Current research areas
Froth flotation is the largest tonnage separation process by which valuable mineral particles are separated from waste rock, based on their surface properties (hydrophobicity). This process is carried out in flotation cells, in which reagents and air are added. Reagents make the valuable mineral particles hydrophobic, so they repel water. Consequently, the valuable mineral particles attach to air bubbles to form bubble-particle aggregates. These aggregates rise to the top of the cell, forming the froth phase. Waste rock remains in the slurry in the cell, known as the pulp phase. While the froth overflows as a concentrate from the top of the cell, the pulp goes out from the bottom as tailings (see image, right).
Modelling for predictive control and optimisation
As froth flotation is a large-scale process, even small improvements in separation efficiency would translate into important economic benefits and improved environmental impact. These improvements can be achieved by incorporating advanced control strategies in the process, such as Model Predictive Control (MPC). MPC has been widely considered as one of the most efficient strategies to optimise a multivariable process (such as froth flotation, which is affected by over a hundred variables). However, the implementation of MPC into this process is a major challenge as the most crucial part of this control strategy is model development.
Modelling froth flotation is a difficult task, as it has very complex dynamics as a multiphase (gas-liquid-solid) process with inherent instability. We aim to develop new, dynamic, physics-based flotation froth models for implementation as part of MPC strategies.
Fine Particle Flotation
FineFuture is an EU-funded project that aims to create new scientific knowledge to enable the development of groundbreaking technologies to exploit the fine particle fractions.
Separating very fine particles is important for the valorisation of multiple mineral resources (e.g. nickel, kaolin, feldspar, talc and magnesite) and will help secure both global sales by European companies and the production of Critical Raw Materials (CRMs) within Europe. CRMs combine raw materials of high importance to the EU economy and of high risk associated with their supply. Shortage in supply of CRMs would hinder economic growth in rapidly developing industrial areas, such as energy storage systems and industrial robotics.
To find out more please visit: https://finefuture-h2020.eu/
Advanced Heat transfer modelling
Coupled fluid dynamics (CFD) and heat transfer is a common phenomenon in many engineering problems, including electronic device cooling, furnaces and building ventilation. CFD has been widely used to model coupled problems. However, some problems involving turbulence modelling and radiative transport remain challenging.
Hydrometallurgy: Quantification and modelling of the curing and leaching of sulphide ores.
One of the key factors in leach performance is apparent leaching kinetics. These apparent kinetics are a complex function of the mass transfer within the particle and the reaction kinetics at the mineral surfaces, with this relationship being strongly influenced by the mineralogical texture of the ore and the structure of the agglomerate.
It is, therefore, possible to experimentally track this behaviour using XMT in order to improve the apparent kinetic models available. This will require the development of techniques to use a combination of XTM and MLA images, and simulation. This combination can be used to assess the likely impact of changes in the agglomerate structure on leach performance. These assessments are currently done experimentally, with the performance evaluation for each new agglomerate requiring experiments that take many months to carry out. For that reason, this would also increase the industrial relevance and usefulness of the work, leading to improvements in process design and economical estimations for mineral processing projects.
Space and Terrestrial Dry Processing
Space Resource Utilisation will be the breakthrough technology that enables the further exploration and habitation of space by humankind.
The production of oxygen on the Moon by reduction of the lunar soil is the first target for SRU, since oxygen can be used both to sustain human life and as fuel. The lunar soil must be prepared in order to provide a consistent feedstock to the reduction process. Our research explores the fundamental physical processes underpinning triboelectric charging and uses these findings to design and optimise dry processing equipment for lunar and terrestrial applications.
Multi-criteria decision-making for sustainable mining and mineral processing
Multi-criteria decision-making (MCDM) is a part of operations research that supports the decision maker to resolve problems when multiple conflicting criteria are involved and need to be evaluated. MCDM is a practical and powerful tool that may be used either under certainty or uncertainty, and that facilitates the incorporation of quantitative and qualitative analyses in a scientific manner.
Decision makers in the mining and mineral processing industry often face complex problems. Solving these problems frequently involves multidisciplinary knowledge including technical, economic, environmental and social aspects, as well as politics and regulations. Complexity arises because the decision maker must take into account the various stakeholders and also because of the uncertainty typically associated with the data. We are interested in the development of novel decision-making tools to support sustainable resource management.