulation
dc.subjectconcrete
dc.subjectmine tailings
dc.subjectsolidification
dc.subjectstabilization
dc.subject.lcshTailings (Metallurgy)
dc.subject.lcshLeachate
dc.subject.lcshReinforced concrete
dc.subject.lcshHeavy metals
dc.subject.lcshAggregates (Building materials)
dc.subject.lcshHazardous substances -- Environmental aspects
dc.titlePotential leachability of mine tailings encapsulated in structural concrete, The
dc.typeText
dc.contributor.committeememberKiousis, Panagiotis Demetrios, 1956-
dc.contributor.committeememberWayllace, Alexandra
thesis.degree.nameMaster of Science (M.S.)
thesis.degree.levelMasters
thesis.degree.disciplineCivil and Environmental Engineering
thesis.degree.grantorColorado School of Mines


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