Extractive Metallurgy of the Rare Earth Elements

Rare earth elements (REE) are critical materials in high-technology applications but the supply security of REEs is of major concern, the global supply chain currently being concentrated in limited areas such as China and Australia, The need to diversify the supply of these critical metals is crucial. 

The USA seems particularly concerned about supply and last month the US Geological Survey made $5M available to research critical minerals and rare earth elements found in mine waste, while other news last month suggests that Wyoming could be America’s answer to China’s lock on the market, with 2.34 billion metric tons of rare earth minerals found southwest of Wheatland by American Rare Earths Inc.

There are also significant opportunities for African countries as the African continent is endowed with some of the world’s largest REE deposits and the SAIMM's Southern African Rare Earths 2nd International Conference in Namibia in June seeks to explore the continent’s role in shaping the future of the REEs industry. 

Amanda will in Namibia, representing MEI, a media partner for the conference, and five months later MEI's Critical Minerals '24 in Cape Town will explore innovative methods and flowsheets for processing critical minerals, including REEs, from primary and secondary sources and by recycling, particularly from waste electrical and electronic equipment, the most challenging aspect in aiming for a circular economy.

The extractive metallurgy of rare earths is characterised by continual innovation, reflecting the growing applications for these critical materials in various high-tech industries. The evolution of extraction methods is driven not only by the need for efficiency but also by an increasing emphasis on environmental sustainability and geopolitical independence.

Historically, REE extraction has been a complex and environmentally intensive process. These elements are typically dispersed in low concentrations, necessitating large-scale open pit mining and extensive processing to extract them in usable forms. Commercial extraction is typically by chemical-intensive hydrometallurgical processes, posing significant environmental and technical challenges.

Much of the technology of the industry is hidden in China, the world leaders in rare earth extractive metallurgy. This leadership has developed from China rising to become the dominant supplier of rare earth raw materials from a variety of mines. Not only does China dominate the rare earth raw material supply but also the downstream processing of rare earths into a host of specialist chemical products.

Meeting rare earth demand necessitates a multi-pronged approach that encompasses not only the development of new extraction technologies but also the establishment of robust, sustainable, and geopolitically diverse supply chains. The ongoing innovation in REE extraction is a critical component of this endeavor, requiring collaborative efforts from researchers, industry stakeholders, and policymakers to ensure a sustainable and secure supply of these indispensable elements for the future

In an important keynote lecture at Critical Minerals '24, Damien Krebs, Principal Process Consultant with Primero, Australia will present an introduction to the extractive metallurgy of rare earths covering all major deposit types. The key rare earth bearing minerals will be presented and discussed from a metallurgical amenability point of view. The major processing steps will be covered in a sequential process showing the equipment and chemistry involved. 

It will be a broad presentation for a technical target audience to transfer some of the authors experience from his work in rare earths since 2010.

There is currently a call for abstracts for the conference, which immediately follows Process Mineralogy '24 at Cape Town's Vineyard Hotel, the deadline being the end of May.

#CriticalMinerals24

Mill Circuits '24 programme now available

The programme for Mill Circuits '24, which follows on from Physical Separation '24 in Cape Town is now available. This 2-day conference is sponsored by Capstone Copper, FLSmidth, and Conundrum. Our Media Partners are International Mining and Minerals Engineering, and our Industry Advocate is the Critical Minerals Association.

Jon and I will open the first day of the conference, and as this is the first of what we hope will be a new series, I will set the scene by looking at how mill circuits have evolved from the industrial revolution to the present day, and the conference will end with a panel discussion on how circuits may evolve in the future. The panel will be chaired by Dariusz Lelinski, of FLSmidth, USA, who will also present a keynote lecture on the first morning "Evolution to revolution? How can innovation in flotation technology deliver sustainable productivity, now and into the future?"

The keynote will be followed by technical presentations of either 20 or 30 minutes, the choice of the presenters. There will be much time for networking during the long coffee and lunch breaks, which will be held in the exhibition area, where there will be a small exhibition with 4 booths, one of which is still available.

We also have a new venue for the conference dinner on the first night, at Groot Constantia, South Africa's oldest wine estate, nestling under Table Mountain. 

Registration is now open, and abstract submission remains open. We look forward to seeing you at the beautiful Vineyard Hotel in June.

