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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Biology’s growing role in the critical minerals revolution

For decades, advances in mineral processing have largely come through improvements in chemistry, equipment and process engineering. Now, a new frontier is emerging, one that borrows its inspiration from nature itself. If recent developments are any indication, biotechnology could become one of the most important innovations in the recovery of critical minerals.

The latest evidence comes from Battelle, whose researchers have announced a breakthrough in the selective separation of rare earth elements using engineered proteins. Their work demonstrates that specially designed calcium-binding proteins can distinguish between chemically similar rare earths, achieving impressive levels of purity and recovery in a single-stage, water-based process without the need for conventional chelating agents. It is an exciting development because separation, rather than extraction, remains one of the greatest technical and economic challenges in the rare earth supply chain.

The announcement also provides a timely backdrop to a keynote presentation at MEI’s Critical Minerals ’26, where Chun-Xia Zhao and colleagues from Adelaide University and the ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals will present a sustainable biotechnology platform for mineral recovery that shares the same underlying vision: using peptides and proteins as highly selective molecular tools for separating valuable minerals and metals.

The principle is remarkably elegant. Instead of relying on increasingly intensive chemical processes to force materials apart, these bioinspired molecules are engineered to recognise specific minerals and metal ions with exceptional affinity. Like a lock designed for a particular key, they selectively bind target materials, including rare earth elements and precious metals, while leaving others behind. By incorporating these peptides into recyclable protein systems, the Adelaide team has created a platform capable of repeated separation cycles without losing performance, while recombinant production offers a scalable and potentially cost-effective route to manufacturing the biomolecules themselves.

Perhaps most significant is the breadth of applications. The technology is not confined to primary mining operations; it has equal relevance to the rapidly expanding field of urban mining. End-of-life photovoltaic panels, permanent magnets and batteries represent increasingly valuable secondary resources, but their complex composition makes efficient recovery difficult. Highly selective biological separation offers the prospect of recovering critical materials from these products using water-based processes that avoid many of the harsh solvents associated with conventional techniques.

It would be premature to suggest that proteins are about to replace solvent extraction plants or flotation circuits. Laboratory success must still be translated into robust, high-throughput industrial processes capable of handling the complexity and variability of real ores and recycled feedstocks. Questions of stability, regeneration, process integration and economics will ultimately determine commercial success.

What is becoming increasingly clear, however, is that biology is moving from the margins of mineral processing research into the mainstream. Independent advances from organisations such as Battelle and Adelaide University suggest a broader shift in thinking: the future of critical minerals may depend not only on discovering new deposits, but on designing molecules capable of recognising the elements we need with extraordinary precision.

For an industry challenged to produce more critical minerals while reducing its environmental footprint, that represents a genuinely transformative opportunity and one of the most fascinating themes to watch at Critical Minerals ’26.

#CriticalMinerals26
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Memories of International Mineral Processing Congress 2006, Istanbul

In just over five weeks time the 32nd International Mineral Processing Congress will be held in Cape Town. The 23rd IMPC was held in Istanbul, Türkiye 20 years ago this month, from 3-8 September 2006. The location was particularly appropriate because Türkiye has a substantial and diverse mineral processing industry, including chromite, copper, lead-zinc, gold, borates, coal and iron. 

Bolstered by a huge Turkish contingent, the IMPC attracted over 900 delegates, then a record number (there were 751 at the last IMPC in USA). The conference included a strong body of research from Turkish universities and mining researchers, alongside international contributions and there were 453 presentations from 46 countries.

Three very memorable social events were held at the magnificent Dolmabahce and Beylerbeyi Palaces, the former being in the European sector of Istanbul, the latter across the Bosporus in Asia, and the farewell dinner was held at the end of the penultimate day of the conference, a magnificent affair rivalling the memorable ‘African Night’ at the previous Cape Town IMPC. In the splendid open air setting of Buyuk Klup, on the Asian side of the Bosporus, we were entertained, over an excellent 4-course meal, to live Turkish music, folk-dancing, and belly-dancing. There was a formal aspect to the evening as well, with final speeches from the organisers, and the lifetime achievement award to Prof. Heinrich Schubert. of the TU Bergakademie Freiberg, Germany.

Jon and I represented MEI, as a media partner, and some of our photos are shown below. There are many familiar faces, some sadly no longer with us, including the conference chairman, Prof. Güven Önal.

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From the rare earth supply challenge to processing solutions: Minerals Engineering and Critical Minerals ’26

A recent review in Minerals Engineering provides a timely assessment of one of the biggest challenges facing the critical minerals sector: how can countries develop secure rare earth elements (REE) supply chains in a world where production and processing remain heavily concentrated in China?

The review examines US domestic REE resources and projects, processing methods, emerging production capacity, non-traditional feedstocks and recycling. It also highlights the need for further R&D and, crucially, for the development of domestic expertise in REE separation and refining.

These are not simply US issues. They are at the heart of the global critical minerals challenge and they provide a timely introduction to the technical programme of Critical Minerals ’26, taking place in Cape Town in November.

