The Evolution of Mill Circuits

Mill Circuits '24 will be the first in what we hope will be an important new MEI conference series. Sponsored by Capstone Copper, FLSmidth, and Conundrum, the conference programme highlights new approaches to mineral processing circuits, through design, modelling, optimisation and operation.

I will set the scene on the opening day by showing how mill circuits have evolved from the first industrial revolution to the present day and on the final afternoon a panel will look at how they might evolve in the future.

The panel will be chaired by Dariusz Lelinski,the Global Director for Flotation with FLSmidth, USA, who will also present the first day keynote lecture  "Evolution to revolution? How can innovation in flotation technology deliver sustainable productivity, now and into the future?"

The four panelists will bring wide ranging experience into the discussion.

Kevin Galvin is well known as the inventor of the Reflux Classifier and the Reflux Flotation Cell, He is a Laureate Professor at the University of Newcastle, Australia and Fellow of the Australian Academy of Science and Australian Academy of Technology and Engineering, and previous recipient of the Antoine Gaudin Award in mineral processing. He is Director of the ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals.

Rajiv Chandramohan is Technical Director, Global Operations, with Ausenco, Canada. He has extensive experience in mineral processing research, comminution, materials handling, metallurgical testing and numerical and process simulations. He has developed a wide range of novel technologies applicable to the mining industry in gold, copper, platinum and diamond operations.

There is likely to be a revolution in process control, by harnessing physics-informed AI models for enhanced profitability, robustness, and sustainability and probably no one is better equipped to discuss this than Artem Penkin, Data Science Team Lead with AI company Conundrum, UK, who is a sponsor for all forthcoming MEI Conferences.

After graduating from Camborne School of Mines in 1985, Dave Meadows spent 12 years in production in South Africa before moving to the USA and he is now Chief Technical Officer with Bechtel Mining and Metals in Phoenix. He has wide international experience in the minerals industry, including guidance and supervision in testwork programs, process design, pre-feasibility and feasibility studies, project engineering and execution, construction, commissioning, plant optimisation and a variety of operational management roles, with involvement in significant mineral beneficiation plants for processing of base metals, precious metals and industrial minerals.

Although the panel discussion is provisionally timetabled for 90 minutes, it will last as long as the conversation flows, and if there are any topics that you feel should be discussed we invite you to submit them as comments here for the benefit of the chairman.

Mill Circuits '24 will be of great value to all involved with plant operations, and it is not too late to submit abstracts if you would like to get involved.

#MillCircuits24

All at Sea

Five years ago Barbara and I spent a week on a small vessel, island hopping along the Croatian coast (postings of 7th May and 12th May 2019), but we always said that one thing we would never do, apart from Karaoke of course, would be to spend precious holiday time on a large cruise ship. So here we are, one week into a cruise down the Iberian coast to north Africa.

Our first major cruise is taking us to places we have never been to before and what made it particularly attractive is that it sailed from, and will return to, Falmouth Docks, a 5 minute journey from home.

At 48,000 tonnes, Ambassador's Ambition is the biggest ship we have been on since we sailed from Southampton to Cape Town on the 38,000 tonnes Windsor Castle almost 55 years ago. Leaving the shelter of the English Channel we entered a gale-swept Atlantic Ocean and two days at sea with daily walks around the promenade decks to counter the great food and drinks on offer in the many bars and restaurants.

Our first port of call was Portugal's capital city, Lisbon, one of the oldest cities in the world and the second-oldest European capital city after Athens, predating other modern European capitals by centuries.

Docking in Lisbon

We walked several miles up the narrow medieval streets, reminiscent of our recent visit to Zanzibar.

From São Jorge Castle, on one of Lisbon's highest hills, the view encompasses the old city’s pastel-coloured buildings, Tagus Estuary and the Ponte 25 de Abril suspension bridge.

The mighty Spanish Armada sailed from Lisbon to England in 1588, passing our starting point of Falmouth en route to its ill-fated destiny in Plymouth at the hands of the English Admiral Sir Francis Drake and the British weather. But in April 1587 a raid by Drake occupied the harbour at the Spanish port of Cádiz for three days, capturing six ships, and destroying 31 others,an event which became known in England as 'The Singeing of the King of Spain's Beard', the attack delaying the sailing of the Armada by a year.

While Lisbon is the second oldest European capital, Cádiz, our next port, was founded 3,000 years ago by the Phoenicians and is the oldest city in Western Europe. Situated on a narrow strip of land surrounded by the sea it is a beautiful city with narrow winding alleys connecting large plazas centering on historical landmarks.

Leaving Ambition for Cádiz

Not too far from Cádiz is Gibraltar, a British Overseas Territory and city located at the southern tip of the Iberian Peninsula, on the Bay of Gibraltar, near the exit of the Mediterranean Sea into the Atlantic Ocean. The landscape is dominated by the Rock of Gibraltar, at the foot of which is a densely populated town area. 

We arrived in Gibraltar on a dull and wet early morning, but we managed to reach the top of the Rock by cable car and then walk an arduous 10 miles in the nature reserve, coming face to face with the famous Barbary Apes, originating from the Atlas Mountains in Morocco. Around 300 of these apes populate the Rock, the only wild monkey population in Europe.

Arriving in Gibraltar at dawn

And so ended an excellent first week at sea, with three more ports to call at in our second week. I look forward to sharing more experiences next week.

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