Soft Sensors for Decision Making in Comminution and Classification Circuits

According to Prof. Mohsen Yahyaei, a keynote lecturer at next year's Comminution '27, modern comminution and classification circuits are increasingly constrained not by a lack of data but by limited visibility into the variables that truly matter for decision-making and optimisation. Many critical states, such as mill total and ball filling, cyclone water and mass split, and circulating load, remain difficult or impractical to measure directly and reliably online. 

Prof. Yahyaei's keynote will be an overview of model based soft sensors and dynamic circuit models developed at Australia's JKMRC and deployed at an industrial scale. Using examples from SAG, ball and vertical mills, and hydrocyclone circuits, he will illustrate how soft sensors can provide robust, interpretable estimates of internal process conditions in real time. The integration of these soft sensors with dynamic models of materials handling into control rooms and advanced control systems demonstrates how enhanced process visibility and ore tracking lead to better operational decisions, improved stability, and reduced reliance on manual measurements. The presentation will highlight lessons learned from deployment, the role of dynamic modelling in closing the loop between measurement and control, and the pathway toward more autonomous comminution circuits.

Mohsen Yahyaei is Director of the Julius Kruttschnitt Mineral Research Centre (JKMRC) at the University of Queensland. He leads research and industry partnerships spanning comminution, mineral processing, and process automation, with a focus on making grinding circuits more efficient while remaining robust to ore variability. His work combines integrated ore-to-concentrate modelling, advanced sensing and soft-sensor development, and decision-support layers that translate plant data into actionable operating strategies. Prof. Mohsen’s interests include comminution classification, model-based optimisation, and practical deployment of AI and automation in safety-critical operations. He works closely with site teams and technology partners to bridge the gap between laboratory insight, simulation, and sustained plant improvement. 

At JKMRC, he also contributes to professional training and mentoring of higher-degree researchers, translating fundamental understanding into tools that deliver measurable throughput and sustainability gains. He is active in global communication forums and promotes collaboration on benchmark data, models, and best practices. He said "This (Comminution '27) is a timely forum to challenge how we think about grinding and comminution systems, not as isolated unit operations, but as ore-driven, data-informed decision systems that must remain robust under extreme variability."

#Comminution27
#MEIBlog

February summary: Winter breaks and sad goodbyes

January had been an awful month in Cornwall with three major storms causing much devastation (January summary) so Barbara and I took ourselves off to the Spanish island of Tenerife in the first week of this month for a 10 day break in the sun and respite from the endless rain and wind.

We stayed at Los Gigantes, a small, quiet town on the west coast of the volcanic island, famous for its dramatic basalt cliffs called Acantilados de Los Gigantes, which rise 500-800 metres out of the Atlantic. To early sailors and to the island’s original inhabitants, these cliffs looked like enormous stone giants guarding the coast and Tenerife’s pre-Spanish inhabitants believed the cliffs marked the edge of the world.

Los Gigantes

Tenerife's volcanic landscape with Mount Teide, at 3715 m,
the highest point of any island in the Atlantic

Sunset over La Gomera, 15 miles from Tenerife
on the right is the Canary island of La Palma

Jon meanwhile escaped the Luxembourg winter to enjoy a few days gentle skiing with his daughter in the French Alps, before returning home for a minor leg operation, which precluded his attendance at the SME Annual Meeting in Salt Lake City, although he will be fit for April's Physical Separation '26 and Mineral Processing Circuits '26 in Cape Town.

This is the first year that I have missed the annual SME event since 2008. After 23 SME Annual Meetings I passed the baton on to Jon, but his withdrawal  meant no MEI representation this year. Hopefully Jon will be at the meeting in Denver next year.

Grandson Will continued his South American adventure. He and his girlfriend Liv, were in Peru for the first half of the month, taking in some of the famous sites

Acclimatising in Cusco

Above Machu Picchu and at 5036m on Rainbow Mountain

From Peru they flew to Canada then on to Tokyo! It's turning out to be an epic journey, so far Brazil, Paraguay, Argentina, Uruguay, Peru and Japan, with Malaysia and Indonesia next on the list.

Meanwhile Amanda has been in the county all month, enduring the endless rain, but managing to get out on the Helford River regularly to train for the upcoming World Gig Championships in the Isles of Scilly.