As media partner to the conference, Minerals Engineering is particularly well placed to highlight the close relationship between the research published in its pages and the work that will be presented at the conference. The Minerals Engineering review makes an important point: identifying REE resources is only the beginning. The real challenge is developing economic and technically effective flowsheets to concentrate, extract, separate and refine the individual rare earth elements. Critical Minerals ’26 contains a whole session devoted to this challenge.

The programme begins with REE preconcentration and gangue rejection from monazite ore, followed by research into the beneficiation of yttrium and neodymium from an urban deposit. Later in the day, delegates will hear about reagent schemes for REE flotation and the optimisation of flotation from phosphogypsum.

These papers demonstrate the diversity of potential REE feedstocks. Traditional mined ores are being joined by industrial residues, urban deposits and waste materials, precisely the kind of non-traditional resources highlighted in the Minerals Engineering review.

And the programme goes further. Research from South Africa will examine REE extraction from coal fly ash and coal-derived ashes, while another paper investigates the influence of pH-redox conditions on recovering REEs and iron from discard-coal leach solutions.

The message is clear: future REE supply will not necessarily come from conventional mines alone. The review also highlights recycling as an important part of the emerging REE supply landscape. This is another area where the Critical Minerals ’26 programme provides a strong practical counterpart. On the second afternoon, delegates will hear about precipitation of REEs in materials recycling, recovery of REEs from spent computer hard disks using phosphoric acid and deep eutectic solvent leaching, and a life-cycle assessment of mixed REE oxide recovery from end-of-life NdFeB magnets.

These are particularly significant developments because NdFeB magnets contain some of the REEs that are strategically important to modern technologies. Recovering them from end-of-life products could provide a secondary source of supply while reducing dependence on primary mining. The conference therefore moves beyond the question of where can we find more REEs to the more fundamental question of how can we recover them efficiently from everything from ores to industrial wastes and discarded technologies?

Perhaps the most important connection with the Minerals Engineering review is the emphasis on processing expertise. The review points out that many countries have limited REE production capacity and relatively little expertise in REE processing. Developing alternative supply chains therefore requires more than investment in mines. It requires scientists, engineers, metallurgists and process developers capable of designing and operating the separation technologies needed to turn resources into saleable products.

The Critical Minerals ’26 programme reflects this need. Across its 39 presentations, researchers from universities, research organisations and industry will examine beneficiation, flotation, leaching, solvent extraction, ion exchange, precipitation, hydrometallurgy, recycling and process development across a wide range of critical minerals.

And REEs run like a thread through the programme. From monazite beneficiation and REE flotation from phosphogypsum, through coal-derived resources, acid mine drainage, recycling processes, hard-disk magnets and NdFeB magnet recycling, the papers demonstrate just how broad the search for future REE supply has become. The journal review sets out the strategic context: supply-chain concentration, the drive to establish alternative production, the development of domestic separation capacity and the need for R&D.

The conference programme shows that this research is already happening. It shows researchers tackling the difficult mineral processing questions that will determine whether new REE resources, conventional and unconventional, can actually contribute to secure supply.

And that is ultimately the purpose of Critical Minerals ’26: to look beyond the identification of critical mineral resources and focus on the processing and recycling technologies required to turn those resources into resilient supply chains. The conference explicitly covers processing from primary and secondary sources and recycling, including some of the most challenging materials associated with the circular economy. Critical Minerals ’26 offers an opportunity to see many of these emerging technologies first-hand and to meet the researchers and companies working to build the next generation of critical mineral supply chains.

The REE challenge identified in the pages of Minerals Engineering will be very much alive in Cape Town this November.

#CriticalMinerals26
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Recovering silver from solar panels using flotation

Solar panels are one of the defining technologies of the energy transition. But as the first generations of large-scale photovoltaic installations reach the end of their useful lives, a new challenge is emerging: what do we do with millions of tonnes of spent panels?

Australia is particularly exposed to this question. Around one in three Australian households has rooftop solar, and the country is expected to generate around one million tonnes of solar panel waste by 2035. Although panels contain large quantities of glass and aluminium, they also contain smaller quantities of higher-value materials, including copper, silicon and silver.

Silver is used because it combines exceptionally high electrical conductivity allowing tiny quantities of a very valuable metal to be distributed across a huge number of microscopic conductive pathways.

Silver represents only a tiny fraction of the mass of a photovoltaic module. The Queensland Government's recent solar-panel recovery pilot, for example, estimated silver at just 0.003% of panel mass. Yet across millions of panels, even these small quantities add up. The Silver Institute reported photovoltaic demand of 193.5 million ounces of silver in 2023, highlighting just how substantial the solar industry's consumption of the metal has become.

However the silver is finely distributed, embedded within the metallisation of the cell and bonded into the surrounding material. Recovering it selectively is therefore a separation problem and that is precisely where mineral processing enters the picture. Recent research from the University of Newcastle's Centre for Critical Minerals and Urban Mining, together with the ARC Centre of Excellence, published in the July issue of Minerals Engineering, has demonstrated that froth flotation could provide a new route for recovering silver from end-of-life photovoltaic cells.

