A comprehensive model of particle collection in flotation is developed from a rigorous analysis of the relative motion between a particle and a bubble prior to and during particle-bubble contact. Collection efficiency E(,K) is derived as a product of collision efficiency E(,C) and attachment efficiency E(,A). From trajectory calculations E(,C) is correlated to the bubble Reynolds number and the Stokes number, a dimensionless inertia term. E(,A) is calculated as the fraction of particles which reside on the bubble for a time greater than the induction time. As a result of the velocity gradient are the bubble surface E(,A) decreases with increasing particle size. The model explains the peak in size-by-size recovery data that is often observed at intermediate particle sizes. The peak location is shown to shift to smaller sizes as induction time increases. / A scale-up model for flotation columns is also developed. The model uses measured values of collection rate constants and an experimental correlation of plant column mixing parameters to calculate collection zone recovery R(,K). R(,K) is interfaced with a variable cleaning zone recovery to yield a grade-recovery relationship for the plant column. The onset of bubble loading is accounted for.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.71943 |
| Date | January 1984 |
| Creators | Dobby, G. S. (Glenn Stephen), 1952- |
| 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: 000216843, proquestno: AAINK66691, Theses scanned by UMI/ProQuest. |
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