The passing of an old friend is always a reminder of your own mortality, and early in the month I heard the sad news that my closest friend throughout my six years at Leeds University had died at the age of 81. Bob Schofield and I shared a flat in Headingley during our undergraduate days and then we went on to spend a further three years of PhD research, after which Barbara and I took off to Zambia, and Bob and his wife Jean to Newcastle upon Tyne, where Bob spent six years with British Gas researching into the materials used for gas transmission, distribution and production. He then spent many years travelling around the world, working on major oil and gas pipeline projects in the UK, France, Netherlands and the Middle East, before becoming an independent pipeline consultant. He was still working when we met for the first time in 44 years in 2013, when he had no plans to retire. Our thoughts are with Jean and family.

Barbara and me with Bob and Jean in Leeds, 1967 and London 2013

There was also sad news of the death of pioneering mineral processor Roger Amelunxen, who I first met at Flotation '15 in Cape Town, where he and his son Peter represented their family business, conference sponsor Aminpro.

Roger and Peter (3rd and 4th left) at Flotation '15

I met Roger briefly again in Phoenix in 2024 and I am pleased that he was able to see Peter receive the SME's prestigious Antoine Gaudin Award (posting of December 22nd 2024).

Roger was 77 years old and there is little that I can add to Peter's excellent appreciation of his father on LinkedIn. Our condolences to the family.

#MEIBlog

We welcome COMEX as a sponsor of Physical Separation '26

Electronic sorting is increasingly important in mineral processing because it enables the early separation of valuable ore from waste rock, which is especially critical as ore grades decline and energy costs rise. By rejecting barren material before energy-intensive crushing and grinding, it reduces power consumption, operating costs, water and reagent use, and the volume of tailings produced, improving both economic efficiency and environmental sustainability. Advances in sensor technologies and real-time data analysis now allow accurate, high-throughput identification of mineral composition, making pre-concentration and the profitable treatment of lower-grade or more complex deposits possible.

We are pleased to have three leading players in this field as sponsors of Physical Separation '26. Steinert came in early, followed by TOMRA (posting of 21 July 2025) and our latest sponsor is Polish industrial machinery manufacturer COMEX, that develops and sells sensor-based sorting systems and powder-processing equipment for mining, processing plants, chemical operations and recycling applications. COMEX was also a sponsor of Physical Separation '24.

COMEX founder and CEO, Jacek Kolacz, said "The main reason for sponsoring the Physical Separation series is to enhance Comex Group visibility among the decision makers and mineral industry experts.  Sensor based sorting is steadily increasing in number of applications and bringing huge benefits in many aspects, so it is critical to reach the widest possible audience during the conference or the exhibition and through other news channels. It also provides more possibilities for building proper networking, which is necessary to connect with professionals and investors in a collaborative environment. Mineral processing is still the conservative area and sponsoring conferences like this one, where new technologies are well emphasized, can only help in making new complex equipment to be more common in the future".

Jacek Kolacz (centre) at Physical Separation '24

Registration is open for Physical Separation '26 and one exhibition booth is still available for rental.

Full programme details, including abstracts, can be found on the conference website and a timetable is available in pdf format.

#PhysicalSeparation26

February Cornish Mining Sundowner with visitors from far afield

A tremendous turnout last night for the February sundowner at Falmouth’s Chain Locker, helped by a welcome break in the relentless rain.

Camborne School of Mines alumni were out in force, with visitors from outside the county, and two from as far away as Malaysia and Kazakhstan.

There is usually a good student presence at the Chain Locker, as it is only a few miles from the Camborne School of Mines in Penryn.  This week, however, they were involved with other activities, as CSM has been holding an International Student Week, with Mining and Geology students from across Europe coming here to explore the School of Mines, gain insight into the projects currently underway in Cornwall and experience the overground and underground activities our region has to offer. Students have been at CSM from International Federation of Mining & Metallurgical Students member institutions in Norway, Belgium, the Netherlands and Finland. The visits have been organised by Harry McTiernan, an Engineering Geology and Geotechnics student at CSM, who provided this photo taken early in the week in Falmouth.

