Recent comments

There have been comments on the following postings since the last update.

Memories of Reagents '04, Falmouth
Back to our roots in the industrial north
10 good reasons to spend some time in Cape Town
In memory of Richard Mozley and his wonderful machines
June summary: zero carbon by 2030?
Mine waste transformation through characterisation- a mission to re-imagine waste management
An appreciation of JC Burrow- pioneering underground mining photographer

We welcome and encourage your comments on blog postings (see also the posting of 2nd April 2019). If you do not have a Google account, the simplest way to add a comment is by selecting 'anonymous' as your profile, but please leave your name and affiliation in the comment. Alternatively, email your comment directly to bwills@min-eng.com.

Interacting with comments enhances your international presence by providing you, and your company or Institute, with valuable exposure.

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Integrated Sensor Based Sorting and HPGR Comminution Circuit for Improved Energy Efficiency

Energy efficiency is a primary focus for the mineral processing flowsheets of the future. In recent years, High Pressure Grinding Rolls (HPGR) have demonstrated significant energy savings as compared to conventional SAG mill circuits and Alex Doll, of Alex G. Doll Consulting Ltd, Ireland, has produced a 22 minute video which discusses the similarities, the strengths and the weaknesses of these two important comminution techniques.

The integration of energy efficient comminution with sensor-based sorting (SBS) has the potential to significantly reduce overall mineral processing energy usage, by rejecting low grade rock ahead of energy intensive comminution, and SBS has featured strongly in recent MEI Conferences, particularly in comminution conferences, and it was good to hear that a paper presented at Comminution '23, a cooperation between Steinert Latinoamericana, Nexa Resources and MinPro Solutions, has received a High Commendation from CEEC, one of our conference industry advocates. The paper proposed an interdisciplinary and holistic approach to better understand the impacts of SBS on a SABC circuit for a polymetallic ore, the results pointing to a 10% increase in grinding capacity, 44% reduction in water usage, 34% reduction in energy consumption and 43% reduction in fine tailings generation. In addition, the metal production and recovery were improved due to a better performance in flotation. 

We can expect much more on SBS at next year's Comminution '25 in Cape Town and in a keynote lecture, Bern Klein, Professor of Mineral Process Engineering at the University of British Columbia, Canada, will present a conceptual SBS with HPGR comminution circuit in tertiary and quaternary stages. The energy consumption will be compared to a conventional SABC circuit for a large copper mine. 

There is a call for abstracts for Comminution '25, which should be submitted by October 31st. If you would like to exhibit please let us know as soon as possible, as due to high demand, and the main exhibition area selling out, we have placed extra 2x1m booths outside the conference room, but only 3 are currently available.

#Comminution25

July Cornish Mining Sundowner: some good and some sad news

The hottest day of the year so far drew a good turn-out for last night's Cornish Mining Sundowner at Falmouth's Chain Locker.

There was some good news and some sad news. At the UK Mining Conference in Falmouth last year Camborne School of Mines (CSM) Director Pat Foster discussed the problems in finding the future mining workforce internationally. There were no undergraduate mining degrees in the UK, as the CSM degree had been 'paused' by the University of Exeter from the 2021-22 academic year, such that the last students graduated in 2023.

The controversial decision to pause effectively brought an end to CSM's proud record of training graduate mining engineers, which has its origins back to 1888. However, good news came from the CSM Alumni Australia Gala Dinner in Perth earlier in the month, when the University of Exeter Vice Chancellor Lisa Roberts gave the keynote speech updating over 180 guests on developments at CSM and how important it is to the University. She delighted everyone by announcing that Camborne School of Mines, University of Exeter, will be resuming its full-time undergraduate degree in Mining Engineering in 2025.

This is great news not only for the global industry but particularly for mining in SW England, with good progress on re-opening the South Crofty tin mine in Camborne and with lithium production at British Lithium and Cornish Lithium. And just across the border in Devon, news that Tungsten West has received its final permit from the Environmental Agency for the mine processing facility, completing the suite of permits needed to process tungsten, tin, and aggregates. 

On a more sombre note. since the last sundowner it has been sad to hear of the death of Bernard Ballard (1954-2024) who has been very much a part of the Cornish mining scene since 1988 when he joined Carnon Consolidated Tin Mines Ltd based at Wheal Jane, where he was engaged in various diversification projects, estate management and other management roles until 1998.

During that 10 years with the company he was also involved with events such as the closure of Wheal Jane mine in 1991 and the closure and sale of South Crofty Plc and the mine in 1998.

