Particle flow visualization in quartz slurry inside a hydrocyclone using the positron emission particle tracking technique Jennifer Rachel Radman a,⇑ , Raymond Langlois a , Thomas Leadbeater b , James Finch a , Neil Rowson c , Kristian Waters a a Department of Mining & Materials Engineering, McGill University, 3610 University Street, Montreal, Quebec H3A OC5, Canada b School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom c School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom article info Article history: Received 1 August 2013 Revised 16 March 2014 Accepted 18 March 2014 Available online xxxx Keywords: Classification Hydrocyclones Mineral processing PEPT Positron emission particle tracking abstract For the past 120 years, hydrocyclones have been used a wide variety of industrial applications, with their main use in mineral processing being as a classifier. Hydrocyclone characterization relies heavily on empirical and phenomenological models. There is a need to develop a method by which the flow patterns can be quantified under industrial conditions. Positron emission particle tracking (PEPT), developed by the University of Birmingham in the late 1980s, has proven to be a powerful in situ visualization tool for engineering applications. This paper presents data on the motion of quartz particles in a two-inch hydrocyclone using the PEPT technique. Quartz tracer particles were labeled using the direct activation technique. The particle size range was between À2000 and +150 lm which illustrates the flow pattern of particles reporting to the underflow. Crown Copyright Ó 2014 Published by Elsevier Ltd. All rights reserved. 1. Introduction Hydrocyclones are widely used in industrial processes with their main use in mineral processing being as a classifier. They are deceptively simple processing units as they have no moving parts, however, their performance is complex and difficult to pre- dict. The feed enters tangential to the hydrocyclone body under pressure which establishes the primary outer spiral which flows downwards towards the apex forming the underflow. A secondary spiral is set up simultaneously rotating upwards to the vortex fin- der forming the overflow. These two spiral flows make up the main flow pattern. The classical theory considers that orbiting particles within the flow pattern are subjected to two opposing forces – an outward centrifugal force and an inward drag force. Faster settling particles will move towards the outer wall of the hydrocy- clone where the primary spiral flow takes them to the apex while slower settling particles move towards the secondary spiral which takes them to the vortex finder. The centrifugal field of the hydro- cyclone flow is superimposed by an intensive and rapid mixing ef- fect, mainly caused by the macroturbulence of the flow (Schubert, 2010). The turbulence level within small hydrocyclones is strongly affected by the rotation of the flow (Dyakowski and Williams, 1993). The internal flow of the hydrocyclone is complex and remains a challenge to visualize under practical, i.e., opaque, conditions. Pos- itron emission particle tracking (PEPT), developed at University of Birmingham in the 1980s, has been successfully used to visualize flow in a number of unit operations. These include: mixing vessels (Barigou, 2004; Marigo et al., 2013); fluidised beds (Van de Velden et al., 2008); tumbling mills (Bbosa et al., 2011; Volkwyn et al., 2011); and more recently in flotation cells (Waters et al., 2008; Fan et al., 2009; Cole et al., 2010) and spiral concentrators (Waters et al., 2012). The strength of PEPT is that opaque systems can be investigated whereas previous tracking methods require direct visualization of particles (Dabir and Petty, 1986; Hsieh and Rajamani, 1988; Jirun et al., 1990; Monredon et al., 1992; Fisher and Flack, 2002 Lim et al., 2010; Marins et al., 2010). The research presented in this paper is the visualization of real-time flow of a particle inside a two-inch hydrocyclone by the PEPT technique. Recently, Chang et al. (2011) reported the underflow trajectory of a single resin bead particle labeled with ion-exchange technique inside a hydrocyclone using PEPT. The main drawback to their work from a mineral processing point of view is the lack of a slurry system. This paper tracks a quartz particle in a slurry system under a closed loop system. The tracer particle is of the same type of http://dx.doi.org/10.1016/j.mineng.2014.03.019 0892-6875/Crown Copyright Ó 2014 Published by Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +1 514 398 1454. E-mail address: jennifer.radman2@mail.mcgill.ca (J.R. Radman). Minerals Engineering xxx (2014) xxx–xxx Contents lists available at ScienceDirect Minerals Engineering journal homepage: www.elsevier.com/locate/mineng Please cite this article in press as: Radman, J.R., et al. Particle flow visualization in quartz slurry inside a hydrocyclone using the positron emission particle tracking technique. Miner. Eng. (2014), http://dx.doi.org/10.1016/j.mineng.2014.03.019