Cole Katie, Barker Daniel J, Brito-Parada Pablo R, Buffler Andy, Hadler Kathryn, Mackay Isobel, Mesa Diego, Morrison Angus J, Neethling Stephen, Norori-McCormac Alexander, Shean Barry, Cilliers Jan
Department of Physics, University of Cape Town, South Africa.
Department of Earth Science and Engineering, Imperial College London, UK.
MethodsX. 2022 Mar 26;9:101680. doi: 10.1016/j.mex.2022.101680. eCollection 2022.
Positron emission particle tracking (PEPT) is a technique for measuring the motion of tracer particles in systems of flow such as mineral froth flotation. An advantage of PEPT is that tracer particles with different physical properties can be tracked in the same experimental system, which allows detailed studies of the relative behaviour of different particle classes in flotation. This work describes the standard operating protocol developed for PEPT experiments in a flotation vessel at PEPT Cape Town in South Africa. A continuously overflowing vessel with constant air recovery enables several hours of data acquisition at steady state flow and consistent flotation conditions. Tracer particles are fabricated with different coatings to mimic mineral surface hydrophobicity and size, and a data treatment derived from a rotating disk study is utilized to produce high frequency (1 kHz) location data relative to the tracer activity. Time averaging methods are used to represent the Eulerian flow field and occupancy of the tracer behaviour based on voxel schemes in different co-ordinate systems. The average velocity of the flow in each voxel is calculated as the peak of the probability density function to represent the peak of asymmetrical or multimodal distributions.•A continuously overflowing flotation vessel was developed for extended data acquisition at steady state flow.•The data treatment enabled the direct comparison of different particle classes in the flotation vessel.•The solids flow fields was described by the probability density function of tracer particle velocity measured in different voxel schemes.
正电子发射粒子跟踪（PEPT）是一种用于测量示踪粒子在诸如矿物泡沫浮选等流动系统中运动的技术。PEPT的一个优点是可以在同一实验系统中跟踪具有不同物理性质的示踪粒子，这使得能够详细研究浮选过程中不同颗粒类别的相对行为。本文描述了在南非开普敦的PEPT实验室为浮选槽中的PEPT实验开发的标准操作流程。一个具有恒定空气回收率的连续溢流槽能够在稳定流和一致的浮选条件下进行数小时的数据采集。示踪粒子通过不同的涂层进行制备，以模拟矿物表面的疏水性和尺寸，并且利用从旋转盘研究中得出的数据处理方法来生成相对于示踪剂活性的高频（1 kHz）位置数据。基于不同坐标系中的体素方案，使用时间平均方法来表示欧拉流场和示踪剂行为的占有率。每个体素中的平均流速计算为概率密度函数的峰值，以表示不对称或多峰分布的峰值。
•开发了一个连续溢流的浮选槽，用于在稳定流条件下进行长时间的数据采集。
•该数据处理方法能够直接比较浮选槽中不同颗粒类别。
•通过在不同体素方案中测量的示踪粒子速度的概率密度函数来描述固体流场。
