Influence of particle shape on flotation performance

Peter T L Koh, David I. Verrelli

    Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionpeer-review

    6 Citations (Scopus)

    Abstract

    Recent experimental measurements of induction time made by direct observation with the 'Milli-Timer' indicated that angular particles were able to attach much more rapidly than spherical particles. There was around a tenfold difference in the respective induction periods for particle-bubble attachment. For industrial application, a more holistic comparison is needed, with the induction period for attachment being just one input. Over the years, CSIRO has developed a CFD-flotation model that incorporates both rigorous hydrodynamics, to simulate real industrial cell geometries, and a detailed model of the embedded flotation process, in which the induction period is an important parameter. We conducted transient modelling of batch flotation. First, spherical particles were modelled, as a 'baseline', for different particle sizes and levels of hydrophobicity. In the second set of results, the induction period was decreased by a factor of up to ten, simulating flotation of angular particles. Flotation recovery was found to depend upon induction period in a complex manner. For highly hydrophobic or fine particles, the induction period for spheres was already so low that recovery was limited by other factors (e.g. bubble-particle collision frequency). Further decreases in induction period, as for angular particles, did not have a significant effect on recovery in these cases. By contrast, when weakly hydrophobic or coarse particles were modelled, the recovery was predicted to be greatly enhanced for angular particles, in comparison to spheres. For these particles the induction period was limiting recovery, so that the flotation rate constant could be improved directly by reducing the induction period. This is consistent with batch flotation experiments using Ballotini reported earlier. Therefore, when dealing with weakly hydrophobic particles or relatively large particles that are to be floated, an enhancement can be expected for more angular particle shapes. In such cases, judicious specification of the grinding circuit may improve the overall efficiency.

    Original languageEnglish
    Title of host publicationProceedings of the XXVII International Mineral Processing Congress – IMPC 2014
    EditorsJuan Yianatos, Alex Doll, Cesar Gomez, Romke Kuyvenhoven
    Place of PublicationChile
    PublisherGecamin
    Pages1-11
    Number of pages11
    Publication statusPublished - Oct 2014
    Event27th International Mineral Processing Congress, IMPC - 2014 - Santiago, Chile
    Duration: 20 Oct 201424 Oct 2014

    Other

    Other27th International Mineral Processing Congress, IMPC - 2014
    CountryChile
    CitySantiago
    Period20/10/1424/10/14

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