Following the closure of South Crofty he was one of five managers at South Crofty Plc who completed a management buyout of the subsidiary businesses and assets of that company and the formation of the Wheal Jane Group. This new company took over the Wheal Jane site where those businesses continued to grow as part of the development of the site as a specialist business cluster with a particular focus on mining, minerals and renewable energy, the Wheal Jane Earth Science Park.

Bernard was Secretary and a Director of the Cornish Chamber of Mines and Minerals for 23 years and became Chairman in 2016. He was also a member of the Cornwall Mining Alliance (CMA) Steering Group. The CMA was launched at the October sundowner in Penryn in 2016.

The CMA Steering Committee in 2016: Bernard Ballard, Kim-Marie Clothier,
Kathy Hicks, Frances Wall, Jean Taylor and Tony Bennett

The next Cornish Mining Sundowner will be at the Chain Locker on Thursday August 15th from 5.30pm.

Looking great for Process Mineralogy '24 and Critical Minerals '24 this November

After a gap of 6 years it will be great to bring MEI's Process Mineralogy conferences back to Cape Town. Due to Covid restrictions Process Mineralogy '22 was held in Spain. Process Mineralogy '24 in November will be the 7th in the series, with a welcome return to the Vineyard Hotel.

And immediately following Process Mineralogy '24 we have our inaugural Critical Minerals '24, also at the Vineyard. Both conferences are sponsored by Capstone Copper, Petrolab, Conundrum, AECI Mining Chemicals and Promet101, ZEISS also sponsoring Process Mineralogy '24 and Steinert Critical Minerals '24.

Our media partners are International Mining and Minerals Engineering, with industry advocate the Critical Minerals Association. CEEC is also an industry advocate for Critical Minerals '24.

We have very strong technical programmes for both conferences, with high profile keynote speakers.

The programme for Process Mineralogy '24 contains three keynote speakers. Geometallurgy is a buzz word these days and Stewart Brand, who is Principal of Global Geometallurgy in the BHP Resource Centre of Excellence, Australia, will look at the future of geometallurgy in the opening keynote.

Quentin Dehaine, a senior researcher at the Geological Survey of Finland, will open the second day with his keynote assessing trends in cobalt mining and processing in relation to mineralogy and on the final day Anita Parbhakar-Fox, of the University of Queensland, Australia, will discuss a mission to reimagine waste management by looking at mine waste transformation through characterisation.

There has been a great response to Critical Minerals '24, which with hindsight might have been better served by three rather than two days, and the very full programme also contains three keynotes.

Markus Reuter, Chief Expert at the SMS Group, Germany, opens the first day discussing the fundamental limits of the supply chain of critical metals and minerals within the circular economy and in the afternoon session on rare earth elements, Damien Krebs, study manager and metallurgist at Primero Group, Australia will review the extractive metallurgy of rare earths. The final day will open with Alan Butcher, Chief Scientist and Technical Director of the Hafren Scientific Group, UK discussing battery minerals, metals and materials as a prelude to a session on battery metals and graphite.

It won't be all about technical presentations though, as with all MEI Conferences there will be plenty of time for socialising in the Vineyard gardens and in the exhibition areas, and informal conference dinners, at Cape Town's Gold Restaurant for Process Mineralogy delegates and the Groot Constantia Wine Estate for Critical Minerals delegates.

We are looking forward to November in Cape Town, and hope to see you there.

The view of Table Mountain from the Vineyard Conference Centre

#ProcessMineralogy24
#CriticalMinerals24

SAIMM Rare Earths Conference 2024

By Amanda Wills

I had the pleasure of attending the SAIMM Rare Earths 2nd International Conference 2024 in Swakopmund, Namibia on June 19-20.

The event began with the Welcome Cocktail & Early Registration on Tuesday 18th June, at the Swakopmund Hotel and Entertainment Centre, where the conference was held.

I spent a pleasant couple of hours chatting with old friends and new whilst enjoying a glass or two of wine and some food.

Hannelie de Beer (Qotho Minerals), Colwyn van der Linde (TCM Research), and James Vaughan (University of Queensland)

Tawona Murasiki (Rossing Uranium Mine), Hector Mapheto (Erudite Projects), Eugene Mkhize (SENET), and friends

The next morning began with conference chairman Rasoul Hassanalizadeh welcoming us all to the event. Unfortunately, Rasoul could not make it to the conference in person, but it was no problem to link up with him remotely.

