March Cornish Mining Sundowner: some good and some not so good news from Cornwall

A very average turnout for last night's mining sundowner at Falmouth's Chain Locker, but it was good to welcome two visitors from the Czech Republic, Jan Vrba and Martin Fiser. They represent Asekol, a major environmental organisation based in the Czech Republic that focuses on recycling electronic waste. It is a non-profit "compliance scheme" that represents manufacturers and importers of electrical and electronic equipment, its main job being to help companies meet legal requirements for collecting and recycling old electronics.

Jan and Vrba are in Cornwall to talk to Gravity Mining, one of MEI's Physical Separation '26 sponsors, about Multi-Gravity Separators, and Holman-Wilfley about shaking tables, for the recycling of WEE to recover precious metals. Left to right in the photo are Dave Goldburn, of Holman-Wilfley, Martin, Treve Mildren, of Gravity Mining, and Jan.  Dave Goldburn is also involved with Physical Separation '26 and will be co-chairing the first session at the conference.

There was some disheartening Cornish Mining news a few weeks ago.  British Lithium has been extracting lithium from the decomposed granite at a china clay pit, owned by Imerys, a French multinational company, which, in 2023, acquired an 80% stake in British Lithium. The transaction brought together Imerys’ expertise in mining, R&D and process development capabilities, as well as its lithium mineral resources, with British Lithium’s bespoke technology and state-of-the-art lithium pilot plant, which in 2024 began producing battery-grade lithium carbonate. Sadly Imerys recently announced a strategic decision to place Imerys British Lithium (IBL) into a care and maintenance phase, suspending active development for the foreseeable future. The decision was driven by capital allocation constraints and the need to find a long-term partner to support the project at this time.

Some good news, however, that Geothermal Engineering Ltd (GEL) has commenced electricity generation at its United Downs Deep Geothermal Power Project near Truro, marking the first commercial deep geothermal power production in the United Kingdom.

The plant is designed to deliver approximately 3 MW of continuous, renewable baseload electricity, sufficient to supply around 10,000 homes. Electricity generated at the site is being supplied to the grid under a long-term power purchase agreement with Octopus Energy.

The United Downs facility utilises geothermal water from depths of more than 5 km beneath the surface. In addition to electricity generation, the project is also progressing lithium recovery from geothermal brines, creating a combined renewable energy and critical minerals operation (see also posting of 18 September 2020).

The start of generation represents a significant milestone for GEL and for the development of geothermal energy in Cornwall and the wider UK.

And finally, it is always good to hear of my past CSM students being awarded for their endeavours. Dave Meadows is Chief Technology Officer with Bechtel Mining and Minerals, USA. He graduated from Camborne in 1985 with an honours degree in Mineral Processing Technology. After 12 years in South Africa he moved to the USA with Bechtel, and then had 10 years with Freeport McMoRan and FLSmidth before settling with Bechtel in 2015, I missed the Society for Mining, Metallurgy & Exploration (SME) Annual Meeting in Salt Lake City last month, where Dave was named a Fellow of the SME. Well done Dave!

Dave with Mary Korpi, SME President

The next Cornish Mining Sundowner is at Falmouth's Chain Locker on Thursday April 16th, from 5.30pm.

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Leading microscope manufacturer Zeiss continues its involvement with MEI Process Mineralogy conferences

We are very pleased to welcome Zeiss to Process Mineralogy '26, as this well known company has been a sponsor of all MEI's Process Mineralogy conferences since Process Mineralogy '12, the 2nd in the series. 

Carl Zeiss AG, commonly known as Zeiss, is a German manufacturer of high-precision optical and optoelectronic systems. Founded in 1846 in Jena, Germany, the company is one of the world’s most respected names in optics. The company regularly sponsors the process mineralogy series because their technologies are integral to many topics discussed at the conference, particularly automated and quantitative mineralogical analysis and imaging techniques.