Traditional research into silver recovery from end-of-life photovoltaic modules has focused heavily on hydrometallurgical approaches, particularly acid leaching. Leaching can be effective, but treating the entire feed chemically creates its own challenges. Large quantities of reagent may be required, and much of that reagent is effectively being used to process material that contains little or no silver.

The University of Newcastle work applies froth flotation as an upstream selective recovery step for metallic silver from end-of-life photovoltaic cells. In laboratory-scale experiments, delaminated cells from waste solar panels were processed using conventional flotation reagents and the results were striking. In a rougher flotation test using tap water, the researchers achieved approximately 98% silver recovery, with a 32-fold upgrade. The flotation response was also rapid, with around 80% recovery achieved within the first minute and around 90% after approximately three minutes. Perhaps most importantly from a flowsheet perspective, flotation reduced the material requiring subsequent leaching to just 2.8% of the original feed.

The researchers' cleaner-stage experiment illustrates the potential. A rougher-cleaner configuration increased the upgrade to approximately 63, at around 87% silver recovery, producing a concentrate containing approximately 47 wt% Ag.

Of course, these are only batch laboratory results rather than evidence of a commercial-scale flowsheet. In a recent preprint they have reported impressive continuous steady state results processing the silicon wafer sourced from almost half a tonne of solar panels, bordering on 100% silver recovery with 83-fold upgrade to around 50 wt% Ag.

There is still more work to be done around feed preparation, liberation, circuit configuration, reagent optimisation, scale-up and economics. But the conceptual leap is significant. This is exactly the sort of development that demonstrates why the scope of flotation continues to expand.

MEI's Flotation '27 will bring together researchers and practitioners to discuss everything from fundamental reagent chemistry and bubble-particle interactions to flotation kinetics, hydrodynamics, scale-up, circuit design, modelling, control and environmental considerations. The solar-panel work touches on almost all of these themes.

These are not simply questions about recovering silver. They are questions about how the mineral-processing toolbox can be adapted to the emerging world of secondary resources.

The ARC Centre of Excellence is a significant University of Newcastle credential. The fact that Newcastle was awarded $35m to lead a national centre, alongside universities such as Queensland, Melbourne, Monash, New South Wales and Curtin, is strong evidence that the research group is regarded as a leading Australian centre in this area and the Newcastle group has always had a strong involvement with MEI's flotation conferences. Their involvement in the solar-recycling research is an interesting illustration of how expertise developed around conventional mineral processing problems can be transferred to entirely new resources.

The energy transition is creating a paradox. Technologies designed to reduce environmental impact require enormous quantities of materials. Those materials have to be mined, processed, manufactured and eventually recovered. The challenge is therefore not simply to build more solar panels, batteries, wind turbines and electric vehicles. It is to develop systems capable of recovering the materials contained within them when they reach the end of their useful lives. That is where mineral processing has a vitally important role.

Since publication of this post Flotation '27 has been re-scheduled to September 20-23. 2027

#Flotation27

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August summary: the solar eclipse and a remarkable Cornish museum

August opened up with two more heatwaves, leading to drought conditions over most of England, including Cornwall. 

A parched Falmouth

The beaches have been packed, no more so than on the 12th of the month. August 7th-16th was  Falmouth Week, which  grew out of a sailing regatta whose roots go back to 1837. Today it's a Cornish mixture of sailing, harbour activity, live music, family events, parades and spectacular displays, bringing the town alive.

The 12th was particularly special as the Wednesday is usually dominated by an evening display by the RAF's Red Arrows, but this year there was another, more low-key evening air display and by an extraordinary coincidence the air display coincided with a 95% partial solar eclipse, the most significant solar eclipse visible from Cornwall since the total eclipse of 1999.

The aerial performances took place in the evening, from around 6pm, with the eclipsing Sun creating the backdrop as an eerie twilight descended.

Falmouth's Gyllyngvase beach at 6pm

95% totality just after 7pm

Although this was a rare occurrence I have to admit to being slightly underwhelmed. Maybe I still have in my mind exactly 27 years previously when Falmouth was on the line of totality. Although the weather was awful and the eclipsed sun was not visible I will always remember the slightly frightening sight of the black shadow racing across Falmouth Bay towards us and pitching us into total darkness as it passed.

August 11th 1999: 11am and a few minutes later

On the day after the eclipse many homes were destroyed and wildfires raged in parts of Britain as one of the highest temperatures of the year was recorded.

This summer is the hottest on record in the UK and much of Europe is on fire. The overwhelming consensus of the global scientific community is that human activity is the primary driver of current climate change (see posting of 24 August), so is 2026 the coolest year we will experience? It is an uncomfortable question, but perhaps one worth asking. The World Meteorological Organisation estimates an 86% chance that at least one year between 2026 and 2030 will be warmer than the current record year, 2024. It also puts the chance of at least one year temporarily exceeding 1.5°C above the pre-industrial average during that period at 91%. These are probabilities, not predictions that every year will be hotter than the last, since natural variations such as El Niño and La Niña will continue to cause fluctuations. But the underlying trend is clear: the baseline on which those fluctuations occur is getting warmer.