We then had a presentation from the current SAIMM President, William Joughin, giving us the history of the SAIMM, as well as it's current objectives and a breakdown of it's membership.

William Joughin (SRK Consulting) and Kathy Sole (Consultant)

Following on from William, we began Session 1: Exploration, geology, and mining of selected REE ore deposits. The Keynote Address was an online presentation by Okay Çimen, associate professor and a senior geologist at Munzur University, Turkey. Dr Çimen presented, "Rare earth element deposits and occurrences in Turkey: Opportunities and limitations for international investors".

This was followed by two more papers before the morning coffee break: "An assessment of rare earth elements in borehole cores from the Ermelo, Witbank and Waterberg Coalfields, South Africa: Focus on the mode of occurrence", presented by Duduzile Modiba from the University of the Witwatersrand and the University of Johannesburg, and "Rare earth market intelligence: Magnets defining the outlook" presented by Katlego Matlou of Project Blue.

Helmut Mischo (TU Bergakademie Freiberg), Lucia Radovanovic (Embassy of the Republic of Namibia, Berlin), and Rainer Ellmies (Gecko Exploration)

After coffee, the presentations continued with Louis Schaarschmidt of TU Bergakademie Freiberg presenting "Challenges and opportunities for rare earth element mining in underground mines" and Rhulani Hlungwane of the University of Johannesburg presenting "Stratigraphic distribution of rare earth elements within the Soutpansberg coalfield, Tshipise sub-basin, South Africa"

They were followed by another Keynote Address, this time from Petrus van Staden, a self-employed Hydrometallurgist who was sponsored by Wood to attend the conference. Petrus presented "How well does the great demand for REEs translate into great business opportunities for producers?

Petrus van Staden (Hydrometallurgist) and Hans de Waal (Glencore Technology)

Next up was an online presentation, "Enrichment of rare earth elements in No. 6 coal seam from the Limpopo Coalfield, South Africa", by Sanki Biswas of the University of Johannesburg, followed by "Overview of the Eisenberg Project in Namibia" presented by Kabwika Bisaka of Broadmind Mining (see photo below).

 

Kabwika Bisaka of Broadmind Mining

Kabwika was followed by  "Bonya exploration Twyfelskupje world class rare earths projects in South Namibia" presented by Katwali Nambala of Shali Group Holdings.

After this packed morning, we broke for lunch, where I again had an opportunity to network.

Jaco du Toit (MET63) and Olga Bazhko (Mintek)

Simphiwe Ndhlazi (Alfred H. Knight), Sidney Martin (Broadmind Mining), and Moses Pius (Alfred H. Knight)

Nontle Mniki (Council for Geoscience), Duduzile Modiba (University of the Witwatersrand), and Agnes Modiga (Mintek)

After lunch we went into Session 2: Processing and refining. The Keynote Address "REEs processing" was given by Deependra Singh, Chairman and Managing Director of IREL (India) Limited.

Then we had 3 presentations before the afternoon coffee break. First up were two presentations from Olga Bazhko of Mintek and Johanna van Deventer of Purolite: "Application of ion exchange technology for the upgrading and purification of rare earth elements" and "Recovery of rare earth elements from low concentration acidic streams using ion exchange resins".

They were followed by an online presentation given by Taswald Moodley of Mintek: "Laboratory scale concentration of low-grade monazite beach sand – a pH dependency study".

Sean Scott (MET63), Johanna van Deventer (Purolite), and Randall Crisp (Carl Zeiss)

After the coffee break, we had "Model development for the ultrasound assisted alkali-acid leaching of rare earth elements from high ash coal from the Waterberg coalfield" presented by Agnes Modiga of Mintek and "Flowsheet development of two distinct rare earth minerals bearing heavy mineral sand ores" presented by Etienne Raffaillac of Mineral Technologies.

There was then an icebreaker quiz, which I confess I didn't attend as I needed to get back to my hotel and change into some warmer clothes, ready for the Conference Dinner at the Tiger Reef Beach Bar and Grill.

Waiting for the coach to the conference dinner, I met Fisokuhle Masondo (CM Solutions), Roux Wildenboer (Rainbow Rare Earths), and Given Khosa (CM Solutions)

Sidney Martin, Executive Chairman of Broadmind Mining, who sponsored the Conference Dinner

Winners of the ice breaker quiz being presented with their prize by Jolene Saaiman of Mineral Technologies (left)

A selection of photos from the Conference Dinner at the Tiger Reef Beach Bar and Grill, including
entertainment from fire dancers

The second day of the conference began with an address from Veston Malango, CEO of the Chamber of Mines in Namibia, who gave us an overview of the mining industry within the country at the present moment.