Welsh company Maelgwyn Mineral Services (MMS) has been involved with MEI Conferences, particularly comminution and flotation, for many years and are sponsors of next year's Comminution '27 and Flotation '27. It was great to catch up with Chairman Mike Battersby and General Manager Steve Flatman last night. They are down from Cardiff to visit GT Jones in St Austell, specialists in designing, engineering and manufacturing process equipment, to look into the manufacture of the MMS Ro-Star ultra-fine grinding laboratory and pilot mills. The USA patent has now been granted for the Ro-Star mill concept, and in conjunction with Ersel, a Turkish mill manufacturer, MMS has just completed the construction of a 500kW Ro-Star mill for an industrial application. Mike and Steve are also meeting with Cornwall based Simon Bailey, of Comminution '27 sponsor Global Met Tech, who is helping with testing and scale-up of the Ro-Star, together with advice on the best ceramic grinding media to use.

With Mike and Steve

Finally, it takes big money to start up a mine so very good news that Cornish Metals has received a non-binding Letter of Interest from the Export-Import Bank of the United States outlining potential financing support of up to US$225m for the South Crofty tin project.

The next sundowner is at the Chain Locker on Thursday March 19th, from 5.30pm.

#MEIBlog

The SME Annual Meeting in Salt Lake City is only a week away

The MEI blog began in February 2009. That same month, Jon and I attended the Society for Mining, Metallurgy and Exploration (SME) Annual Meeting in Denver, with snapshots from the event appearing in the February blog posts.

Jon and I at the Elsevier booth in Denver, 2009

The following year in Phoenix, I started writing annual reports on the SME meetings and have covered every one since, up to last year’s meeting in Denver (MINEXCHANGE 2025). That event may mark my final visit to the USA, and at next week’s Annual Meeting in Salt Lake City Jon was hoping to represent MEI, but unfortunately due to a minor operation he has had to pull out.

So I regret that there will be no MEI report and photos from this year's meeting but if you have news and photos that would be of interest to mineral processors, I would be grateful if you could pass them on. I particularly regret that we won't be able to photograph the Mineral Processing Division Award Winners this year:

Antoine Gaudin Award: Jan Cilliers
Milton E. Wadsworth Award: Ronel Kappes
Robert H. Richards Award: Rob McIvor

or the AIME's Frank Aplan Award winner James Gebhardt

The nearest I can get is photos from previous SMEs:

Jan Cilliers (2024), Ronel Kappes (2024), Rob McIvor (2022), Jim Gebhardt (2022)

Congratulations to you all. 

#MEIBlog

The crucial importance of process mineralogy

It should go without saying that all mineral processors should be interested in the mineralogy of their ore because mineralogy directly controls how the ore behaves during processing. The type of minerals present, their grain size, associations, and degree of liberation determine the choice and efficiency of comminution, separation, and extraction methods. Mineralogy influences recovery, concentrate grade, reagent consumption, energy use, and the generation of deleterious elements or penalties. A sound understanding of ore mineralogy allows processors to predict processing challenges, optimise plant design and operating conditions, and respond effectively to ore variability, ultimately improving metallurgical performance and economic outcomes.

MEI’s Process Mineralogy ’26 is important because it brings together mineral processors, mineralogists, researchers, and equipment suppliers to focus on the critical link between ore mineralogy and processing performance. The conference provides a platform to share the latest advances in process mineralogy tools, techniques, and case studies that demonstrate how detailed mineralogical understanding can solve real plant problems. By highlighting how mineralogy influences recovery, efficiency, sustainability, and risk management across the mining value chain, the conference helps bridge the gap between geology and metallurgy, supports better decision-making, and promotes more efficient, cost-effective, and environmentally responsible mineral processing operations.

Process Mineralogy ’26 is relevant to a wide range of professionals who are involved in, or influenced by, ore characterisation and processing, including:

• Mineral processing engineers and metallurgists seeking to improve recovery, grade, and plant performance.
• Process mineralogists and geometallurgists working to link mineralogical data with processing behaviour.
• Geologists and exploration professionals interested in understanding how ore characteristics affect downstream processing and project value.
• Plant operators and technical managers responsible for managing ore variability and operational risk.
• Researchers, academics, and students focused on mineral processing, mineralogy, and related disciplines.
• Equipment manufacturers and technology providers offering analytical tools, software, and processing solutions.
• Consultants and project developers involved in flowsheet design, feasibility studies, and optimisation

Process Mineralogy '26 is followed by Critical Minerals '26 and there is likely to be a fair amount of overlap between the two conferences. One of the keynotes at Process Mineralogy '26 will deal with process mineralogy for critical metals in mineral processing and extractive metallurgy and the two conferences have an advisor in common, Prof Alan R. Butcher of ButcherGeologica.

