Investigation of barium treatment of chromite ore processing residue

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dc.contributor.author Wazne, Mahmoud
dc.contributor.author Chrysochoou, Maria
dc.contributor.author Dermatas, Dimitris
dc.contributor.author Moon, Doek Hyun
dc.contributor.author Christodoulatos, Christos
dc.contributor.author French, Chris
dc.contributor.author Morris, John
dc.contributor.author Kaouris, Maria
dc.date.accessioned 2017-07-27T06:48:15Z
dc.date.available 2017-07-27T06:48:15Z
dc.date.copyright 2017 en_US
dc.date.issued 2017-08-10
dc.identifier.issn 1546-962X en_US
dc.identifier.uri http://hdl.handle.net/10725/5967
dc.description.abstract Barium addition to chromite ore processing residue COPR was investigated in order to address a the pronounced heaving phenomena that are associated with mainly the presence of ettringite and b hexavalent chromium leaching. Sulfate was added to representative samples of grey-black GB and hard-brown HB COPR to simulate worst-case conditions of sulfate influx and ettringite formation. Both the X-ray powder diffraction XRPD and the modeling results showed that ettringite is a thermodynamically favored reaction in COPR. The subsequent addition of barium lead to the formation of both barite and barium chromate, observed as solid solution between the two phases. Modeling results confirmed that barium sulfate is the more stable species that will dissolve ettringite and that barium chromate will also dissolve COPR chromate phases when sulfate is depleted. The Toxicity Characteristic Leaching Procedure TCLP test on GB samples showed that the optimal stoichiometry to maintain Cr and Ba TCLP concentrations below the U.S. Environmental Protection Agency regulatory limit of 5 and 100 ppm, respectively, lies between 1:1 Ba to sulfate plus chromate ratio and 1.5:1. The respective optimal stoichiometry for the HB COPR was found to be higher, between 2:1 and 5:1. Considering that COPR is actually a Crcontaminated cement form, a further area of research is the identification of barium-containing wastes i.e., heavy-metal sludges, contaminated soils, etc. that would be suitable for combination with COPR; in this way, an environmentally sustainable yet cost-effective treatment application can be realized. en_US
dc.language.iso en en_US
dc.title Investigation of barium treatment of chromite ore processing residue en_US
dc.type Article en_US
dc.description.version Published en_US
dc.author.school SOE en_US
dc.author.idnumber 201205627 en_US
dc.author.department Civil Engineering en_US
dc.description.embargo N/A en_US
dc.relation.journal Journal of ASTM International en_US
dc.journal.volume 3 en_US
dc.journal.issue 6 en_US
dc.article.pages 165-175 en_US
dc.keywords COPR en_US
dc.keywords Chromate en_US
dc.keywords Hexavalent chromium en_US
dc.keywords Ettringite en_US
dc.keywords Heaving en_US
dc.keywords Barium en_US
dc.identifier.ctation Chrysochoou, M., Dermatas, D., Moon, D. H., Christodoulatos, C., Wazne, M., French, C., ... & Kaouris, M. (2006). Investigation of barium treatment of chromite ore processing residue (COPR). In Contaminated Sediments: Evaluation and Remediation Techniques. ASTM International. en_US
dc.author.email mahmoud.wazne@lau.edu.lb en_US
dc.identifier.tou http://libraries.lau.edu.lb/research/laur/terms-of-use/articles.php en_US
dc.identifier.url https://compass.astm.org/download/STP37685S.32648.pdf en_US
dc.author.affiliation Lebanese American University en_US

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