Veston Malango, CEO of the Chamber of Mines in Namibia

Session 3: Recovery from secondary resources then began with a Keynote Address from James Vaughan of the University of Queensland, "Mary Kathleen tailings derived rare earth concentrates via double salt precipitation and caustic conversion".

James was followed by three more presentations before the morning coffee break: Rethabile Maphoso from the University of the Witwatersrand with "Critical Raw Materials: Characterisation and froth flotation as a preconcentration technique of weathered and non-weathered coals discards from Mpumalanga", Nontle Mniki from the University of Johannesburg with "Geochemistry and mineralogy with a focus on rare earth elements from coal discards occurring in the Ermelo Coalfield, and Roux Wildenboer of Rainbow Rare Earths with "Extraction of rare earth elements from Phalaborwa phosphogypsum".

Left: Olga Bazhko (Mintek) and Roelf Sandenbergh (University of Pretoria)
Right: Kemane Kgwete (Minersa)

Session 3 continued after coffee with an online presentation from Mark Williams-Wynn of EWaste Africa, "Development of a modular LPX Plant for efficient extraction and environmental remediation of mercury-contaminated luninophosphor powders" and Rampfumedzi Tshilidzi of Mintek with, "Characterisation, quantification and recovery of rare earth elements (REEs) in South African coal fly ash samples".

We then launched into Session4: Processing and refining/beneficiation with three more papers before we broke for lunch.

Sean Momberg of ProProcess Engineering began the session with "Strategic considerations in the construction of a rare earth facility in Angola: A comparative analysis of modular ex-works construction and traditional stick-build approaches", followed by Chiara Carrozza of Italmatch Chemicals with "Rare earth extraction with IONQUEST 801 initial modelling development", and Tebogo Mokgomola of Mintek presenting "Development of a physical separation preconcentration process for the extraction of rare earth bearing ore".

Kagiso Seleke (AECI), Filip Dutoy (Italmatch Chemicals), and Chiara Carrozza (Italmatch Chemicals)

After lunch, we had two more presentations before the conference finished. The scheduled paper from the University of Cape Town was not able to take place, and instead Sanjey Bhoowanpursadh of DMT Group presented "Financial challenges in the African critical minerals revolution". 

The conference closed with another paper from Mintek, presented by Buhle Xakalashe and entitled "Rare earth elements research conducted at Mintek".

I would like to thank the organisers of this event, the SAIMM, for allowing me to attend and for a very enjoyable couple of days. A special mention must also be made to Selo Ndlovu from the University of the Witwatersrand who stepped in at the last minute to perform the duties of the Conference Chair.

MEI are organising Critical Minerals '24 in Cape Town from November 14-15, 2024 and I hope to see you there!

Fundamental limits of the supply chain of critical metals and minerals within the circular economy

There is a lot of talk about greening society, greening the supply chain, circular economy etc. The question that needs to be answered is how green is all of this and what shade of green (or grey) is achievable.

This will be the question discussed by Prof. Markus Reuter in his keynote lecture at Critical Minerals '24 in Cape Town in November. The key role of metallurgy and minerals processing will be discussed in applying simulation methods and theory to understand the greenness of systems and in fact what the limits are of the system.

Various cases will be shown, covering process metallurgy, recycling, design for recycling, etc., analysing the system on the basis of exergy and footprinting the system. A large body of published information will be highlighted, rooted in industrial practice, to illustrate how far the industry has also progressed to address green issues fundamentally.

Markus Reuter has been a long time consultant to MEI's sustainability conferences. He is Chief Expert and  Professor at the SMS group GmbH, Germany, Adjunct Professor on Recycling at Curtin University, Australia and Honorary Professor at the Technical University Bergakademie Freiberg, Germany, where he was a Director for almost five years. 

Markus has been ranked number 8 in the world in the field of recycling by ScholarGPS, which ranks scholars whose works are of profound impact and of utmost quality (posting of 9th May 2024). In 2014, he received the 1st Prize Publication Award for Handbook of Recycling, by the International Solid Waste Association.

The keynote will provide a great opening to MEI's inaugural Critical Minerals conference, which has a full 2-day programme immediately following Process Mineralogy '24.

#CriticalMinerals24