University of Birmingham and IMERYS.
Tax free bursary of £15,500 p.a. plus fees paid
3 year project duration

Positron emission particle tracking (PEPT) was developed at the University of Birmingham (UK) as a means to follow the motion of individual particles in engineering equipment. For PEPT analysis, a tracer particle is labelled with a radionuclide (generally fluorine-18: 18F). This allows the path of the particle to be monitored in real time in a non-invasive particle tracking system.

In a number of processing systems, and especially large volume mineral processing systems, being able to track the motion of particles would be extremely beneficial to design engineers. This understanding would be able to enhance and validate mathematical models that predict the motion, and therefore the performance and energy efficiency of such systems. It would also allow mill design to be optimised and validated.

Previously the investigation of the vertically stirred mill using positron tracking of a grinding media particle has proved to be highly effective in the analysis of flow patterns within the mill. By highlighting the interior dynamics of the flow fields, new information regarding the flow patterns can be seen. Analysis of the full data sets allows measurement of the height of the flow field, as well as the area of the field and the distribution of time spent by the media in different parts of the mill.

It is important to note that large scale grinders are not identical in shape to their lab scale equivalents. Many industrial grinders have baffles in place to disrupt the flow, and it is also common for the mill chamber to be octagonal, rather than cylindrical in shape. The work reported in this proposal could be extended to account for such variables, as has been considered previously.  

Work will been extended to compare the measurements made with PEPT to real physical properties of the grind, such as particle size reduction, and rate of surface area generation. Also the data generated on media flow has been used to calculate impact forces in the grinding operation and relate these to particle size distributions for calcium carbonate milling. The PEPT technique has been proved to be a valuable analytical tool for the optimisation of laboratory scale grinding, with further ramifications for scale up and full scale industrial mineral processing.

Due to funding restrictions this project is only open to UK/EU students.  Candidates must have at least a 2(1) BEng/MEng degree in Chemical or Mineral Engineering.

Please email your c.v. to n.a.rowson@bham.ac.uk by clicking the APPLY button below

Closing date for applications is 05/11/2013