#ProcessMineralogy26
#CriticalMinerals26
#MEIBlog

Hydrometallurgy '27

Hydrometallurgy is at the heart of sustainable mineral processing, driving innovation in the recovery of critical metals, resource efficiency, and environmental responsibility. Hydrometallurgy '27 is the 2nd in the MEI series, the first being in Adelaide in 2000. It aims to bring together researchers, industry leaders, and technology developers in hydro and biohydrometallurgy, to explore the latest advances in leaching, solvent extraction, ion exchange, electrowinning, process design, and waste management. 

Dr Frank Crundwell, Director of CM Solutions Metlab, South Africa, a globally-recognised authority on mineral dissolution and leaching, has been appointed as advisory lead for the conference. "CM Solutions is delighted to contribute to this prestigious event" says Ben Knights, CM Solutions CEO. "The CM Solutions team has a reputation for its hydrometallurgy expertise, and Frank’s pioneering work has earned him international recognition. Frank’s guidance of the technical direction of this event will help contribute to the future of hydrometallurgy"

In 2021 Frank received the SME's Milton E. Wadsworth Metallurgy Award, which recognises distinguished contributions that advance understanding of the science and technology of non-ferrous chemical metallurgy and he was nominated on the basis of his work in hydrometallurgy, leaching and the development of the theory of dissolution. 

Through keynote presentations, technical sessions, and networking opportunities, participants at Hydrometallurgy '27 will gain insights into emerging technologies and the challenges and opportunities shaping the future of hydrometallurgy.

Abstracts are invited for presentation at Hydrometallurgy '27 via the online portal by December 31st 2026.

#Hydrometallurgy27
#MEIBlog

Artificial Intelligence in Mineral Processing '27

MEI's inaugural conference AI in Mineral Processing '27 is an international forum dedicated to exploring the transformative role of artificial intelligence, machine learning, and data-driven technologies in the field of mineral processing. AI is set to revolutionise mineral processing, as did the computer revolution of the 1980s.

As the global mining industry adapts to increasing demands for efficiency, safety, and environmental responsibility, AI is emerging as a key enabler of innovation. From advanced process control and real-time monitoring to ore characterisation, energy optimisation, and predictive maintenance, AI technologies are reshaping the future of mineral resource development.

The conference aims to bring together a diverse community of researchers, industry professionals, technology developers, and policy makers to:

• Present the latest research findings and industrial applications.
• Discuss challenges and opportunities in deploying AI solutions.
• Foster collaboration between academia, industry, and technology providers.
• Highlight pathways toward a more sustainable and intelligent mineral processing industry.

AI '27 will not only be a platform for sharing knowledge but also an opportunity to build networks and partnerships that will define the next generation of mineral processing technologies.

Abstracts are invited for presentation at AI in Mineral Processing  '27 via the online portal by December 31st 2026.

#MEIBlog

January summary: Storm Goretti devastates Cornwall

In my first posting of the year I said "Happy New Year to you all and let's hope it will be a better one than 2025, with less conflict and upheaval across the world."  Well, that hope flew out of the window in the first few days of 2026 and it looks like being another troublesome year on the world stage. I guess everyone has their own views on some of the outrageous things said at the World Economic Forum in Davos, Switzerland.

Here in Cornwall, we returned from mild weather conditions in the Alps at the end of December to icy conditions, with temperatures touching zero. On the 8th of the month alarms sounded on our phones with a rare red "danger to life" warning from the Government and Storm Goretti, one of the most severe storms to hit Cornwall in the last 30 to 35 years, arrived in the evening with winds of up to 99 mph. Many homes in Cornwall, including Falmouth, suffered severe damage and long power outages, but fortunately, apart from flickering lights, we escaped it. Reports suggest that tens of thousands of trees may have been blown down across the county including 80% of the trees on the iconic St. Michael's Mount at Marazion and the immense force of the wind was evident when walking around Falmouth.