#MillCircuits24

2023 MEI Young Person's Award to Paulina Vallejos

We are extremely pleased to announce that the winner of the 2023 MEI Young Person's Award is Paulina Vallejos of the Universidad Técnica Federico Santa María, Chile. Paulina, who is 33 years old, was nominated by Juan Yianatos, Professor at Universidad Técnica Federico Santa María, Romke Kuyvenhoven, Member of the International Mineral Processing Council and Francisco Melo of Doña Inés de Collahuasi mining company, Chile, with support from Ahmad Hassanzadeh, of Maelgwyn Mineral Services, UK, a former MEI Award winner.

Paulina has had a brilliant career in the mineral processing area since graduating. She obtained a scholarship to study Chemical Engineering at the Federico Santa María Technical University and later obtained a scholarship to enter the graduate program because of her outstanding academic performance through her pre-graduate years. Additionally, she got a scholarship from the Chilean Ministry of Science, Technology, Knowledge, and Innovation to carry out her Master’s thesis, in which a novel methodology to estimate mineral liberation after grinding from ore deposits characteristics was developed. She graduated from the Master’s program as the Best Graduate. 

Paulina started working in mineral processing before finishing university, when she was invited to join Professor Yianatos’ team as a research assistant. Currently, she works as a researcher and project engineer, participating in numerous projects for the mining industry. Her work focuses on flotation circuit characterisation and optimisation, mineralogy studies, flotation scale-up, flotation modelling and simulation, process water characterisation in flotation and other process areas; all applied to industrial flotation circuits. Her outstanding work in mineral processing has led her to participate in several projects with many of the major mining companies in Chile and abroad, doing applied research focused on large flotation cells at industrial scale.

Between 2018 and 2022, she played an important role in a research project with the then Outotec (now Metso), leading the development of a new industrial flotation simulator for the HSC Chemistry software, using an extensive data base of experimental data from industrial flotation plants, and including novel models with respect to size-by-liberation, cells design and froth recovery per size fraction. 

In addition, Paulina is a researcher on a prestigious project, funded by the Government of Chile which has allowed her to develop research on scale-up factors for liberation-per-particle-size, applied to industrial circuits. In 2023, she worked on the application of a new research project, also funded by the Government of Chile, and will be one of the researchers on the project in the period 2024-2027, which was awarded in early 2024 with one of the highest scores in its category. The project  "Development of tools to integrate new flotation technologies in hybrid circuits, facing the challenges of the mining industry", has the main objective of the characterisation of new flotation equipment to facilitate their prompt incorporation into flotation plants. In order to do so, the project seeks to address the main challenges and contribute to the sustainable future of the mining industry. Along the same line of work, Paulina has started working on a research project with Metso (Finland) to characterise and model flotation equipment with new technologies to be incorporated in industrial plants.

Her outstanding work in mineral processing has allowed her to participate as an author and presenter in around 20 international conferences around the world, such as MEI Flotation Conferences (Flotation’17, ‘19, ’21 and ‘23), IMPC (South Africa, Russia, and Australia) and in the annual Procemin-Geomet in Chile. She is also co-author of 16 papers, published in prestigious international journals, in addition to more than 30 conferences papers. Paulina has been invited to chair technical sessions at different conferences, such as Procemin-Geomet 2019, Procemin-Geomet 2023, Flotation’23, and IMPC 2024.

Paulina with Profs. Juan Yianatos and Graeme Jameson at Flotation '23

In the period 2020-2023, Paulina worked as an expert advisor on a sustainability project with Doña Inés de Collahuasi mining company in Chile, the second largest copper mining operation in the world, focused on reducing freshwater intake through the use of seawater, including optimisation of the metallurgical performance for current and future minerals. Additionally, she worked as an expert advisor, studying the feasibility of installing new technologies for coarse particle flotation and analysing expansion plans for the same mining company. In 2017, she worked on an innovation project of this company to evaluate the installation of Jameson Cells to improve Mo recovery, which obtained successful results in practice after implementation.

Currently, Paulina is working on different projects of technical assistance for mining companies (BHP Billiton, Antofagasta Minerals, Anglo American, and others), characterising non-conventional flotation equipment to be incorporated into industrial plants, e.g., Jameson cells, SFR cells, Hydrofloat cells, and others.

The exceptional performance and expertise that Paulina has developed in recent years in research, conferences and industrial projects has led to her receiving numerous invitations and recognitions. In 2019, she was invited to join the technical committee of the international conference Procemin-Geomet, held every year in Santiago (Chile), a position that she holds to this day. In addition, she is a member of the review board of Minerals Engineering. Minerals and Mineral Processing and Extractive Metallurgy Review journals. She has also been invited as lecturer for more than 10 international training courses and technical workshops in mineral processing for the mining industry in Chile and abroad, including BHP Billiton, Metso, Glencore, Intermet Perú and the Institute of Mining Engineers of Chile. For all these activities, she has received very positive feedback from participants.

