The continuing evolution of mineral processing

In the middle of the 19th century mineral processing as a professional discipline did not exist. Simple upgrading of ore by hand sorting and gravity concentration was handled by lowly paid mine workers, often women, and it wasn't until the early 20th century, with the introduction of froth flotation, that mineral processing became a recognised profession, with chairs in the subject springing up in universities around the world. 

There were some significant innovations at this time, such as the introduction of tumbling mills to replace stamp mills, but evolution in the first half of the century was slow, and by the 1970s little had changed in the design and operation of mills since the 1930s.

Typical mid 20th century ball mill classifier layout

Evolution was given a boost in the 1980s with the rapid development of computers, and the pioneering of mathematical modelling and automatic control, which led to the trend to increasingly larger flotation machines and grinding mills, and the widespread use of SAG mills.

The 21st century has seen a rapid increase in innovation, with the introduction of novel flotation machines, such as the Jameson Cell and the Hydrofloat, and grinding circuits incorporating high pressure grinding rolls and stirred mills. Enhanced gravity concentrators and high intensity magnetic separators have also played their part and there is now an increase in the use of sensor-based electronic sorters to pre-concentrate ores and reduce energy and water costs.

Now, as we enter the 4th industrial revolution, the 'green' revolution, mineral processing is recognised as one of the most important technologies in satisfying the increasing demand for all metals, particularly those that are critical in the manufacture of renewable energy sources, and for electric vehicles. There are tremendous challenges facing mineral processors, particularly in the need to recycle as much of these metals as possible from end of life resources, such as electronic waste, which will be a focus of July's Sustainable Minerals '22. At last month's Physical Separation '22 panel discussion, it was noted that processes such as gravity, flotation and magnetic separation will need to be integrated more in future as ores become more complex, and how mineral processing will evolve in the future will be the subject of the 2 hour panel discussion at IntegratedMinPro '22 which begins online in 2 weeks' time.

The panel will be chaired by Stuart Saich, of conference sponsor Promet 101. The conference's keynote speaker, Osvaldo Bascur, will be joined on the panel by Stephen Rayward, of MIDAS Tech International, Australia and Diego Mesa, representing Imperial College, UK, and Aminpro, Chile. The discussion will be live streamed and delegates will be invited to submit questions to the panel.

The conference will be held online over two days, June 13-14 and recordings of all the presentations and the panel discussion will be available on demand to registered delegates for a period of 6 months.

#IntegratedMinPro22

Process Mineralogy '22: Final Call for Abstracts

Join us in beautiful Catalonia, Spain, in November, for Process Mineralogy '22, MEI's first face-to-face conference since the start of the pandemic.

If you would like to present a paper at the conference, then please submit your abstracts by June 7th (more information on the posting of 28 March). All presenters will be invited to submit papers for peer-review after the conference, and accepted papers will be published immediately in the first available regular issue of Minerals Engineering, and included in the Virtual Special Issue of the conference on ScienceDirect.

The conference will be held at the Meliá Sitges Hotel, in Sitges, just 20 minutes by road from Barcelona airport and 30 minutes from the centre of Barcelona. The hotel has spectacular views of the Garraf Natural Park and the Mediterranean sea, and the Congress and Convention Centre has high speed WiFi internet in all its rooms.

As with all previous Process Mineralogy conferences there will be an associated exhibition, and if you would like to exhibit, or sponsor the conference, please contact jon@min-eng.com for details.

#ProcessMineralogy22

Recycling critical metals from e-waste

The programme for the final day of July's Sustainable Minerals '22 is devoted to critical minerals, those that  are essential to the green revolution, but whose future supply cannot be guaranteed due to scarcity and geopolitical factors. The day will end with a 2 hour panel discussion "Will the production of critical minerals be sufficient to satisfy the green revolution". The image below from the European Chemical Society, shows very clearly the elements in the Periodic Table which are most at risk.

Primary mining alone will not be enough to satisfy future supplies and major research efforts are being made around the world to develop methods of recycling these minerals from end of life commodities. The second day of the conference will focus solely on recycling and we welcome further input from workers involved with this crucial area of research.

Much of the research into secondary sources is focused on e-waste and the Royal Society of Chemistry (RSC) has recently said that the recycling of e-waste must urgently be ramped up because mining the Earth for precious metals to make new gadgets is unsustainable. One study estimated that in 2021 the world's mountain of discarded electronics weighed 57 million tonnes. All the while, the amount of e-waste generated is growing by about two million tonnes every year, and less than 20% is collected and recycled. 

Over 60% of the world’s population owns a mobile phone and smartphone adoption continues to rise in developing countries around the world, and as technology continues to improve so will the demand for the metals necessary for the next generation of smartphones, most smartphones carrying roughly 80% of the stable elements in the periodic table.

Breakdown of critical metals in a smartphone
Source: University of Birmingham

"Our tech consumption habits remain highly unsustainable and have left us at risk of exhausting the raw elements we need," said Prof Tom Welton, president of the RSC, adding that those habits were "continuing to exacerbate environmental damage".

So do try and join us online in July for Sustainable Minerals '22, and if you have something to say it is not too late to submit an abstract.

