September summary: London, Luxembourg and France

I’m sure that everyone over a certain age will remember what they were doing on September 11th, 25 years ago. Barbara, Amanda and I were preparing to fly to Vancouver for MEI’s Minerals Engineering ’01, which was scheduled to begin on September 16th. The conference was organised in collaboration with the University of British Columbia, and later that fateful day we received a call from our UBC contact, Prof. John Meech (obituary 22 February 2015), advising us that we would have to cancel, as all North American airports had been closed for the foreseeable future.

It was a truly horrendous day, and thankfully there has been nothing remotely comparable in terms of terrorism  and its wider impact. The closest we have come, in terms of the disruption to international air travel, was in 2010, when the eruption of the Eyjafjallajökull volcano in Iceland led to the cancellation of flights across Europe and beyond from April 15th, just three days after the start of Comminution ’10. In contrast to 9/11, however, this was a natural event rather than a human-induced tragedy, and the consequences for us were largely logistical. As all the delegates had already arrived in Cape Town, there was no disruption to the conference itself, although many were stranded for a few days afterwards.

Amanda and Jon obviously devastated to be stranded in Cape Town

In September last year Amanda was in London for the Great River Race, a spectacular boat race covering 21.6 miles (35 km) from Millwall in the East to Richmond in the West, passing under London’s famous bridges over the Thames (posting of 29 September 2026). She was back again last month competing with a crew of normally social (rather than competitive) rowers in their beautiful traditional Cornish gig, Helford. It was a "fun" three and a half hours, said Amanda,  who this year, shared the coxing, giving up her seat as the stroke rower halfway through the race in order to cox the crew to the finish line.

Flying the Cornish flag in London and Luxembourg

As old age continues to gently erode my days as an action man, I’m now content to enjoy adventures vicariously, watching the next two generations take up the baton.

These days, 20 km on my e-bike is about my limit, and I’m increasingly grateful for electric assistance, but tucked away in the memory banks are some very happy years of squash, weightlifting, scuba diving, skiing, windsurfing, rugby and hiking mountains. Looking back, I realise how fortunate I was to have enjoyed so many active adventures  and perhaps even more fortunate now to see the enthusiasm being passed on to other generations. I may no longer be leading from the front, but it’s rather nice to be enjoying the view from behind.

Later in the month Barbara and I caught up with Jon and family in Luxembourg. We are getting to know this beautiful small country well and its neighbouring countries of Belgium, Germany and France.

Last year we crossed the north Luxembourg border into Belgium and visited the small town of Bastogne, a strategic town in WW2's Battle of the Bulge (posting of 29 May 2025).

This September we spent a few hours 30 miles from Bastogne in the Luxembourg town of Clervaux , which played an important role in the Battle of the Bulge in December 1944.

Clervaux

German forces launched their surprise offensive through the Ardennes and attacked Clervaux on 16 December 1944. A small group of U.S. soldiers defended Clervaux Castle against a much larger German force. The Americans held out for roughly two days, delaying the German advance. Most of the defenders were eventually captured or killed, and the town was taken by German forces.

During the fighting, Clervaux Castle, which dates back to the 12th century,  was badly damaged, but it was later carefully restored. It now houses museums and exhibitions that tell the story of Clervaux and its wartime history.

Clervaux Castle, 1945 and 2026

In the town, a GI statue and a preserved Sherman tank provide further reminders of the fierce fighting and of Clervaux’s appreciation for the American soldiers who helped liberate Luxembourg during the Second World War.

On our first visit to Luxembourg we had the bizarre experience of walking down the main shopping precinct at Esch-sur-Alzette with two giant blast furnaces towering over the shops and cafes (posting of 1st February 2023).  Instead of demolishing everything, Luxembourg preserved the furnaces as industrial heritage and last month we ascended the 250 steps up to the charging section of one of the furnaces, which was shut down in 1965. On the way we passed the massive machinery and structures that were involved in producing pig iron.

The tuyeres which introduced the blast of hot air into the furnace 

We crossed Luxembourg's southern border into France to spend a couple of nights in Strasbourg, a beautiful city in north eastern France on the German border. It is one of the main seats of European institutions, including the European Parliament, the Council of Europe, and the European Court of Human Rights. 

The city is dominated by the enormous Gothic cathedral and photographs do not convey its gigantic and impressive size. Construction began around 1015, with the present Gothic cathedral developing from the 13th century onward and the famous spire completed in 1439.  The spire rises 142 metres and for centuries, it was among the tallest buildings in the world.