There is also a darker reminder of what a warming world can mean beyond heatwaves and wildfires. Last week, catastrophic flash floods struck Nepal after a section of glacier collapsed in the Himalayas, sending an avalanche of ice, rock and water downstream. Hundreds of people have died and thousands remain missing, with homes, roads, bridges and other infrastructure destroyed. Scientists caution that it is too early to attribute this particular event directly to climate change, but the disaster occurred in a region experiencing rapid warming and accelerating glacier loss. As glaciers retreat and high-mountain environments become increasingly unstable, the risks of landslides, avalanches and sudden floods are growing.

The Nepal disaster is a reminder that climate change is not simply a story of temperatures rising year after year. It is about a changing climate system, in which familiar patterns and natural hazards can become more dangerous. Heatwaves, wildfires, extreme rainfall, floods and the destabilisation of glaciers may look like separate events, but they are all part of a world in which the environmental baseline is shifting.

On a lighter note, last Wednesday Barbara and I celebrated our 59th wedding anniversary by visiting a remarkable museum in St. Ive (not to be confused with St. Ives), near Liskeard, 55 miles from Falmouth. The Story of Emily steps into the life and legacy of Emily Hobhouse, the famous humanitarian who was born in St. Ive, and lived from 1860 to 1926. She became internationally known for speaking out against the treatment of Boer women and children during the Second Boer War.

The British Army used a "scorched earth" policy, destroying farms and moving Boer civilians into concentration camps. Emily travelled to South Africa in 1900 to see the situation for herself. In January 1901 she visited the Bloemfontein camp, where around 2,000 women and children were being held. She was horrified by what she found. Women and children were living in terrible conditions, with inadequate food, sanitation and shelter. She documented what she saw and brought the situation to the attention of the British public and politicians. Branded an hysterical woman and traitor by many, she refused to be silenced, saving thousands of Boer women and children, leading social reforms, and single-handedly challenging an empire at war.

I remember visiting Bloemfontein in 1982. It was the capital of the old Orange Free State, one of the two Boer republics that fought Britain. The concentration camp there became one of the most important symbols of the suffering of Boer civilians and the memory was still very much alive, with some turning away as I asked for directions in English. 

Bloemfontein has the Anglo-Boer War Museum and the National Women's Memorial (left), which commemorates the women and children who died in the camps. The museum specifically tells the story of the concentration camps and the suffering of civilians, and although speaking English can cause some resentment in this predominantly Afrikaans city, ironically Emily became enormously respected among Afrikaners because she had stood up for Boer women and children and the Bloemfontein War Museum presents her positively, describing how her visit exposed the conditions in the camps and helped bring about improvements. 

She was invited to unveil the Women's Memorial in 1913, but she was too ill to attend. The wife of President Steyn unveiled it on her behalf, reading her prepared speech at the ceremony. 

Emily died in 1926. Her funeral in London was remarkably small and received little attention. A few months later, however, South Africa gave her a very different farewell.

Her ashes were sent to South Africa, where Isabella "Tibbie" Steyn, the widow of former Orange Free State president Martinus Steyn and a close friend of Hobhouse, helped organise a state funeral in Bloemfontein, the first state funeral for a woman in South Africa. It took place on 27 October 1926 at the National Women's Monument attended by more than 20,000 people. Shops and businesses closed and flags were flown at half-mast and Emily's ashes were placed at the monument.

I'm sure that South African visitors to Cornwall, and anyone interested in South African history, would find the Story of Emily of great interest. The museum is deliberately divided into two very different experiences:

• The Victorian Rectory shows Emily's childhood and early life in rural Cornwall, with restored rooms and gardens recreating the world in which she grew up.
• The War Rooms provide a modern, dark, immersive exhibition about her experiences in South Africa and the concentration camps. It uses original objects, photography, film, animation, sound and virtual reality to put visitors into the historical setting.

The contrast is intentional: the peaceful Cornish home represents Emily's early life, while the stark War Rooms represent the traumatic world she encountered later. One particularly striking feature is that the War Rooms are kept around 26°C, helping recreate the heat of South Africa. The exhibition takes visitors through different environments and uses sound, mirrors and visual effects to convey the scale and human impact of the camps.

Inside the rectory, Emily's Cornish family home

Visiting a "virtual" Boer farmhouse stoep

A devastated farmhouse during Kitchener's scorched earth policy

As well as being overshadowed by the ongoing wars in Iran and Ukraine, August will also be remembered for the loss of two iconic singer-songwriters, Bonnie Tyler and Dolly Parton, whose distinctive voices, unforgettable songs and remarkable careers left an enduring mark on popular music. Their deaths brought an end to two extraordinary chapters in music history on both sides of the Atlantic.

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Is replacing copper with aluminium the most effective way to deal with the looming global copper shortages?

A series of recent studies by reputable organisations have all forecast significant global shortages of copper starting in the mid 2030s.

In a keynote lecture at Critical Minerals '26, Martin Lynch, of the University of Queensland, will argue that substitution is the likely remedy.