More recently, Paulina became part of the instructors’ board of Metcelerate, participating as a flotation instructor on the program in Spanish for Latin America, becoming the youngest instructor on the program. In 2023, she was selected as a member of the Academy Secondary School Research and Innovation, of the Ministry of Science, Technology, Knowledge, and Innovation of Chile, to encourage and support children and adolescents to enter the field of research and innovation. 

In addition to the awards that Paulina has obtained as a student throughout the years, in 2021, she was the recipient of the IMPC Young Author Award that is given by the International Mineral Processing Council for her outstanding research presented at IMPC 2020, the only woman among six recipients. She was highly recognized for this award in Latin America, having several interviews for different journals and newspapers. She was also invited to participate in several events, such as the annual general meeting of the Southern African Institute of Mining and Metallurgy and the 71st annual Convention of the Institute of Mining Engineers of Chile. 

In 2023, Paulina was chosen as one of the "50 genius women" of the year, an award given by the organisation Genias and sponsored by several international companies. She was selected from among more than 1000 applicants and was one of the 8 women awarded in the STEM category. This award recognises women who are generating a positive impact on our society, encouraging others to follow. Paulina has been guiding thesis students for almost 10 students and has also given presentations at schools, encouraging the secondary school students to join the mining industry, with a strong focus on women specifically, who are still a minority in this field.

It is no exageration to say that Paulina is a very worthy winner of the MEI Award, which will be presented at Process Mineralogy '24, and we look forward to following her career progression. Only last month the first MEI Award recipient, Peter Amelunxen, won the SME's prestigious Antoine Gaudin Award. Who knows, Paulina might become the first ever female recipient of this award in a few years time? A woman has never won a major award from the International Mineral Processing Council, but the gender balance is changing. The last three winners of the MEI Award have all been outstanding young women.

Physical Separation '24 programme now available

We are pleased to announce that the programme for Physical Separation '24, the 8th in the series, and the first to be held in Cape Town, is now available for viewing. The 3-day conference is sponsored by Steinert, Comex Group, Conundrum, and Capstone Copper. Our Media Partners are International Mining and Minerals Engineering, and our Industry Advocate is the Critical Minerals Association.

For the first time at an MEI Conference, authors have been given a choice of 20 or 30 minute presentation time, and the first day begins with a keynote lecture from James Agenbag, of Mineral Technologies, South Africa, who will ask "Is physical separation still relevant in 2024?" before showing why it is of critical importance.

As with all MEI Conferences, there will be plenty of time for networking, over the long coffee and lunch breaks, the evening sundowners, and the informal conference dinner at the Gold Restaurant. Coffee and lunch breaks will be in the exhibition area, where there will be 10 exhibition booths, 3 of which are still available for rental.

Registration is now open, and abstract submission remains open. We look forward to seeing you at the beautiful Vineyard Hotel in June.

#PhysicalSeparation24

Prof. Güven Önal: 1940-2024

Very sad news in from Turkey of the death, 3 days ago, of my old friend Güven Önal, mining professor at Istanbul Technical University, and President of the Turkish Mining Development Foundation. 

I have known Güven for over 37 years, since the first of the biennial Turkish International Mineral Processing Symposia, which was held in Izmir in September 1986. I had the honour of presenting the first paper and Güven was my session chairman.

Izmir, 1986, Güven is 3rd left

I last saw Güven only 5 weeks ago in Phoenix, where he was attending the SME Annual Meeting with his son Seckin Sahap Onal. Güven was a regular attendee at the SME Meetings and many other international events:

SME 2024 in Phoenix with his son Seckin Sahap

At SME '2015 in Denver:  Güven with his son Erden
and James Hendrix of Mackay School of Mines, USA

SME 2013 in Denver with Prof. Jim Finch

At Reagents' 04 in Falmouth with his wife Nese

At IMCET 2019 in Antalya, Turkey, with Diana Drinkwater and Barbara and me

Güven was a consultant to MEI's Processing of Industrial Minerals and Coal  2012 in Istanbul where we appreciated his hospitality and that of his late wife Nese

Lunch with Güven and Nese in Istanbul

Born in 1940, Güven Önal graduated from Istanbul Technical University Faculty of Mining as a Mining Engineer in 1963 and received the title of "Doctor" in 1970, "Associate Professor" in 1975 and "Professor" in 1981. He had more than 450 scientific and technological publications, including 27 books, in Turkish and foreign languages. He was a member of the Department of Ecology and Environment of the Russian Academy of Sciences and the Yugoslav Academy of Sciences, and won the University of Pittsburg Science Prize. He was the President of the Balkan Countries Mineral Processing Science and Technology Academy, and a long time Member of the Scientific and Executive Committee of the International Mineral Processing Congress (IMPC).