Petite France is probably the most picturesque part of Strasbourg. It’s a historic neighborhood on the Grande Île, the island at the heart of the city, and is famous for its canals, half-timbered houses dating from 16th and 17th centuries, bridges and narrow cobbled streets.

While we were in Strasbourg, Amanda was also in France, about 340 miles away in Orléans, where she was representing MEI at the International Biohydrometallurgy Symposium (IBS 2026). We will publish a summary of the conference next week.

Amanda and one of her Helford Rowing Club friends in Orléans, prior to IBS '26

And now we are back in Cornwall. But not for long- in two weeks time we will be on our way to Cape Town for the International Mineral Processing Congress, followed three weeks later by MEI's Process Mineralogy '26 and Critical Minerals '26.

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What might we expect at Comminution ’27?

When the 14th International Comminution Symposium, Comminution ’25, gathered in Cape Town last year the mood was unmistakably one of transition. The fundamentals of crushing and grinding had, of course, not changed. Rock still has to be broken, energy is still required to break it, and the perennial challenges of wear, throughput, liberation and classification remained firmly on the agenda.

But there was a noticeable shift in the questions being asked. How can we make comminution more selective rather than simply finer? How can sensors tell us what is happening inside a mill before the operator can see the consequences? Can artificial intelligence replace some of the expensive and time-consuming conventional characterisation work? And perhaps most importantly, how do we design a circuit around the whole value chain rather than optimising individual pieces of equipment?

As we look ahead to Comminution ’27, these questions are likely to become even more prominent. So what might have changed between the presentations at Comminution ’25 and Comminution ’27?

Artificial intelligence was already impossible to ignore at Comminution ’25. The opening keynote examined how rapidly developing AI techniques were accelerating comminution modelling, while other presentations explored machine learning for mill optimisation, AI-assisted calibration, soft sensors and model-predictive control. One particularly practical example was work using machine learning to predict standard comminution parameters from Geopyörä breakage-test data.

At Comminution ’25, AI was often presented as a promising addition to existing modelling and control methods. By Comminution ’27, we may see much more emphasis on AI embedded in the workflow. That could mean AI-assisted ore characterisation, rapid geometallurgical variability assessment, real-time soft sensors, predictive control and automated optimisation. 

Another strong thread from Comminution ’25 was the rapid development of indirect ways of seeing what is happening inside equipment. Acoustic monitoring was one example. Research presented at the conference investigated how changes in AG/SAG mill feed size produced distinctive acoustic responses. Similarly, the conference included work on instrumentation and analytics for cone crushers, including the integration of noise, vibration, high-frequency monitoring and vision systems for fault detection and condition monitoring. Since the conference, the same direction has continued into fine grinding. This is significant, as for decades operators have had to infer what is happening inside a mill from measurements taken around it: power draw, pressure, density, flowrate, product size and so on. The next generation of systems may make the equipment itself an increasingly sophisticated sensor. At Comminution ’27, expect more work combining acoustic, vibration, power, pressure, vision and process data and turning those signals into information that operators can actually use.

Perhaps the most important evolution since Comminution ’25 is occurring at flowsheet level. There were already strong signs of this in Cape Town. One study presented a framework for integrated optimisation of crushing, milling and cyclone classification, explicitly considering throughput and product quality together. Another proposed a “Parallel Flow Sheet” incorporating HPGR, stirred milling and classification.

At the same time, HPGR was being considered not simply as a more energy-efficient piece of equipment, but as part of fundamentally different circuit architectures. This is a crucial distinction. For many years, comminution innovation could be discussed in terms of better crushers, better mills, better liners or better grinding media. Increasingly, the question is becoming: what is the best sequence of breakage, classification and separation operations for the ore?

That opens the door to circuits that might look very different from the conventional crushing–SAG–ball mill–flotation arrangement.  HPGR, stirred mills, dry classification, coarse particle recovery and sensor-based sorting can all become parts of the same optimisation problem. Comminution ’27 could therefore be considerably more about flowsheet architecture than equipment optimisation in isolation.

“How fine do we really need to grind?” This may ultimately be one of the biggest questions of the next decade. The conventional response to poor liberation has often been to grind finer. But finer grinding comes with a price: energy, media consumption, wear, water consumption and, potentially, the generation of fines that are difficult to recover. Comminution ’25 highlighted this tension repeatedly. There was discussion of the balance between improved liberation and fines generation, dry grinding, coarse gangue rejection, HPGR-based circuits, sensor-based sorting and alternative comminution technologies. The implication is that the optimum comminution product may not be the finest product. It may be the product that gives the best combination of liberation, particle size, shape and downstream recoverability.