Martin will highlight three main points:

• Substitutes (including PEX piping, fibre optic cables, and aluminium tubes) supplied 40% of the global demand for copper over the past 50 years, during which there were two periods of shortage.
• Of the copper consumed globally in 2023, about 70% could have been replaced by substitutes (including aluminium wiring, cables and tubes) without significant negative impacts.
• The main barrier to using substitutes is copper’s reputation for quality, and the reluctance of manufacturers and consumers to trust substitute products (including in building wire, aircon HX and renewables cabling) even though they are proven to work just as well as copper.

According to the author, history has shown that the barriers to substitution tend to crumble quite quickly when shortages appear.

Martin Lynch is the son of the late Prof. Alban Lynch, the first Director of Australia's JKMRC. He graduated in 1982 as a BE (Chem) from the University of Queensland (UQ) and worked in a series of mining companies including Rio Tinto and Iluka Resources.  During that time he wrote Mining in World History, a book which traces the history of global mining from 1500 to the 1970s (posting of 13th July 2026).  

He changed career path in 2009, becoming the owner and manager of a renewables energy business.  This was sold in 2024, following which he began a PhD at UQ focusing on the use of substitutes for copper with the aim of managing forecast global copper shortages.

#CriticalMinerals26
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Is CO₂ Still the Most Maligned Gas in History? — Eight Years On

In the middle of August homes were destroyed as wildfires brought devastation to parts of Britain. The apocalyptic vision of the world on fire, with wildfires raging across Europe and the UK, prompted me to look again at a post I wrote eight years ago, Is CO₂ the Most Maligned Gas in History?. I wrote it in December 2018 when I was sceptical of the evidence attributing most recent climate change to human activity. Eight years later, I think some of the questions I raised remain worth asking, but the scientific answers have become considerably clearer.

The post is still relevant as a historical account of the debate, and some of its points remain valid. CO₂ is essential to life, it is quite different from conventional air pollutants, and mining will be essential to any large-scale transition away from fossil fuels. But its central scientific position, that climate change was probably mainly natural and that the contribution from human activity was uncertain, is no longer supported by the evidence.

In the 2018 article I wrote: “An increase in 40% [of CO₂] seems a lot, but in absolute terms this is an increase in concentration from just under 0.03% to the present level of just over 0.04%. Can this small increase have such a profound effect?” 

The science can now provide a much better answer to that question.

We can also now be much more precise about where the additional CO₂ is coming from. Scientists can distinguish fossil-fuel carbon from naturally circulating carbon by examining the isotopic “fingerprint” of atmospheric CO₂. Fossil fuels contain virtually no radioactive carbon-14, because it has decayed away over the millions of years that they have been underground. They are also relatively depleted in carbon-13. By measuring these isotopes in atmospheric CO₂, scientists can identify the contribution from fossil fuels and distinguish it from carbon being exchanged naturally between the atmosphere, oceans and living organisms.

This provides an important independent line of evidence. We are not simply assuming that the additional CO₂ is coming from burning coal, oil and gas because fossil-fuel use has increased at the same time as atmospheric CO₂. The chemical and isotopic fingerprints show that the extra carbon has the characteristics expected of ancient plant material,  precisely what we would expect from fossil fuels. The National Oceanic and Atmospheric Administration notes that these measurements can be used to determine what proportion of CO₂ in an atmospheric sample is derived from fossil fuels.

The important thing is not simply the percentage of the atmosphere occupied by CO₂, but the physical properties of the molecule and its effect on the Earth's radiative balance. CO₂ absorbs infrared radiation at specific wavelengths. Increasing its concentration makes it more difficult for the Earth to radiate energy back into space. The climate system then warms until outgoing radiation once again balances incoming energy. CO₂ does not have to make up a large proportion of the atmosphere to have a significant climatic effect.

Furthermore, we are no longer relying simply on correlations between CO₂ concentrations and temperature. The radiative effect of increasing greenhouse gases can be observed directly. NASA explains that its climate instruments measure how greenhouse gases affect the movement of infrared radiation through the atmosphere, and a 2024 NASA and Jet Propulsion Laboratory study directly measured how increasing atmospheric CO₂ reduces the Earth's ability to emit infrared radiation into space.

Looking back at my 2018 post, I would therefore no longer argue that the human contribution to recent warming is fundamentally uncertain. The evidence is now much stronger that the current rise in atmospheric CO₂ is overwhelmingly the result of human activity, principally the burning of fossil fuels, and that this increase is the dominant cause of the warming observed since the pre-industrial period.

But that does not make CO₂ a “villain” in the conventional sense. It remains an essential gas for life, occurs naturally, and has played an important role in regulating Earth's climate throughout geological history. Nor does recognising the importance of CO₂ mean that all environmental problems can be reduced to carbon dioxide. Conventional air pollutants such as particulate matter, sulphur dioxide and nitrogen oxides remain important threats to human health.

