Effect of Residual Bitumen on Polymer-assisted Flocculation of Fluid Fine Tailings

  • Author / Creator
    Klein, Colin G
  • In bitumen recovery from oil sands, a percentage of the bitumen is lost to tailings.
    The effect of fugitive bitumen on fines settling and consolidation in tailings ponds
    remains controversial. In the current study, the settling performance of mature
    fine tailings (MFT) in response to flocculant addition was considered by studying
    MFT of varying bitumen content. Bitumen content in the MFT was adjusted by
    controlled removal of bitumen using a Denver flotation cell. The initial settling
    rate of flocculated MFT was observed to increase with decreasing bitumen
    content from 0.45 to 0.18 wt%. A further reduction in bitumen content was found
    to dramatically decrease the settling rate of flocculated MFT. Such behaviour
    seems counterintuitive since the polymer flocculant was found to have a low
    affinity for bitumen contaminated surfaces, as measured by quartz crystal
    microbalance with dissipation (QCM‐D), which would predict a further increase
    in settling rate of flocculated MFT with decreasing bitumen content. Reasons for
    this behavior were investigated and it was observed that the decrease in settling
    rate coincided with long periods of intense mixing in the Denver cell. The
    underlying reason for this behavior is the subject of ongoing investigation. The
    current study confirms the use of flotation as a viable option to control MFT
    bitumen content and improve the settling rate of flocculated MFT.

  • Subjects / Keywords
  • Graduation date
    Spring 2014
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.