That moves comminution much closer to the heart of the entire mineral-processing value proposition. This leads naturally to another likely feature of Comminution ’27: increasing interest in selectivity.

Traditional comminution is largely indiscriminate. The objective is to reduce particle size, while liberation is a consequence of the breakage process. But mineralogical information increasingly allows us to ask whether rocks can be broken preferentially along mineral boundaries, or whether valuable minerals can be liberated without unnecessarily grinding barren gangue. Comminution ’25 contained several examples of this philosophy, from high-voltage pulse power and HPGR to GRolls and mineralogical investigations of breakage.

The subsequent literature is moving in the same direction. Work on microstructure and breakage is providing a more detailed understanding of how mineral texture affects fragmentation, while research into slow-compression breakage is examining the transition between single-particle and confined-particle-bed breakage. The big prize is not simply lower specific energy. It is lower specific energy while producing a more useful particle population. That means asking what happens to the particles after they leave the crusher or mill.

One of the most interesting developments at Comminution ’25 was the growing recognition that the grinding environment can affect downstream mineral processing, including subsequent collector adsorption and flotation behaviour. This is another sign that the old boundaries between unit operations are becoming less useful. The comminution engineer cannot simply specify a P80 and hand the product to the flotation engineer. Particle shape, surface chemistry, mineral exposure, fines generation and fracture characteristics can all influence what happens next. By 2027, we may therefore see more papers evaluating comminution performance using downstream recovery and grade, rather than energy consumption and particle size alone. That would be a welcome development. After all, the purpose of grinding is not to make small particles, it is to make valuable minerals recoverable.

Energy efficiency has been a central theme of comminution research for decades, but the sustainability discussion is becoming broader. Water availability is increasingly important, particularly in major mining regions such as Australia, Chile and Peru. Comminution ’25 included several examples of dry grinding, dry classification and flowsheets designed to reduce water consumption. Dry VRM technology, for example, was presented as offering substantial energy savings relative to traditional mill systems, while dry HPGR-based flowsheets were being combined with classification and beneficiation concepts. This suggests that Comminution ’27 may increasingly evaluate technologies against several simultaneous metrics. In other words, specific energy will remain important, but it will no longer be enough. 

Comminution ’25 also contained a healthy dose of scepticism. Grant Ballantyne's keynote asked how metallurgists can distinguish the “fine wine from the snake oil” when assessing new comminution and classification technologies. A lower energy process may have higher wear; improved liberation may not translate into improved recovery; laboratory results may not survive scale-up. That may be an even more important conversation in 2027.

The industry has no shortage of exciting technologies. High-voltage pulse power, novel compression devices, advanced stirred mills, AI, sensor-based sorting, digital twins, novel liners, new grinding media and radically different circuit configurations all offer intriguing possibilities. So, what might Comminution ’27 look like? 

At Comminution ’25 we saw the beginnings of a move from understanding comminution towards controlling comminution. We saw AI beginning to enter the mainstream, sensors beginning to reveal what happens inside opaque equipment, and alternative technologies challenging the dominance of conventional SAG and ball milling. Two years later, the test will be whether those ideas have survived contact with operating plants.

That is what could make Comminution ’27 particularly interesting. Not simply what is the latest technology? But which of the technologies we were excited about in 2025 have actually delivered? And perhaps, most importantly, what new ideas will have emerged in the meantime that none of us saw coming? One thing seems certain: if Comminution ’25 was about finding new ways to break rock, Comminution ’27 may be increasingly about knowing why, where, when and how much to break it and making the entire mineral-processing circuit respond accordingly.

#Comminution27
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AI, Critical Minerals and the Race to Build Processing Capacity

The extraordinary growth of artificial intelligence is creating a new and largely unexpected source of demand for minerals. As AI data centres proliferate around the world, the challenge is no longer simply about having enough computing power. Behind every new facility lies a vast physical infrastructure of electricity generation, transmission, transformers, cooling systems and equipment, all of which depend on mineral resources.