What has perhaps become even more relevant since I wrote the original article is the other side of the argument. If we accept the need to reduce greenhouse-gas emissions, then mining, a major emitter of CO₂, is not the enemy of the green revolution,  it is one of its essential foundations. Wind turbines, solar panels, electricity networks, batteries and electric vehicles all require large quantities of metals and minerals. The energy transition will therefore require more mining, not less (see posting of 10 April 2023).

The scale of the challenge is illustrated by the graphic below. In 2023, the world was still consuming enormous quantities of coal, oil and natural gas, with China and the United States among the largest consumers. Replacing an energy system of this scale is clearly going to be a very substantial undertaking.

Source: elements.visualcapitalist.com

This brings us back to the paradox at the heart of this article. If we accept the need to reduce greenhouse-gas emissions, mining is not the enemy of the green revolution, it is one of its essential foundations. The challenge is not simply to “stop mining”, but to produce the minerals needed for decarbonisation while reducing the environmental footprint and carbon intensity of their extraction and processing.

In that sense, my 2018 article is worth revisiting not because its scepticism about human-caused climate change has been vindicated, but because its underlying question has become even more important: how do we reconcile our environmental ambitions with the enormous material requirements of a modern, low-carbon society?

This is the paradox we should be discussing now. The route to a lower-carbon world runs, at least for the foreseeable future, through a mining industry that itself has to become substantially lower carbon.

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August Cornish Mining Sundowner, and Cornwall's next Industrial Chapter?

A cool evening, a rare occurrence this long hot summer. It was a pleasant 17C last night in Falmouth for the Cornish Mining Sundowner at the Chain Locker, with a modest attendance of around a dozen.

The Chain Locker sits by Falmouth's inner harbour, the more sheltered, upstream section around the town quays, while the wider Falmouth Harbour extends out towards Carrick Roads (the Fal estuary) and the sea, so there was something rather appropriate about discussing Cornwall’s industrial future from the Chain Locker last night.

The Inner Harbour and the Chain Locker

Look across Falmouth Harbour and you see centuries of working history, ships, quays, docks and warehouses. But the harbour may also have a role in Cornwall’s next industrial chapter.

A proposed £150 million redevelopment of Falmouth Docks aims to modernise the ageing infrastructure, increase cargo capacity and support the emerging floating offshore wind industry in the Celtic Sea. Importantly for Cornwall’s renewed interest in critical minerals, the plans could also create new import and export facilities supporting Cornish lithium and battery manufacturing.

Cornwall once exported copper and tin through its ports to markets around the world. Could Falmouth once again become part of a supply chain built around Cornwall’s natural resources, this time alongside renewable energy and modern marine engineering?

There is, however, another side to the story. The redevelopment has attracted opposition from oyster fishermen and environmental campaigners, particularly over proposed dredging and its potential impact on the Fal estuary and its habitats. So the question isn't simply whether Cornwall can bring industry back, it is what sort of industry we want, and how we balance economic opportunity with the environment and communities that make Cornwall special.

Join us at the Chain Locker for the next sundowner, which will be on Thursday September 17th, from 5.30pm.

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Eriez is the latest sponsor of Flotation '27

We are pleased to welcome Eriez as the latest sponsor of next year’s Flotation ’27. In fact, we are delighted to welcome them back, as Eriez has sponsored every MEI flotation conference since Flotation ’19, held just before the pandemic.

The Eriez booth at Flotation '19, the company's first year as a sponsor

The Eriez Flotation Division (EFD) delivers advanced flotation solutions designed to boost recovery while reducing operating costs. With more than 1,000 flotation systems designed, supplied and commissioned worldwide, Eriez offers a range of technologies aimed at achieving step-change improvements in mineral processing.

The strategic theme behind EFD is essentially more mineral recovery with less energy, water, equipment and grinding, using its broad range of flotation technologies. These include HydroFloat for coarse-particle recovery, CavTube Column Flotation, StackCell mechanical flotation and advanced sparging systems.

President and CEO Jaisen Kohmuench and Mining and Minerals Head Todd Burchett discussed step-change technologies at the SME Annual Meeting in Salt Lake City in February, highlighting integrated flowsheets incorporating HydroFloat Coarse Particle Flotation and StackCell systems.

Through technologies such as the HydroFloat separator, Eriez continues to advance coarse-particle recovery, with the potential to significantly reduce grinding energy, conserve water and enable safer tailings management. This work is often carried out in partnership with other equipment providers, including Comminution '27 sponsor Weir Minerals. In 2022 Weir Minerals announced a cooperative agreement with Eriez to design and develop coarse-particle flotation systems, allowing the two companies to better integrate Eriez flotation equipment with Weir Minerals’ expertise in slurry classification and conveying.

The commissioning of a HydroFloat installation at BHP’s Carrapateena copper mine in Australia is one of the more significant recent commercial references for Eriez’s HydroFloat technology.

Eriez is also addressing both ends of the particle-size challenge in mineral flotation: HydroFloat for coarse particles and CavTube for ultrafine particles. The current growth story for CavTube appears to be strongly linked to fine-particle and slimes recovery, as well as applications in phosphate and potash, with potential for other challenging ultrafine applications.

