A novel process to efficiently produce anhydrous, oxide free MgCl 2 feed to a magnesium electrolysis cell is presented and examined in this thesis. The process involves reducing MgCl2 activity within a fused salt mixture via complexation and reacting any contaminating oxides that are mostly MgO with HCl(g). This process would not be possible nor economical if the MgCl2 activity was not reduced via complexation. This system is modeled here by treating the complexation as decreasing the MgCl2 activity coefficient in a fused salt mixture. / The chlorination was modeled thermodynamically using recently published thermodynamic data presented by Thompson et al. The model was experimentally verified. A kinetic model was also developed for the heterogeneous reaction between injected HCl gas and the MgO in fused salt. It was found that the rate of MgO elimination was proportional to C2/3MgO in the fused salt during the course of a kinetic batch test. The implication is that the rate of transport per unit area of MgO, of HCl to the MgO surface is constant for any particular condition which is only possible if the mass transport of HCl to the MgO particle surface is rate limiting. / The kinetics of MgO conversion were measured as a function of superficial gas velocity and mixing power per unit volume. The following relation empirically describes the conversion rate per unit area of MgO particle surface area wt%/min/m 2 for a given operating condition. km=0.001895Pg Vm0.8 3Vst 0.92 / Analysis of the kinetic information, confirmed the hypothesis for the mechanism of MgO elimination. / Measurements of the solubility of HCl(g) in fused salts were also taken. The findings show that the solubility of HCl varied between 270 ppmw to 2760 ppmw when the MgCl2 concentration was increased between 20 wt% to 70 wt% at 600°--650°C and a NaCl to CaCl2 weight ratio of 2.5--3.1. A mechanism for dissolution is presented.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.37701 |
| Date | January 1996 |
| Creators | Ficara, Pasquale. |
| Contributors | Harris, Ralph (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: 001810794, proquestno: NQ70184, Theses scanned by UMI/ProQuest. |
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