A recent study highlighted by Rare Earth Exchanges estimates that copper could account for more than 80% of the total mineral mass associated with AI data-centre infrastructure, with grid transmission and distribution responsible for a significant proportion of that demand. Grain-oriented electrical steel, a specialist steel used in transformer cores, is another potential constraint as electricity networks expand. For materials such as gallium, germanium, graphite and rare earths, however, the bigger concern is not necessarily geological scarcity, but the availability of processing capacity and the concentration of supply chains.

This distinction is important. Finding a mineral deposit is only the beginning. Turning that resource into a consistent, specification-grade material requires processing technologies, expertise, infrastructure and investment. In many cases, these downstream capabilities are considerably more concentrated than the resources themselves.

As AI adds another major source of demand, competition for processing capacity could become increasingly intense. This raises fundamental questions for the minerals industry. Can existing resources be processed more efficiently? Can valuable minerals be recovered from lower-grade ores and complex deposits? Can waste streams and end-of-life products become meaningful sources of secondary supply? And can new technologies reduce the energy, water and environmental footprint of mineral processing?

These are precisely the kinds of questions that need to be addressed by the international mineral processing and extractive metallurgy community.

But there is a bigger question surrounding the rapid expansion of AI: where is this technology taking humanity, and are its benefits sufficient to justify its growing physical and environmental demands? Concerns about employment, human creativity, privacy, misinformation, energy consumption and the longer-term role of humans in an increasingly automated world are becoming increasingly prominent.

Whatever the answers, one thing is clear: the AI revolution is not purely digital. Its expansion depends on enormous quantities of metals, minerals, energy and infrastructure. If AI is to deliver genuine benefits to society, the systems supporting it will need to be developed as efficiently and responsibly as possible.

This is where MEI Conferences can play an important role. By bringing together researchers, technology developers, equipment manufacturers, consultants and industrial practitioners, MEI provides a forum where emerging processing challenges can be discussed alongside practical experience from operations around the world.

The critical-minerals challenge is not simply a mining challenge. It is a processing, technology and knowledge-sharing challenge. Breakthroughs in mineral separation, flotation, hydrometallurgy, process mineralogy and recycling could unlock resources that would otherwise remain uneconomic or underutilised.

There is also an important circular-economy dimension. If primary supply cannot expand quickly enough to meet growing demand, greater attention will turn towards recovering critical materials from industrial residues, electronic waste and other secondary resources. Developing economically viable processes for these materials will require the kind of cross-disciplinary collaboration that technical conferences can facilitate.

The current AI expansion is therefore more than another source of mineral demand. It is a powerful reminder that the future of technology depends, in part, on our ability to innovate in mineral processing and that how we meet this demand will form part of the wider debate about the kind of technological future we want.

For MEI Conferences, that presents a clear opportunity: to bring together the scientists, engineers and industry professionals developing the technologies that could turn growing mineral demand into more secure, sustainable supply.

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BME Metallurgy first time sponsors of Hydrometallurgy '27 and Flotation '27

BME Metallurgy is sponsoring MEI’s Flotation ’27 and Hydrometallurgy ’27 conferences for the first time, marking an important step in the company’s growing presence in the international mineral processing community.

The sponsorship is new, but BME Metallurgy and its predecessor business are certainly not new to MEI. Before the business was brought under the BME name, representatives of Protea Mining Chemicals were attending MEI’s flotation conferences in 2009, 2015 and 2023.

What has changed is the position of the business within the BME organisation. Protea Mining Chemicals was brought under the BME brand as part of Omnia’s strategy to create a more integrated mining offering, extending from blasting through to mineral processing. BME Metallurgy now presents itself as much more than a supplier of mining chemicals, offering expertise in flotation, leaching, solvent extraction, ion exchange, metal refining and process optimisation.

That makes the choice of MEI’s Flotation and Hydrometallurgy conferences particularly appropriate. Flotation '27 is directly aligned with BME Metallurgy’s reagent business, while hydrometallurgy is becoming increasingly important as the industry tackles more complex ores and seeks improved routes for recovering critical and battery metals.

There is also a strong sustainability theme. BME has been highlighting its work in green chemistry, chemical circularity, reagent recycling and reducing environmental impacts in mineral processing. Hydrometallurgy, in particular, provides opportunities to develop more selective and potentially more sustainable approaches to metal recovery.

The decision to sponsor both conferences therefore appears to reflect more than a conventional marketing exercise. BME Metallurgy is expanding internationally and seeking to establish itself as a technical partner to the mining industry, rather than simply a chemical supplier. MEI’s highly specialised conferences provide an opportunity to put that expertise directly in front of the metallurgists, researchers, mining companies and technology providers shaping the future of mineral processing.