Tregoniggie Woodlands, Falmouth

Falmouth Cemetery

Close on the heels of Goretti, Storm Ingrid, although not as severe, produced very heavy seas which damaged beach properties on Cornwall's south coast and disrupted train services within and out of the county.

Breach of the sea wall at Dawlish, Devon, on the London-Penzance main line
Source: BBC

The rain has been relentless and shortly after Ingrid moved on Storm Chandra brought more torrential rain, disruption and flooding. 

New MEI recruit Will missed all this, as he had taken off for warmer climes, flying to Rio for travels in South America with his friend Sam. While in Brazil they managed to see the Iguasu Falls, arguably the most impressive falls in the world (posting of 1st August 2016), Will favouring the Brazilian rather than the Argentinian side of the Falls.

After travelling through Paraguay they enjoyed Buenos Aires, where they were joined by Will's girlfriend, Liv, before moving on to Uruguay. Will resumes his apprenticeship with MEI on his return and hopefully you will see him with Amanda and me at the Cape Town IMPC in October.

#MEIBlog

A second Lifetime Achievement Award for Prof. Jim Finch

I was more than pleased to hear that my old friend Jim Finch received the Canadian Mineral Processors' Lifetime Achievement Award at the CMP Annual Meeting last week in Ottawa. In 2020 he was the recipient of the Lifetime Achievement Award of the International Mineral Processing Council.

Jim with McGill's Associate Professor Kristian Waters

With current and former graduate students of McGill University 

I have known Jim since 1986 when he attended the NATO Advanced Study Institute in Falmouth and in 2015 he was the subject of one of my interviews with leading mineral processors.

Jim had an illustrious career at McGill University, where he is now, after retirement, an Emeritus Professor, and did much to rank the University highly in the mineral processing field. As well as authoring over 300 journal articles he was co-author of the seminal book Column Flotation, with former student Glenn Dobby.

With Jim and Glenn in Cornwall in 1988

I am particularly proud of the fact that Jim agreed to work with me on Mineral Processing Technology, which was published as an 8th edition in 2016, a busy year for Jim as he was Chair of the International Mineral Processing Congress in Quebec.

Book signing in Phoenix, 2016

Opening IMPC 2016 in Quebec

Jim has had a big involvement with MEI. In 2015 he became a consultant to MEI's Flotation Conferences on the retirement of Prof. J-P Franzidis and  has proven to be a huge asset, advising on the technical programme and judging student presentations with his wife Lois, as well as presenting three keynote lectures over the years.

Jim and J-P Franzidis at Flotation '15

Jim actively involved with Flotation '23 and '25

Jim with fellow Antoine Gaudin Award winners, Jan Cilliers,
Kevin Galvin and Osvaldo Bascur at Flotation '25

Congratulations Jim from all at MEI. Nobody deserves this award more than you.

Jim and Lois with Barbara Wills at Flotation '11

#MEIBlog

Advancing the Minerals Industry Through Collaboration: Capstone Copper and Promet101

Capstone Copper Corp. is a Vancouver-based Canadian mining company focused on copper production across the Americas. It was created in March 2022 through the merger of Capstone Mining and Mantos Copper, combining their assets and operations into a larger, diversified copper producer and has grown into a notable mid-tier copper producer with operations in Chile, Mexico, and the United States.

In 2024, the company produced roughly 184,000 tonnes of copper and Capstone is working toward becoming a 400,000 tonne annual copper producer over the next few years through organic growth and expansions.

Capstone emphasises responsible and sustainable mining, aiming to positively impact its employees, communities, and environments around its operations. Its sustainability reporting highlights efforts in responsible business practices and community engagement.

Peter Amelunxen joined Capstone in April 2022 as Vice President, Technical Services and was promoted to Senior Vice President, Technical Services in August 2023. Peter was the first recipient of the MEI Young Person's Award back in 2011 and in 2024 he received one of the SME's highest honours, the Antoine Gaudin Award.

Capstone was a sponsor of Flotation '25 and at the conference we were very pleased to hear from Peter that the company had agreed to sponsor not only Flotation '27 but also all 2026 conferences and Comminution '27.

