Using positron emission tomography (PET) to determine liquid content in overflowing foam

• Published in: Chemical engineering research & design Vol. 94; pp. 721 - 725
• Main Authors: Cole, K., Brito-Parada, P.R., Morrison, A., Govender, I., Buffler, A., Hadler, K., Cilliers, J.J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-02-2015
• Subjects: Chemical engineering; Flotation; Foam; Foams; Froth; Liquid fraction; Liquids; Materials recovery; Overflowing; PET; Positron emission; Tomography; Froth; Foam; Liquid fraction; PET
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2014.10.014

•Liquid content measurements in foams and froths are limited by their opaque nature.•Positron emission tomography was used to measure the dispersion of a liquid tracer.•The density of PET lines of response was used to find the liquid content of 2D foam.•The liquid content at the interface was 0.36 decreasing to 0.03 at the surface.•This technique can be applied to liquid content in 3D foams and flotation froths.
In froth flotation, liquid recovery is strongly linked to separation performance. In addition to determining its structure, the distribution of liquid within froth affects the recovery of entrained material to the concentrate. Despite its importance, measurements of the liquid content of froths are rare. Most existing measurements are intrusive, only provide low spatial resolution, or rely on small samples of foam. This work demonstrates the use of positron emission tomography (PET) to measure the distribution of liquid in a 2D overflowing foam. Results show a liquid fraction of 0.36 at the base of the foam column decreasing to a liquid fraction of 0.03 at the foam surface. This shows the potential to use PET studies to measure 3D foam structures and to validate simulations of flotation froths.