In this respect, the significance of the sponsorship lies less in BME’s first appearance at an MEI conference, because its predecessor has been attending for many years,  and more in the decision to now put the BME Metallurgy name prominently behind two of the industry’s leading technical forums.

It suggests that BME sees Flotation '27 and Hydrometallurgy '27 not simply as markets for its products, but as important parts of the business it wants to build for the future.

Note that the conference has been rescheduled to September
rather than November as initially announced

#Hydrometallurgy27
#Flotation27
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September Mining Sundowner and SW England's strategic minerals hub

A fine autumn evening yesterday for the September Cornish Mining Sundowner at Falmouth's Chain Locker. Although a modest turnout, it was an interesting one, with two former CSM Associates secretaries, past and current presidents of the Camborne School of Mines Student Union, one "fresher" and Sam Wood, all the way from Buxton in Derbyshire to celebrate 50 years to the day that he began his student years at CSM. I was one of his lecturers and as far as we know only one of two still alive! 

It has been an exciting few months for critical minerals in South-West England, and particularly for the old mining districts of Cornwall and Devon. The most dramatic development came last month, when the UK National Wealth Fund announced an investment of up to £71 million in Tungsten West to help restart the Hemerdon tungsten and tin mine near Plymouth in Devon. The package includes £36 million of equity and up to £35 million of debt, while the Government will have the right to secure up to half of the mine’s annual tungsten production. With tungsten now firmly recognised as a strategic mineral, and China dominating global supply, the decision is a significant indication of how seriously the UK Government is now taking domestic mineral resources.

This is particularly interesting when viewed alongside developments further west in Cornwall. At South Crofty, near Camborne, Cornish Metals continues to advance its plans for a return to tin production, following further National Wealth Fund support announced in May. Lithium developments are also progressing, with Cornish Lithium's projects seeking to demonstrate that lithium can be extracted from the region's granites and geothermal waters using innovative, lower-impact processes. The Government's new Critical Minerals Strategy specifically highlights Cornwall's work on Direct Lithium Extraction and the potential to combine lithium recovery with geothermal energy.

The really significant change is therefore not simply that individual projects are progressing, but that Cornwall and Devon are increasingly being viewed as a strategic UK mineral province. Tin, tungsten and lithium all feature prominently in the Government's critical minerals thinking, while the region is also developing expertise in processing, recycling, geothermal energy and other parts of the supply chain. The South-West has always had the geology; what has been lacking in recent decades has been the investment and confidence to turn that geological potential into operating mines and supply chains. The events of 2026 suggest that this may finally be changing.

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Mantos Blancos NovaCell Pilot Study Receives Prestigious CEEC Medal

We are pleased to announce that a paper presented at MEI’s Flotation ’25 has received the highest recognition from the Coalition for Minerals Efficiency (CEEC), with the 2025 CEEC Technical Research Medal recognising an outstanding contribution to more efficient and sustainable minerals processing.

The award-winning paper, NovaCell Pilot Performance at Mantos Blancos: Advancing Toward Full-Scale Implementation, was authored by P. Amelunxen, B. Akerstrom and E. Jaques of Capstone Copper, Canada; A. Flores and L. Parraguez of Capstone Copper, Chile; M. Saavedra of Jord, Chile; and L. Cooper and S. Morgan of Jord, Australia. The paper was presented at Flotation ’25 by Alfonso Flores Carrillo of Capstone Copper, Chile.

The NovaCell is the latest flotation technology developed by Professor Graeme Jameson (seen left with Alfonso at Flotation '25). This innovative flotation device incorporates distinct recovery zones designed to improve the recovery of both coarse and fine particles. Australian company Jord holds the exclusive global commercialisation rights for the technology.

In late 2024, a NovaCell pilot plant was installed at Capstone Copper’s Mantos Blancos operation in Chile to process rougher tailings and validate encouraging laboratory results obtained in 2023. The pilot consistently exceeded expectations for both upgrade ratio and mass pull, providing strong evidence to support the advancement towards full-scale design and installation of a Jord NovaCell at the operation.

The CEEC Technical Research Medal is an important recognition of the collaborative work undertaken by the Capstone Copper and Jord teams and highlights the potential of NovaCell to contribute to more efficient and sustainable minerals processing. Congratulations to all the authors and everyone involved in the successful Mantos Blancos pilot programme.

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