Peter Amelunxen with MEI's Jon

Peter said: "In a world of rapidly rising demand for raw materials, we can’t rely solely on mining our legacy, high grade ore bodies. The next generation of successful mining companies are going to be those that embrace technology and innovation in a way that is measured, reliable, and prudent. Capstone Copper intends to be one of them, and that’s why we sponsor MEI Conferences. This conference series brings together the world’s most experienced and respected technical experts and puts them in a setting where they can freely share ideas, talk about their problems, and discuss solutions. Compared with other conferences, the signal to noise is extremely high, and I have never attended an MEI conference without having learned something brand new (to me), hired a rock star, or come away with a great new idea for our business. Sponsoring MEI is not just our way of saying thanks; it’s also a good Corporate Social Responsibility practice and excellent return on investment".

Promet101 has also become a strong supporter, and has agreed to sponsor all 2026 MEI Conferences, and AI in Mineral Processing '27 and Flotation '27 in the following year. Founded by CEO Stuart Saich, Promet 101 is an international company, headquartered in Australia, with offices in Canada and Chile, whose objectives are to provide sound solutions to clients' requirements and ensure that a well-documented path from ore definition, metallurgical testing programs through to process design criteria is provided for subsequent scrutiny by third parties such as engineering entities engaged to complete detail designs or peer reviews for project financing.

Stuart Saich with MEI's Jon

In 2023 Stuart said "So why does a small company like ours continue to support MEI through good and tough times. Well if you think carefully about it, how much effort is put into developing a technical paper. 100 or 200 hours per paper? Then what about the costs involved? By supporting MEI you are supporting a platform for the advancement of our own industry by willing individuals to advance the scientific knowledge of the very industry we belong to. What is the inherent intellectual value or investment into the knowledge base of each conference at which say 100 technical papers are presented? I would say $1-2 million a piece. And from that investment springs further value growth as ideas advance and commercialisation grows. Why do we invest in supporting MEI every year, because it makes absolute sense! It is not about me, it is about our industry!"

Many thanks Capstone and Promet101, we greatly appreciate your ongoing support.

#MEIBlog

The Processing Challenge Behind the Critical Minerals Boom

Critical minerals underpin the technologies driving the next wave of industrial transformation, from AI data centres and electrified transport to renewable energy and defence systems. But while demand is accelerating, mineral processing capacity and supply diversification are struggling to keep pace. For mineral processing this widening gap presents both risk and opportunity.

Between 2024 and 2040, global demand for critical minerals such as copper, lithium, nickel, cobalt, graphite, and rare earth elements (REEs) is forecast to grow 1.5 times, from 35 million tonnes to over 52 million tonnes. This surge reflects the material intensity of the technologies powering decarbonisation and digitisation. Electric vehicles alone can require up to six times more minerals than internal combustion engine vehicles, including over twice the copper content. Likewise, renewable power systems, particularly wind and solar, are far more mineral-intensive than natural gas-fired plants.

By 2040, clean-tech applications could represent over 40% of total mineral demand, up from around 25% today. As grid-scale storage, electric transport, and AI infrastructure expand, copper, lithium, and REEs will be among the most strategically significant feedstocks. The question for mineral processors is whether the industry can scale up efficiently enough to meet these demands without compromising environmental or economic viability.

While new exploration and mining projects are essential, a recent report speculates that a major supply of critical minerals may be hiding in plain sight in many metals mines. Researchers found that U.S. metal mines already contain large amounts of critical minerals that are mostly going unused. Recovering even a small fraction of these byproducts could sharply reduce dependence on imports for materials essential to clean energy and advanced technology. In many cases, the value of these recovered minerals could exceed the value of the mines’ primary products. The findings point to a surprisingly simple way to boost domestic supply without opening new mines.

For copper, ore grade decline is already eroding output efficiency. Even as demand continues to climb, mined supply could peak before 2030, leading to a projected 33% gap between supply and demand by 2035. This places immense pressure on concentrators and smelters to extract more from lower-grade ores while maintaining recovery rates and controlling energy use. Advanced flotation chemistry, sensor-based ore sorting, and hydrometallurgical innovations may play a critical role in sustaining output.  MEI’s Process Mineralogy’26 aims to address some of these aspects from a mineralogical and geometallurgical perspective.  