EFD is also participating in the University of Queensland’s Collaborative Consortium for Coarse Particle Processing Research, alongside major mining companies including BHP, Rio Tinto, Vale and Codelco. The second five-year phase of the programme, running from 2025 to 2030, is investigating coarse-particle and fluidised-bed flotation as potential routes to reducing grinding energy and improving mineral-processing efficiency.

There is clearly much happening within EFD, and with Flotation ’27 still 15 months away, we can look forward to hearing much more from Eriez next year, both in the conference room and at the Eriez exhibition booth.

Since publication of this post Flotation '27 has been re-scheduled to September 20-23. 2027

#Flotation27
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$3 Billion for Mining: The West’s Critical Minerals Wake-Up Call

On August 7th US President Donald Trump announced a mining/critical minerals  investment package of roughly $3 billion. The announcement came during a mining industry round-table at the State Department. Trump said the administration was backing a series of projects intended to expand U.S. production of critical minerals.

Trump’s investment in mining and critical minerals is about much more than securing new sources of ore. It is about reducing the West’s dependence on China for processing the minerals it needs.

For decades, China has built a dominant position in the critical minerals supply chain, particularly in processing, separation and refining. This means that even when minerals are mined elsewhere, they may still depend on Chinese processing capacity before they can be turned into materials suitable for advanced manufacturing, energy technologies and defence applications. That dependence has become a strategic vulnerability.

The US investment signals a growing determination to bring critical-mineral processing capacity back to the West and develop more resilient supply chains. Crucially, this requires investment not just in mines, but in the technologies, pilot plants, research programmes and skilled people needed to process increasingly complex resources economically.

The emphasis on universities and research is therefore particularly significant. More than $180 million is being directed towards mining education and workforce development, including support for U.S. mining schools to train the next generation of engineers, geologists, technicians and other specialists needed to expand domestic capacity. This reflects a wider concern about the shortage of skilled workers across the mining sector, at a time when the U.S. is seeking to bring more critical mineral production and processing onshore. Alongside workforce development, other programmes are supporting research into critical mineral processing, recycling and recovery from unconventional resources. This is important because securing supply is not simply a question of finding new deposits: it also depends on developing more efficient ways to extract, separate and recover minerals from existing ores, waste streams and alternative sources, helping to reduce reliance on overseas processing and build more resilient domestic supply chains.

This is directly relevant to MEI’s Critical Minerals ’26. The conference will focus on the technologies needed to process and recycle critical minerals from primary and secondary resources - precisely the capabilities that the West needs to develop if it is to build supply chains that are less dependent on China.

The strategic objective is becoming increasingly clear: the West needs not only its own mines, but its own processing expertise and capacity. The coming years could therefore see a major shift in where critical minerals are processed; from a supply chain heavily centred on China towards more geographically diverse capacity in the US, Europe and other allied nations.

For the minerals processing community, this represents both a major challenge and a major opportunity. The technologies developed today could determine where the critical minerals supply chains of tomorrow are built.

That makes the forthcoming agenda at Critical Minerals ’26 in Cape Town especially timely.

#CriticalMinerals26
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Developments in Heap Leaching as a Technology Choice for Value Extraction from Primary and Secondary Resources

Heap leaching is part of the group of “percolation leaching” processes that selectively remove metal values from an ore into a suitable aqueous leaching agent that seeps through a pile or mass of the ore. It has become well-established technology choice for the treatment of low-grade copper and gold ores and is also practiced for uranium ores and REE recovery from ion adsorption clays. Various other applications (Zn, Ni, PGMs) have been explored but not reached commercial significance as yet. 

Apart from the different chemistries and mineralogies, all these applications operate on very similar principles, which will be laid out in some detail in a keynote from Prof. Jochen Petersen, of the University of Cape Town, at Hydrometallurgy '27.

Selection of heap leaching as process technology is primarily driven by its ability to extract value from low-grade materials, as the need for high capital and operating expenditures, especially for intensive comminution processes to produce a concentrate material for further processing, is avoided. However, the relatively long time required to recover the metal value from larger particles, with overall poorer metal extraction achieved, imposes certain economic penalties which have resulted in heap leaching remaining limited to low-grade ores.

Nonetheless, ever-increasing energy costs and awareness of the associated carbon footprint have recently led to a re-evaluation of the technology for primary ores. At the same time the drive towards resource efficiency and the attainment of circular economies for many metals has also opened significant opportunities for the heap leaching of tailings and waste materials and thus a re-evaluation of the technology. Some examples of these developments will be discussed in Jochen's presentation.

Jochen holds a PhD in Chemical Engineering from the University of Cape Town, where he is now Full Professor after a research career spanning close on 30 years in hydrometallurgy. His research covers leaching and recovery of Cu, Ni, Zn, PGMs, Au and REEs from both primary minerals and secondary resources such as e-waste. His key field of expertise is heap leaching.

Jochen has co-authored over 150 peer-reviewed journal and conference papers and supervised 15 PhDs and 60 MScs to graduation. He was the Editor-in-Chief of the journal Hydrometallurgy 2011-2021 and held a prestigious South African Research Chair 2018-2022.

