Surface Behaviour for Materials Processing

Lead Research Organisation: University of Exeter
Department Name: Camborne School of Mines


An opportunity to carry out leading edge research as part of a large international consortium researching rare earth raw materials, working in close collaboration with an exploration company developing one of the world's advanced rare earth projects.

The aim is to improve the resource efficiency of the processing flow sheet for the Songwe rare earth project in Malawi. This carbonatite deposit is being developed by Mkango Resources Ltd and has significant contents of heavy rare earth elements as well as high concentrations of neodymium.

The processing flow sheet involves flotation of the rare earth mineral synchysite and the rare earth-bearing mineral apatite, and then recovery of rare earth elements (REE) by acid leaching. The project will concentrate on improving the recovery of REE minerals by flotation by carrying out fundamental studies of the mineral properties and flotation process. Techniques that might allow recovery of valuable REE from the tailings will be sought.

Planned Impact

SoS RARE research will have an immediate economic impact by improving the prospects for the security of supply of neodymium (Nd) and the key heavy rare earth elements (HREE). The proposal has engaged six core industry partners involved in the exploration and development of new REE mines who will benefit immediately by introduction of our new exploration models and improved techniques for mineral extraction. Processing of REE raw materials is currently a major bottle neck in the value chain, and development of better methods will have an immediate impact on REE supply concerns. This will make projects more economically viable and environmentally friendly, helping to ensure a more stable supply. The four consultant company partners will gain key expertise and experience in exploration and processing which they will spread out into the wider REE mining and processing industries.

The unstable supply and cost of REE remains a major issue for manufacturers that make up a substantial part of the UK economy. A more secure supply chain will allow these manufacturers to better plan their short and long term product development. The research team will provide information on primary supplies, the likely development of future mines and how the supply chain will develop.

REE supply is a global concern. The project will have a global reach, through the industry partners involved (based in and working in the UK, Greenland, Malawi, Namibia, Spain, Canada and Australia), the core research collaborators in Germany, USA, Canada, Brazil and South Africa and wider international network links to Japan, France, and Madagascar. Diversity of supply is the key. This research proposal will place the UK as a centre in REE expertise and at the forefront of critical metals development.

The critical metals issue is requiring changes in UK Government and European Union policy, including increased support for research ion primary supplies, recycling of existing metal stocks and substitution. The impact of this research on the prospects for low environmental impact extraction of REE, diversity/security of supply and responsible sourcing will be directly relevant to future policy. The 'race' to engineer REE out of new technologies will be unnecessary and many new applications could be explored. Therefore major impact will occur at the policy level as the research guides the decision making in research funding and legislation for REE.

Few people had even heard of 'rare earths' until the issue of China restricting supply reached the news headlines in 2010, yet this family of elements are ubiquitous in digital and green technologies, from the slimmest mobile phones to giant wind turbines. We will exploit the realisation among the general public of the importance of REE towards their modern high technology life-style and demonstrate the importance of REE chemistry and geology. The REE are extremely interesting and ideal for creative and educational outputs to entertain and inform wider non-technical audiences. Encouraging the public, including school students, to learn more about REE in nature is a key part of our outreach programme.


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Owens CL (2019) Apatite enrichment by rare earth elements: A review of the effects of surface properties. in Advances in colloid and interface science

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Owens CL (2019) Surface nanobubbles on the rare earth fluorcarbonate mineral synchysite. in Journal of colloid and interface science

Studentship Projects

Project Reference Relationship Related To Start End Student Name
NE/M011429/1 01/05/2015 31/12/2019
1652549 Studentship NE/M011429/1 01/10/2015 16/07/2019 Camilla Owens
Description We have measured for the first time, the surface behaviour of the rare earth fluorcarbonate mineral parisite. We have discovered that rare earth fluorcarbonate minerals, such as synchysite, bastnasite and parisite, can be processed in the same way using froth flotation. Synchysite and parisite are possible sources of rare earth elements, which can be used in a wide range of renewable technology.
Exploitation Route Future researchers can look into our findings and apply the surface behaviour studies of bastnasite to other rare earth fluorcarbonate minerals.
Sectors Other

Title Zeta potential measurements of the fluorcarbonate mineral parisite 
Description Zeta potential measurements of the fluorcarbonate mineral parisite-(Ce), under water, supernatant and collector conditions. Zeta potential measurements can be used to indicate the surface behaviour of a mineral under different reagent conditions. Mineral surface behaviour is important in processing and extracting minerals from their host ore, which can be energy intensive. Parisite-(Ce) is a fluorcarbonate mineral which contains rare earth elements. Rare earth elements are important in a wide range of products from iPhones to wind turbines. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Impact Published research see Owens et al., 2018