Lithium processing faces similar constraints. While new spodumene and brine projects are emerging, the step from raw concentrate to battery-grade lithium carbonate or hydroxide remains a key limiting factor. Global lithium demand could rise from 1.2 million metric tons of lithium carbonate equivalent (LCE) in 2024 to as much as 3.3 million by 2030, with a potential 38% shortfall by 2035. Expanding refining and conversion capacity, especially outside China, is now central to supply security.

REEs are another case study in processing dependency. Although geologically abundant, they are technically challenging to separate and refine due to their similar chemical properties and environmental management requirements. China currently dominates 91% of REE refining and 94% of magnet manufacturing. Recent export restrictions on REE magnets and materials have further highlighted the risks of single-country dependency, underscoring the need for alternative processing hubs and cleaner extraction technologies. The graphic below shows Europe's dependence on China for its supply of critical minerals

China's dominance on critical minerals supply to Europe
Source: Visual Capitalist

And the graphic below shows China's share of global production of critical minerals

Source: Visual Capitalist

There are other causes for concern. South Africa, for instance,  produces 37% of the world's manganese but its last remaining manganese smelting operation is at risk of closure as surging electricity costs continue to batter energy-intensive industries, raising fresh concerns over job losses and the country’s industrial competitiveness.

As these challenges intensify, forums for technical collaboration and knowledge exchange are becoming vital. Events such as MEI’s Critical Minerals ’26: Processing and Recycling play a crucial role in uniting researchers, plant operators, technology developers, and policymakers to address precisely these bottlenecks. By spotlighting advances in beneficiation, hydrometallurgy, and recycling, the conference provides a global platform for developing the next generation of processing solutions essential to secure, sustainable mineral supply chains.

Alongside new mining and processing projects, recycling of critical minerals is emerging as an essential but underdeveloped pillar of supply. Recovering valuable elements from end-of-life batteries, electronics, and renewable infrastructure could reduce dependency on virgin mining and help close material loops.

However, recycling critical minerals presents unique metallurgical challenges. Many technologies, such as lithium-ion batteries and permanent magnets, are designed for performance rather than disassembly. Materials are often tightly bonded, chemically complex, or present in trace quantities, making recovery inefficient with conventional processes. For example, lithium recovery from spent batteries remains below 50% in most current hydrometallurgical flowsheets, and separation of REEs from magnet alloys is both energy- and reagent-intensive.

Developing economically viable recycling processes will require the same level of metallurgical innovation seen in primary production. Pyro- and hydro-metallurgical hybrid approaches, selective leaching, and solvent extraction tailored to complex feedstocks are all areas of active research. For processors, integrating recycled feed into existing smelters or refineries could become a strategic advantage, helping balance supply while reducing the carbon footprint of production.

Critical Minerals ’26 is set to be a focal point for this kind of innovation, highlighting not only advances in recycling flowsheets but also the integration of secondary materials into conventional processing infrastructure. As recycling becomes an indispensable component of supply chain resilience, the discussions and case studies shared at the conference are expected to influence both industry strategy and policy direction.

Governments are increasingly aware that processing, not just mining, determines strategic autonomy. The race to electrify and digitise the global economy begins, and could stall, at the processing stage. Without sufficient refining, conversion, and recycling capacity, even the most promising ore bodies will not translate into resilient supply chains for batteries, power grids, or AI infrastructure.

For mineral processors, this decade represents a defining moment. Expanding global capacity, improving recovery efficiencies, and developing circular, lower-impact processing routes will determine not just profitability but the pace of the energy transition itself. As the sector seeks pathways forward, Critical Minerals ’26 stands as a pivotal forum for collaboration, bridging research and practice to accelerate the innovations that will define the future of critical mineral processing.

#CriticalMinerals26
#MEIBlog

January Cornish Mining Sundowner

It was good to see so many at last night's sundowner at the County Arms Hotel in Truro.

There were a few new faces and I was particularly pleased to see Penny Davies at her first sundowner. Penny is the partner of Dean Eastbury, by far the best of the many Elsevier Executive Publishing Managers who worked with me on my time as Editor-in-Chief of Minerals Engineering. Dean is now retired in Hayle, three train station stops from Truro and is a regular sundowner attendee.