At Asia-Pacific 2022 in Melbourne with fellow IMPC members
Rod Elvish (Australia), outgoing chairman Cyril O'Connor (South Africa)
and incoming chairman Ralph Holmes of Australia

He was the Chairman of the 23rd International Mineral Processing Congress in Istanbul in 2006 and past Chairman of the IMPC, Prof Cyril O'Connor, of the University of Cape Town, paid this tribute:

"It is with great sadness that we have learnt of the sad and unexpected passing of our dear friend and colleague Professor Guven Onal. Guven had been hospitalized for about 3 weeks and passed away from heart failure. Guven made enormous contributions to the world of mining and minerals processing during his long and illustrious career both in academe and in industry. A graduate of the famous Istanbul Technical University he was still engaged in academic activities at the university until the present time.  He was a long-standing member of the International Mineral Processing Council having been first elected in 1997 and serving continuously since then. He will be particularly remembered for the outstanding work he did as Chair of the Organizing Committee of the XXIII IMPC Congress in Istanbul in 2006 which at that time was the largest ever Congress. 

IMPC 2006: Congress Chairman Güven (2nd left) with IMPC Council members
Cyril O'Connor, Wang Dianzuo, Doug Fuerstenau and Eric Forssberg

He also inaugurated the concept of an IMPC Regional Conference with the highly successful first in this series, viz. IMPC- Eurasia, taking place in Antalya in 2019. He was in fact already planning to organize the 2nd in the series in Antalya in 2025. At the time of his passing, he was still President of Balkan Scientific Committee and Balkan Mineral Processing Science Academy, and Vice-Chair of the Pittsburgh Coal Conference. He was also the long-standing President of the Turkish Mining Development Foundation. It is clear from all the above that his contribution to mining and minerals processing was enormous and he will be greatly missed. However much more significant for all of those who knew Guven is the memory of a wonderful friend and most gracious and generous host always accompanied until her death by his dear wife.  His hospitality was legendary and many friends and colleagues will have fond memories of times spent in Turkey as a guest of Guven.  Our deepest sympathies are extended to his two sons, their wives and his grandchildren as well to all of his colleagues at Istanbul Technical University and the organisations with which he was involved". 

Güven was one of life's gentlemen, who will be sorely missed. Our thoughts are with his two sons, Seckin Sahap and Erden and their families, who I am sure would appreciate your memories as comments on this posting.

March summary: family time

In my posting Visions of the Future I suggested that it is not too outlandish to predict that by mid-century Uber-like taxi services will be everywhere, cities, towns and villages. And it is also a fair prediction that by then all cars will be driverless. Travel would be safe and stress-free, driverless taxis whisking you to your destination, before moving to the nearest charging point to await the next call.

In this world there would be little incentive for owning a private car, with all the associated hassle of insurance, maintenance etc, and inter-city travel would be by electric trains and buses travelling on time and speedily on roads uninhibited by congestion.

A month ago I experienced this vision of the future in Phoenix. I arrived back at Heathrow on the first of the month after an 11 hour flight and the day before, while waiting for my Uber to take me to the airport I was amazed to see many driverless taxis whizz past my hotel on the way to pick up passengers. A true glimpse into the future and we are a long way off mid-century!

I met Barbara at Heathrow and we flew out to Luxembourg for a week with Jon and family. 

Luxembourg is a beautiful little country, with narrow medieval streets, castles and densely forested hills.

The 18th century Grand-Château d'Ansembourg

Overlooking Larochette,
dominated by the partly ruined 11th century Larochette Castle.

The country has a rich history, ancient and modern, and Schengen is a small wine-making village and commune in far south-eastern Luxembourg, on the western bank of the river Moselle, which has contributed to recent European history.

