Francois specialises in the modelling and simulation of flotation circuits and has helped develop a new paradigm in the integrated forecasting of the processing behaviour of ores using mineralogy and ore particle textural attributes.

Francois’ research is primarily focused on the efficient and cost-effective recovery of valuable minerals through froth flotation. His PhD thesis focused on the measurement and quantification of exposed hydrophobic mineral grain textural features in composite particles and how these attributes affect our ability to predict their flotation performance. His research in this area has now expanded to include the integrated modelling and simulation of mineral processing circuits through the development and application of a better understanding of property-based approaches. The development and application of selective flotation surfactants are an important part of his research in this regard.

Aside from his experience in the modelling and simulation of process circuits, Francois has also been involved in the application of a small-scale test designed to quantify flotation separability in the context of geometallurgical modelling. This work demonstrated the power of this small-scale test to accurately forecasting the recovery potential of target minerals from very small sample quantities, making it a highly suitable device for characterising the flotation separability of small, and hence less variable, ore samples. A method was also developed by which this small-scale device can be used to compare the metallurgical performance (concentrate grade, mineral recovery and mass recovery) of different samples and allows for the classification of samples into geometallurgical domains with similar separability.

Francois is an early career researcher with the Julius Kruttschnitt Mineral Research Centre (JKMRC). After receiving a Bachelor of Engineering (Chemical Engineering Specialising in Mineral Processing) from the University of Potchefstroom (South Africa) in 2003, he started his career as a metallurgist working for the world's second largest Platinum Group Metal producer while continuing part-time postgrad studies and completed a Masters in Metallurgical Engineering (with Honours) from the University of Pretoria (South Africa) in 2007. After nearly five years in the PGM industry, Francois relocated to Perth, Western Australia where he was involved in process engineering and design studies for a large Cu/Mo operation in Papua New Guinea. As a process engineer, Francois also expanded his commodity experience by being involved in process engineering test work for iron ore operations. Through his involvement in the analysis of metallurgical and geological test results as a process engineer, he gained significant insights into the important ore characteristics that drive the design of process plants.

He then joined The University of Queensland in 2012 and commenced a Doctor of Philosophy in Mineral Processing which was conferred in 2017. His thesis lead towards a better understanding of the flotation behaviour of composite particles and provided new insights on how the link between the geology of the ore, at different length scales, and downstream flotation which is affected by textural features at the micron scale, can be strengthened in the future.

Francois has more than 13 years of experience in Mineral Processing and has gained a deep understanding of the interdependency of the activities across the mining value chain. His research and interests, therefore strongly align with developing processes and tools that will help the extractives industry better quantify opportunity, and reduce business risks.

Industry Engagement

After graduation, Francois commenced his career in mineral processing working as a plant metallurgist for the world's second largest Platinum Group Metal producer in South Africa. Here he became intimately involved in the characterisation of the distribution of the value-bearing minerals in the flotation feed ores and a key focus of his work was to understand the implications of the ore types on the types of gangue and valuable minerals present and how flotation chemistry could be used to manipulate flotation metallurgy, which was the topic of his Masters’ Thesis. Francois is currently involved in a number of research projects with industry partners of whom the AMIRA P9Q project is the largest with various mining houses and mining equipment, technology and services (METS) companies as sponsors. Francois is also undertaking one-on-one research projects with mining companies to solve specific challenges. He has also been part of industry Metskill training courses and through his regular interactions with site personnel, participates in research outcomes technology transfer to ensure sponsors have access to the latest research tools and methods.

Collaborations

Through his research Francois has developed a strong collaboration with researchers from The University of Queensland but also with researchers at international institutions that include The University of Cape Town (South Africa), The University of Utah (USA), Federal University of Rio de Janeiro (Brazil), Chalmers University (Sweden) and Hacettepe University (Turkey). He has also recently been invited to present a course on Flotation and Geometallurgy at The University of Liege, Belgium where he will be joined by a panel of world experts on this topic.

Key Publications

Miller, J. D., Li, J., Davidz, J. C. and Vos, F. (2005). A review of pyrrhotite flotation chemistry in the processing of PGM ores. In: Barry A. Wills, Selected papers from Precious Metals ’04. Precious Metals 2004 Conference, Cape Town, South Africa, (855-865). 10-12 November 2004. doi:10.1016/j.mineng.2005.02.011.

Yahyaei, M., Vos, F., Powell, M., Siliezar, J. and Perkins, T. (2014). Challenges in developing integrated process models based on industrial survey data. In: 12th AusImm Mill Operators' Conference 2014: Proceedings. 12th AusIMM Mill Operators' Conference 2014, Townsville, Australia, (437-446). 1-3 September 2014.

Vos, Cornelius and Bradshaw, Deirdre (2014). Characterizing flotation recovery variability of copper ores. In: Juan Yianatos, XXVIl International Mineral Processing Congress - IMPC 2014: Conference Proceedings. XXVII International Mineral Processing Congress - IMPC 2014, Santiago, Chile, (43-52). 20-24 October 2014.

Wang L., Runge, K., Peng, Y. and Vos, C. (2016) An empirical model for the degree of entrainment in froth flotation based on particle size and density. Minerals Engineering, 98 187-193. doi:10.1016/j.mineng.2016.08.025.

Vos, Cornelius Francois (2017). The effect of mineral grain textures at particle surfaces on flotation response PhD Thesis, Sustainable Minerals Institute, The University of Queensland. doi:10.14264/uql.2017.326.

Full list of publications available on espace

Funding

  • Integrated Extraction Simulator Development
  • AMIRA P9P: The optimisation of mineral processing by modelling and simulation 2012-2015
  • Evaluation of TTC based collectors for improved flotation of regrind mill