Jochen at Biohydrometallurgy '10 in Cape Town after
being appointed the new co-editor of Hydrometallurgy.
 He is with Dean Eastbury, his publishing manager at Elsevier

Hydrometallurgy27
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Close encounters with a wild dolphin

August is always a quieter time, particularly in the Northern Hemisphere, where many families are away on holiday. So, today's blog is something a little different from the usual- a look back at a magical couple of months in Cornwall almost half a century ago.

This summer has been unusually hot, and thousands of visitors have taken to the sea. Many have joined wildlife safari trips along the Cornish coast, where the relatively warm waters, influenced by the Gulf Stream, attract an abundance of marine life. Seals are a familiar sight, while basking sharks, the world's second-largest fish, are regular seasonal visitors. Dolphins, however, are always the favourites, delighting passengers and photographers alike.

Dolphins are usually seen in pods, but in early 1978 a solitary male bottlenose dolphin made Falmouth his home. Soon affectionately known by locals as "Beaky", he became something of a celebrity, enchanting residents and visitors alike. For a remarkable period, he chose the harbour and surrounding waters as his territory, creating unforgettable encounters for those lucky enough to meet him. 

The safe waters of the harbour were a favoured location for Camborne School of Mines (CSM) divers to undertake their open water training and it must have been an unforgettable experience for them to share the water with a 350 kg dolphin.

Novice CSM diver and Beaky in Falmouth Harbour

One novice CSM diver, however, probably wished he could forget his first meeting with Beaky.

As Diving Officer for both the CSM and Falmouth branches of the British Sub-Aqua Club, I spent many Sunday mornings supervising students on their first shallow open-water dives. One such dive took place in the rocky gullies off Pendennis Headland, at the mouth of the Fal Estuary.

Beaky and CSM divers off Pendennis Headland

Keeping a close eye on the stream of bubbles from a novice and his experienced Falmouth club buddy, I noticed a familiar dorsal fin approaching. Moments later the fin disappeared beneath the surface, only to be replaced by an explosion of bubbles and the student bursting from the water shouting, "Shark! Shark!"

Still visibly shaken, he later explained what had happened. He had felt a firm nudge in the middle of his back and, turning round, found himself face to face with a large dark shape, a towering dorsal fin and two beady eyes. It was hardly surprising that his imagination ran wild, this was only two years after the release of the movie Jaws!

For the more experienced divers, deeper dives were made in Falmouth Bay from the 24-foot Pisces, skippered by local fisherman Ken Dunstan. Ken had recently been one of the four-man team to make the first deep dive on the wreck of the Rinovia (see post of 22 February 2024).

Beaky soon became familiar with the sound of Pisces and regularly accompanied us on our dives. He would even join us on deep wreck dives for five minutes or so before returning to the surface for air, only to reappear and continue swimming alongside us. 

Word of these remarkable encounters inevitably spread, and in early 1978 we were contacted by the BBC's Blue Peter, then at the height of its popularity as the world's longest-running children's television programme. The production team wanted to see whether Beaky might feature in the programme, so they sent a young researcher to spend a day aboard Pisces in search of Cornwall's famous dolphin.

The search proved remarkably short. Just minutes after leaving Falmouth Harbour, Beaky appeared. We dropped anchor and slipped into the water, where he immediately treated us to one of his wonderful displays, much to the delight of our visitor.

Bottlenose dolphins can reach speeds of up to 25 mph (40 km/h), and one of Beaky's favourite antics was as exhilarating as it was startling. He would charge towards you at full speed before suddenly slamming on the brakes just a few feet away, sending a wall of water crashing over your head. The first time it happened it was impossible not to flinch,until you realised he seemed to take as much pleasure in the surprise as we did.

At one point Ken and his seven-year-old daughter, Nicola, entered the water together. Beaky gently approached them before allowing Nicola to hold his dorsal fin as he slowly carried her in a small circle. It was one of those magical moments that none of us present would ever forget.

Nicola is introduced to Beaky....

Before holding on for a memorable ride

It was February, however, and before long the cold drove us back towards the boat. Beaky, though, clearly hadn't finished playing.

He disappeared beneath the surface and reappeared a minute later with the anchor line draped around his beak. Then, to everyone's amusement, he gently towed Pisces just beyond our reach. After several more minutes of his playful antics, we eventually managed to climb aboard. Our Blue Peter researcher was completely captivated by both Beaky and her first visit to Cornwall, promising that the full production team would soon be returning.

Towing the boat out of reach!

I wish there was a happy end to this story, but that was the last we ever saw of Beaky. Shortly after this episode a series of major winter storms hit the area and Beaky was never seen again. No one knows what became of him. He may simply have moved on, died naturally, or perhaps fallen victim to human activity. There has never been any definitive explanation.

Whatever his fate, those few magical months remain one of my most treasured memories of life beneath the waters of Cornwall. Everyone who encountered Beaky carried away a story to tell, and nearly fifty years later, he is still remembered with great affection by those fortunate enough to have shared his extraordinary world.

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