The schematic diagram of the Mineral-PET method.
MineralPET is a Research & Development project aimed at applying Nuclear Medicine techniques, like Positron Emission Tomography, to the identification and sorting of diamond-bearing kimberlite rocks. The project, based on a technique invented by the late Prof. JFP Sellschop and Simon Connell, is now lead by Simon Connell and Sergio Ballestrero, at the University of Johannesburg, in collaboration with UJ Technology transfer Office and Multotec.
As of March 2010, Mineral-PET has been the subject of intensive R&D into all aspects of the various components of the technology, and a small scale technology demonstrator has been constructed. This research has enabled the next step, where the R&D must be performed using a Mine Test Unit (MTU) at a suitable site to allow the research to continue using an upscaled unit in a real mining environment, with full integration of all technology components. The aim of this application is specifically to develop the Mineral-PET project, however, following its lifetime for R&D in a diamond mining context, the R&D will continue in other mining contexts, in border security and in biomedical contexts.
For further information, including post-grad study opportunities, please contact Prof. Simon H Connell.
The “PET” acronym is derived from Positron Emission Tomography, the well know application of nuclear imaging techniques in diagnostic medicine. As positron emission by natural carbon does not occur spontaneously, it is necessary to produce the positron emitting 11C PET isotope by the photon induced 12C(gamma,n)11C reaction. In the Mineral-PET system, there is therefore an activation stage using photons of around 23MeV which are generated by bremsstrahlung of electrons on a high-Z material. This process is carried out on the kimberlite feed rock stream which has been coarse crushed to a diameter of about 10 cm. The amount of positron emission signatures from the highly localised activated 11C in the diamonds is in very strong contrast to that of non-diamond sources of carbon which are dilutely and homogenously distributed in the kimberlite. The dominant background is from the oxygen present in the kimberlite which leads to the PET isotope 15O. The lifetime of 15O is 2 minutes compared to that of 11C which is 20 minutes, and so it is allowed to decay out in a hold hopper. The resulting rock stream can then be passed through a PET imaging system, with a modified PET algorithm optimised for on-line and real-time mineral applications. A graded high resolution ejection system can select out the diamondiferous kimberlite rocks.
There are several benefits to the implementation of Mineral-PET technolgy in cost, environmental impact and recovery of large diamonds, amongst others.
Project Concept Proposal for the SA-TCP_IAEA
*Mineral-PET : Kimberlite sorting by nuclear-medical technology - In the Proceedings of the 12th International Conference on Nuclear Reaction Mechanisms, Villa Monastero, Varenna, Italy, 15 - 19 Jun 2009, pp.589-602
- Poster presentation at the 56th Annual Conference of the SA Institute of Physics, Saint George Hotel, 12 - 15 July 2011
- Oral presentation at the 56th Annual Conference of the SA Institute of Physics, Saint George Hotel, 12 - 15 July 2011 (Prize winning Presentation for Martin Cook)