Penny and Dean (centre) with Barbara and me

There was good news this month that one of our fairly regular attendees at the sundowners, Frances Wall, Professor of Applied Mineralogy at Camborne School of Mines and one of the world’s foremost experts on critical minerals and mining, has been awarded an OBE for services to Geoscience and Sustainable Resource Development in the King's New Year's Honours List.

Frances is a former Head of CSM, currently leading and taking part in large research projects on technology metals, circular economy, digital transformation and regional development, as well as teaching geology and mining and serving in various roles such as chair of the British Geological Survey Science Advisory Committee, trustee of the CSM Trust, Cornish Institute of Engineers and the Royal Geological Society of Cornwall. She was recipient of the William Smith Medal of the Geological Society in 2019 and nominated one of the 100 Global Inspiration Women in Mining 2016. In 2018 she presented a keynote lecture at MEI's Process Mineralogy '18 in Cape Town. Congratulations, Frances on behalf of us all.

Frances Wall (left) at Process Mineralogy '18

On Tuesday,there was a meeting on Cornish critical minerals at No. 10 Downing Street with the Prime Minister’s Economic Advisor for Business and Trade.  The meeting covered the importance of Cornwall for critical minerals projects and highlighted the tin/ tungsten/ lithium opportunities. Cornish Lithium's Jeremy Wrathall highlighted the lithium opportunity, alongside Fawzi Hanano, Cornish Metals plc for tin and Dennis Rowland, Cornwall Resources Limited for tungsten. Industry association representatives Ola Zawalna, of Cornwall Mining and Geo-Resources Alliance and Kirsty Benham of the Critical Minerals Association (UK) attended on behalf of the wider industry, including Imerys British Lithium Ltd, Tungsten West plc, Cornish Tin Ltd and Geothermal Engineering Ltd. 

The meeting was another positive development in UK Government support for the critical minerals sector, which needs engagement at the highest levels of government to ensure UK global competitiveness in the critical minerals space and grow the businesses that will help to secure critical mineral supply chains domestically and alongside partner nations. 

We are back at Falmouth's Chain Locker for the next sundowner, on Thursday February 19th, from 5.30pm.

#MEIBlog

Looking Ahead to April: MEI’s First Conferences of the Year in Cape Town

MEI’s first conferences of the year are now just three months away, and we look forward to two outstanding events at Cape Town’s beautiful Vineyard Hotel.

Physical Separation ’26, the ninth conference in this successful series, is sponsored by Promet101, Gravity Mining, Steinert, TOMRA, Capstone Copper, and Mineral Technologies.

The conference will open with a keynote lecture, "Back to the future: the resurgence of physical separations", presented by Dr. Kristian Waters of McGill University, Canada. This will be followed by 36 technical presentations covering sorting, gravity, magnetic, high-tension and tribo-electrostatic separation, hydrocyclones, and industrial screening.

The full programme is available on the website, with links to abstracts and speaker biodetails. The conference timetable can also be downloaded as a pdf.

The conference dinner will take place at the nearby Kirstenbosch Botanical Gardens, widely acclaimed as one of the world’s great botanical gardens. Few venues can rival the sheer grandeur of Kirstenbosch, set against the eastern slopes of Cape Town’s iconic Table Mountain.

Immediately following Physical Separation ’26 is Mineral Processing Circuits ’26, sponsored by Promet101 and Capstone Copper. Media partners for both conferences are International Mining and Minerals Engineering.

The opening keynote, "A new paradigm for mineral processing circuits: what might underpin the philosophy?", will be delivered by Kevin Galvin, Laureate Professor and Director of the ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals at the University of Newcastle, Australia. Kevin is well known as the inventor of the Reflux Classifier and Reflux Flotation Cell, and more recently the CoarseAir flotation cell.

Following the keynote, the conference will feature 31 presentations delivered over two days. The full programme and abstracts are available on the website, and the timetable can be downloaded as a pdf.

A new venue has been chosen for the conference dinner: The Wild Fig Restaurant, an 18th-century farmhouse nestled in the shadow of Table Mountain.

We look forward to welcoming delegates to what promises to be an outstanding week of conferences in Cape Town. Together they promise an engaging week of technical discussion, networking, and exceptional surroundings..

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