Real-time Fluorine Mineral Detection using Novel Fluorescence Technology
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Date
2022
Authors
Teixeira, Lewis D Silva
Editors
Advisors
Spooner, Nigel
Tsiminis, Georgios
Tsiminis, Georgios
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Thesis
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Abstract
As the demand for minerals necessary for a clean-energy future continue to grow, it is essential that the mining industry can meet this demand. However, elemental grades of the critical minerals that enable this future are depleting globally, resulting in processing greater quantities of material for diminishing returns. This processed material includes additional deleterious by-products that cause environmental or physiological harm. The element fluorine, with its capacity chemically to readily react with other elements to form hazardous by-products is such an example that will continue to grow in impact. Discoveries that occur in research laboratories provide opportunities to advance or revolutionise existing processes or techniques in any industry. The challenges for mining and mineral processing is to discover, then translate the discovery in the lab into something practical for real-world use, or to successfully expand a process to operate at a large scale. Key improvements include new techniques to mine and process lower grade ore, to use less energy and water, produce less carbon and tailings pollution, and to access material currently below commercially-feasible extraction grades. This thesis describes the development of a novel real-time fluorine mineral sensor for application on mine sites where fluorite and/or fluorapatite are an issue. It begins by validating newly-discovered NIR fluorescence emission signals obtained using laser sources, and identifying the optimal excitation wavelengths to form the basis for constructing a prototype of a practical sensor. Next, this basic prototype is tested to verify that the emission spectra can be observed from excitation with LED sources, dramatically lowering the component costs. Then, construction and experimental testing of a full-scale prototype system is undertaken. Using photodetectors to detect NIR emission, the system was able to detect an average linear voltage response with respect to fluorine grade, demonstrating proof of concept, however the uncertainty associated with each grade overlapped with the error between the other grades, rendering mineral specificity problematic with this design, and pointing to the need to redesign the prototype for improved SNR. Suggestions on how to improve measurement sensitivity and construction are then given as methods to reduce uncertainty and improve prototype performance.
School/Discipline
School of Physics, Chemistry and Earth Sciences
Dissertation Note
Thesis (MPhil) -- University of Adelaide, School of Physics, Chemistry and Earth Sciences, 2022
Provenance
This thesis is currently under Embargo and not available.