Due to its position near the borders of Luxembourg, France and Germany, Schengen was chosen as the symbolic location to sign the 1985 and 1990 treaties to eliminate border controls. The Schengen Agreement of 14 June 1985 provided for a progressive elimination of internal border controls and the Schengen Convention was signed on 19 June 1990 by Germany, France, and the Benelux countries Belgium, Luxembourg and the Netherlands, to allow the gradual abolition of checks at internal borders between the contracting parties.

Since 1985, other states have joined the Schengen area: Italy, Spain, Portugal, Greece, Austria, Denmark, Finland, Sweden, the Czech Republic, Estonia, Latvia, Lithuania, Hungary, Malta, Poland, Slovenia and Slovakia, as well as the non-EU members, Iceland, Norway, Switzerland and Liechtenstein.

Thanks to the single short-stay visa application, business people, tourists and other nationals can travel to each of the 26 member states of the Schengen Area with one single visa, without having to make visa applications to numerous consulates.

At the European Museum in Schengen

Although neutral, Luxembourg was occupied by the Nazis during WWII and the inhabitants suffered much deprivation, many of the young men being forcibly conscripted into the German army. There was also intense fighting, particularly in the north of the country in the Ardennes forest between Belgium and Luxembourg. The Ardennes offensive, the Battle of the Bulge, between December 1944 and January 1945 was Hitler's last throw of the dice and many of the young men killed on both sides are buried in the American and German war cemeteries outside Luxembourg city. Among the 5,074 graves in the former is that of General George Patton, who took the lead in relieving beleaguered American troups at Bastogne in Belgium during the Battle of the Bulge. He was killed in a car accident after the war, in 1945.

American and German War Cemeteries

Our week in Luxembourg gave me and Jon the opportunity to plan the programmes for Physical Separation '24 and Mill Circuits '24 in June. The latter will be the first in this series and will include a panel discussion on the future evolution of mill circuits, chaired by Dariusz Lelinski of FLSmidth, who will also present the keynote lecture.

FLSmidth is also one of the conference sponsors, and as I mentioned in my report on the Phoenix SME, they are a huge company who have been involved with MEI Conferences for many years.  The company expanded even further this month with the acquisition of the Canadian engineering company Farnell-Thompson Applied Technologies Inc., a global supplier of engineering services, parts and mills to the mining industry. The company already has a long-standing business relationship with FLSmidth, prior to the acquisition being a consulting partner providing these services to FLSmidth for many years. 

The keynote session in Phoenix was all about why net zero by 2030 is unlikely to happen and why fossil fuels such as coal and gas are going to be needed for many years yet. The British Government must have been listening, as two weeks later prime minister Rishi Sunak announced that the UK needs to build new gas-fired power stations to ensure the country's energy security, the new stations replacing existing plants, many of which are aging and will soon be retired. The government says the plans do not include measures for expensive climate change-limiting carbon capture.

Predictably the Green Alliance said it "flies in the face" of the government's promise to reach zero-carbon electricity by 2035. However the Government's approach is pragmatic, as even if an infinite number of wind turbines and solar panels were built, the reality is that they only provide energy when the weather conditions are in their favour, and in the absence of sufficient numbers of reliable and safe giant batteries fall-back options are needed. Without sufficient nuclear capacity, this means fossil fuels (see also the posting of 11th December 2023) or preferably the use of excess renewable energy on windy or sunny days to produce green hydrogen, a clean source of energy.

On a lighter note, when returning by train to Cornwall from London Paddington after our Luxembourg visit we spotted a number of Cornish Pilot Gigs in the River Tamar, which divides Cornwall from the rest of England. Looking down from Brunell's Victorian railway bridge, we were not aware that Amanda was in one of the gigs, representing one of the Helford River women's teams in the Three Rivers Race, in which 98 gigs were competing.

Amanda (right) in the Helford River gig, rowing towards the road and rail bridges
on the River Tamar between Devon and Cornwall

Amanda certainly has a knack of juggling work and family commitments with her activities. Later in the month we were at the annual Mabe pantomine, where she had, as always, a leading part.

Amanda (centre) in Mabe's in the Woods

And finally, while on the subject of family, thanks to all of you who asked of the whereabouts of my twin brother Bartholomew.  He is fine, and still working with the Bodmin Institute in Cornwall after a brief spell with MEI (posting of April 1st 2015).

With brother Bart on right (or left?)

He is currently working on evaluation of the giant underground cider lake found in East Cornwall, formed by the leaching of the mineral pommerite into the groundwater.  This lake has the potential to rival the huge cider lakes found in Somerset.