The kinetics of calcium and sodium removal at 730$ sp circ$C by chlorination from commercial purity (99.7% Al) and aluminum-1wt% magnesium alloys has been investigated. The contribution of chlorine containing gas bubbles, of intermediate reaction products generated by the chlorination process, as well as evaporation through the melt surface, to the removal of calcium and/or sodium has been documented quantitatively. Experimental parameters investigated were chlorine concentration in the gas bubbles and gas flow rate. The measurement of frequency of bubble formation at the tip of the gas bubbling nozzle enabled the surface areas of the bubbles to be estimated which in turn enabled melt phase mass transfer coefficients for the bubbles to be calculated. / It was demonstrated that the removal of calcium and sodium followed first order reaction kinetics with respect to calcium and sodium concentrations. The removal of the above mentioned elements was represented well by a kinetic model in which mass transfer of sodium and calcium in melt phase was rate limiting. / In the case of the magnesium containing alloys, the MgCl$ sb2$ salt phase that was generated during chlorination was found to have a profound effect on the removal of calcium and sodium. The contribution of the salt phase to the removal of these elements was calculated to reach as high as 60%. In commercial purity aluminum, however, while the major contribution to the removal of calcium was from the chlorine containing gas bubbles, the major contribution to the removal of sodium was calculated to be evaporation of sodium through the melt surface.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.39752 |
| Date | January 1992 |
| Creators | Külünk, Bahadir |
| Contributors | Guthrie, R. I. L. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Mining and Metallurgical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001326875, proquestno: NN87542, Theses scanned by UMI/ProQuest. |
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