Bux, J, Peakall, J, Biggs, S et al. (1 more author) (2015) In situ characterisation of a concentrated colloidal titanium dioxide settling suspension and associated bed development: Application of an acoustic backscatter system. Powder Technology, 284. 530 - 540. ISSN 0032-5910
Abstract
The ability to accurately characterise the settling of particulate suspensions is imperative in numerous industries for improved processing, optimisation and control. Characterisation is typically a non-trivial process, and in situ measurements that remove the restriction of requiring particular sample sizes are preferred. Here, for the first time, we explore the use of an acoustic backscatter system (ABS) to characterise key settling dynamics within a common colloidal mineral suspension, where backscatter attenuation is heightened due to the associated low scattering cross sections of the particles. Settling titanium dioxide dispersions with concentrations ranging from 0.05 to 3.00. vol% were successfully profiled using ABS transducers of 1, 2 and 4. MHz frequencies. This approach enabled the simultaneous visualisation of both the settling interface and sediment bed formation, generating sedimentation curves and elucidating settling velocities. Furthermore, backscatter attenuation was empirically correlated with the attenuation-concentration relationship established for homogenous dispersions, to obtain concentration profiles of the settling suspensions. The data depicted concentration changes as a function of time in a hindered settling suspension, and allowed observation of the segregation of a size polydisperse suspension. Data were compared with sedimentation data obtained via two common ex situ bench scale techniques. Critically, the acoustic backscatter method was validated as a powerful in situ characterisation tool for opaque concentrated heterogeneous dispersions, with the ability to provide concentration density information in conjunction with settling kinetics that are not easily attainable via other methods.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 Elsevier B.V. This is an author-produced version of a paper published in Powder Technology. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Acoustic backscatter; Colloidal; Sedimentation; Characterisation; Concentration |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) > Institute for Particle Science and Engineering (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 09 Sep 2015 11:57 |
Last Modified: | 29 Oct 2016 06:47 |
Published Version: | http://dx.doi.org/10.1016/j.powtec.2015.07.028 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.powtec.2015.07.028 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:89601 |