An investigation into column flotation of South African coals

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dc.contributor.authorVon Holt, Sean Thomasen_ZA
dc.date.accessioned2016-09-28T19:06:24Z
dc.date.available2016-09-28T19:06:24Z
dc.date.issued1992en_ZA
dc.descriptionBibliography: pages 245-254.en_ZA
dc.description.abstractThe high efficiency of separation of fine (typically the -150 μm fraction) particles achievable with column flotation technology is well established. The principal aim of this thesis is to investigate whether column flotation can be used to recover saleable, particularly low-ash quality, coal from South African coal fines which are presently discarded. Samples of thickener underflow fines from the Durnacol, Kleinkopje and Greenside Collieries were used in laboratory column testwork. In addition, on-line column trials were performed at the Kleinkopje Colliery. The effects of co 1 umn operating parameters were established using both one-variable-at-a-time testing and fractional factorial design experiments. An investigation into coal slurry conditioning using oil and oil-water dispersions was also undertaken. The results of laboratory and plant column testwork showed that it was possible to recover the desired quality products from all three of the coal fines samples investigated. For all the coals tested, better grades were obtained at any given yield from column cell flotation than with conventional (batch) froth flotation. The test results also demonstrated that the column cell is best suited to recovering and upgrading the finer (< 75 μm) size fractions. Column performance was found to be strongly affected by the petrographic composition of the coal fines feed, i.e. by coal TYPE. Coals with high vitrinite and, conversely, low inertinite contents were found to be the most easily floatable. Depending on the coal TYPE, the rate of mass transport in either the pulp or froth phase was found to be rate limiting; this in turn dictated which operating parameters affected product yields and grades. Existing methods of conditioning coal slurries were found to be inadequate. Considerable scope for improvement in coal conditioning lies in better choice of collector and "promotor" reagents as well as in designing more energetically efficient conditioning vessels.en_ZA
dc.identifier.apacitationVon Holt, S. T. (1992). <i>An investigation into column flotation of South African coals</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering. Retrieved from http://hdl.handle.net/11427/21992en_ZA
dc.identifier.chicagocitationVon Holt, Sean Thomas. <i>"An investigation into column flotation of South African coals."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering, 1992. http://hdl.handle.net/11427/21992en_ZA
dc.identifier.citationVon Holt, S. 1992. An investigation into column flotation of South African coals. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Von Holt, Sean Thomas AB - The high efficiency of separation of fine (typically the -150 μm fraction) particles achievable with column flotation technology is well established. The principal aim of this thesis is to investigate whether column flotation can be used to recover saleable, particularly low-ash quality, coal from South African coal fines which are presently discarded. Samples of thickener underflow fines from the Durnacol, Kleinkopje and Greenside Collieries were used in laboratory column testwork. In addition, on-line column trials were performed at the Kleinkopje Colliery. The effects of co 1 umn operating parameters were established using both one-variable-at-a-time testing and fractional factorial design experiments. An investigation into coal slurry conditioning using oil and oil-water dispersions was also undertaken. The results of laboratory and plant column testwork showed that it was possible to recover the desired quality products from all three of the coal fines samples investigated. For all the coals tested, better grades were obtained at any given yield from column cell flotation than with conventional (batch) froth flotation. The test results also demonstrated that the column cell is best suited to recovering and upgrading the finer (< 75 μm) size fractions. Column performance was found to be strongly affected by the petrographic composition of the coal fines feed, i.e. by coal TYPE. Coals with high vitrinite and, conversely, low inertinite contents were found to be the most easily floatable. Depending on the coal TYPE, the rate of mass transport in either the pulp or froth phase was found to be rate limiting; this in turn dictated which operating parameters affected product yields and grades. Existing methods of conditioning coal slurries were found to be inadequate. Considerable scope for improvement in coal conditioning lies in better choice of collector and "promotor" reagents as well as in designing more energetically efficient conditioning vessels. DA - 1992 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1992 T1 - An investigation into column flotation of South African coals TI - An investigation into column flotation of South African coals UR - http://hdl.handle.net/11427/21992 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/21992
dc.identifier.vancouvercitationVon Holt ST. An investigation into column flotation of South African coals. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Department of Chemical Engineering, 1992 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/21992en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Chemical Engineeringen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherChemical Engineeringen_ZA
dc.titleAn investigation into column flotation of South African coalsen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMSc (Eng)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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