Process Mineralogy '26 is shaping up nicely with two high profile keynote lectures and eight of the 10 booths in the small exhibition already taken.

Zeiss exhibition booth at Process Mineralogy '18

There is a call for abstracts, which should be submitted by May 31st, and a wonderful venue for the conference dinner, at the Kirstenbosch Botanical Gardens. An added bonus is the two-day Critical Minerals '26 which immediately follows Process Mineralogy '26 at the Vineyard Hotel.

Kirstenbosch Botanical Gardens

If you have never been to an MEI Conference in Cape Town, this video, taken at Process Mineralogy '14, will show you what to expect.

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Memories of Comminution '06, Perth, Australia

Comminution '06 was held at the Sheraton Hotel, Perth, 20 years ago this month. It immediately followed Gravity Concentration '06 at the same venue. The event was sponsored by Xstrata Technology, Metso Minerals and the Gold & Minerals Gazette, and Mark Fraser, of the Gold & Minerals Gazette provided a comprehensive report on the conference programme.

Comminution '06 was the 5th in the comminution series, and the most disappointing, with only 48 delegates; there had been 125 attendees at Comminution '04, also in Perth (posting of 25 March 2024).

Due to the low turnout, it was decided to give comminution another chance in a venue closer to home, and Comminution '08 was held in Falmouth, with a record 157 delegates, realistically more than the hotel could handle, so we then moved again for Comminution '10, to Cape Town, where it has remained ever since. It has progressively got bigger and better- Comminution '06 had 48 delegates and 21 presentations, over two and a half days, and last years' Comminution '25 had 237 delegates and 94 presentations over four days, and the signs are that next year's Comminution '27 will be even bigger, with 18 sponsors so far, and only one exhibition booth remaining for rental.

I am sure you will recognise a few faces at Comminution '06, and some will no doubt be seen at next year's event.

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Memories of Gravity Concentration '06, Perth Australia

Gravity Concentration '06 was held at the Sheraton Hotel, Perth, from March 13-14, 2006. It was MEI's 3rd International Gravity Concentration Symposium, and was sponsored by Falcon Concentrators, Gekko Systems, Roche Mining and the Gold & Minerals Gazette, published by Australia's Resource Information Unit.

The 2-day event was attended by 48 delegates and a full report  on the programme was provided by Mark Fraser, of the Gold & Minerals Gazette.

This was our final Gravity Concentration conference, the conference merging with Hydrocyclones, Solid-Liquid Separation and Magnetic & Electrical Separation conferences to produce the first Physical Separation conference three years later. This proved to be a very popular small conference, and the 9th in the series is only six weeks away. You may recognise a few faces below of 20 years ago, who will be at the conference in Cape Town next month:

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New book: The Art and Science of the Flowsheet

In this new book, launched at last month's SME Annual Meeting in Salt lake City, John O. Marsden explores the essential visual language of extractive metallurgy, the flowsheet,and the unique intersection where engineering meets art. From the hand-drawn process diagrams of the 19th century to today’s digital simulations, Marsden traces how these schematic representations have evolved to capture the innovation, precision, and creativity that define mineral processing. 

Richly illustrated with more than 190 historical and modern flowsheets, this volume tells the story of how metallurgists, engineers, and draftsmen have translated complex processes into elegant, functional design. Through examples spanning gold, copper, nickel, lithium, and other key commodities, Marsden reveals how each diagram reflects its era’s technology, challenges, and ingenuity and how flowsheets continue to shape the efficiency and sustainability of modern operations.  

Part history, part technical guide, and part visual tribute, The Art and Science of the Flowsheet invites readers to appreciate the discipline as both a craft and a cornerstone of process design.  With more than 200 full color flowsheets and diagrams, this book is a definitive reference for metallurgists, process engineers, and students - those who still sketch ideas on napkins, seek clarity in complexity, and understand that every good flowsheet tells a story.

John Marsden (left) at the SME Bookstore in Salt Lake City

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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."

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