#SustainableMinerals22

Interesting news and people at the Cornish Mining Sundowner

There was a great turnout of around 25 at last night's sundowner at Falmouth's Chain Locker, with a number of new faces adding to the regular attendees.

Some of the sundowner 'regulars'

It was particularly good to welcome Mohammad Hadi Mohammadi from Afghanistan. As an academic he was vulnerable to the Taliban, and the Camborne School of Mines (CSM) and the CSM Trust arranged his appointment at CSM where he will work with CSM's Prof. Frances Wall on a 2-year research fellowship. The move was facilitated by the Council for At-Risk Academics (CARA), a charitable British organisation dedicated to assisting academics in immediate danger.

Mohammad with Frances Wall and the CSM Trust's Tony Batchelor and Nick Clarke

It was also good to meet representatives from London's Natural History Museum, who are in Cornwall for project meetings assessing the geology and processing of lithium deposits in the county.

The Natural History Museum visitors

I was pleased to offer my congratulations to a sundowner regular, and old friend, Mike Hallewell, who has been appointed as Consulting Metallurgist for Cornish Metals and so will be leading the process development effort for the impending studies for the regeneration of the old South Crofty tin mine.  Mike is the ideal person for this role as he worked in the tin industry from 1984 to 1998 and played a key role in the development of the Wheal Jane flowsheet for treatment of South Crofty Ore at the Wheal Jane Processing plant near Truro. Mike led the team that was responsible for the successful implementation of the Mozley MGS technology (posting of 4 June 2015) as a final stage of cleaning on tin flotation, a success that was copied by many tin mining operations globally at that time.

Mike Hallewell (2nd right) with fellow mineral processors BW,
Dave Goldburn (Holman-Wilfley) and Andy Wilkinson (Metso Outotec)

Andy Wells

Mike's mentors at South Crofty and Wheal Jane were Tony Elliott and Andy Wells respectively and he said that he always has and will remember them for their metallurgical standards. Mike took over as Mill Superintendent from Andy Wells in 1991 when Andy left to join the Neves-Corvo zinc-copper mine in Portugal and Mike went on to become the longest serving Mill Manager (7yrs) at Wheal Jane.

Mike also had some sad news, of the death earlier in the year of Andy Wells. Andy left Neves-Corvo in 1996 and returned to the UK to become principal metallurgist and later a director of IMC Mackay & Schnellmann. In 2004, he joined the London-based consulting partnership, Saint Barbara, where he continued his engagement in minerals projects as principal metallurgist, manager and then as owner. A full obituary is on the IOM3 website.

Missing from the usual attendees was Nick Wilshaw, as on the previous evening he attended a mineral processing sundowner 200 miles away in Cardiff, hosted by Maelgwyn Mineral Services, with staff from MMS, SRK Consulting, and Nick's Cornish company Grinding Solutions.

The Cardiff sundowner: Liam Macnamara (SRK), Dave Pattinson (SRK), Dan Abraham (GS),
James Gaydon (GS), Nick Wilshaw (GS), Mike Battersby (MMS), Steve Flatman (MMS)
John Willis (SRK) and Ryan Schultz (MMS)

Liam Macnamara has recently joined SRK after many years with FLSmidth, and Ryan Scultz is a recent addition to the MMS Cardiff Office, after spending some time at MMS in Johannesburg. Ryan’s responsibilities at MMS, from his 10 years of operational experience in South Africa on PGMs and chromite sands and the Democratic Republic of Congo on copper and cobalt, are to implement all the required systems around the Aachen technology, while building and maintaining client relationships, by ensuring the best performance of the MMS technology through regular consultations and servicing.

The next sundowner, at the Chain Locker, is on Thursday June 16th from 5.30pm. We will be very pleased to see you if you are in the area.

@barrywills

A brief update on Metcelerate

Metcelerate is a two year Professional Formation programme for mineral processing engineers. It is online and requires a few hours of learning each week and equips metallurgical professionals with the knowledge and practical skills they require to manage effectively metallurgical processes, assess risk and identify opportunities to enhance value. 

The Metcelerate program took in its first cohort of 45 learners in July 2000. Attendees came from around the globe; PNG, Australia, Ghana, Suriname, Chile, Peru, Mexico, Canada and the USA. This cohort is now completing the course, and the next cohort start in July of this year.

Metcelerate's Chief Financial Officer, Prof. Jan Cilliers, has sent me this brief update, and full details can be found on the website:

The Metcelerate program was developed with industry, based on a review of current training and critical gaps. This established the core topics and course content. 

The 20-month Metcelerate curriculum has seven taught modules (51 weeks in total) and a final Project, world-leading subject matter experts (Finch, Hadler, Seitz, Holtham, Napier-Munn and Wills, amongst others) having developed the training material as slides, videos, papers and exercises. E-learning specialists transformed this into on-line training material.

Successful course completions earn digital badges for sharing on social media, and printable certificates. Badges are certified through the London City and Guilds Institute. 

The Metcelerate programme is offered through companies that sponsor their learners. It requires commitment not only from learners, but also from site mentors; assignments and project must be agreed, monitored and evaluated. Buy-in across the company structure is essential, and has been a major factor in the success to date. 

Prof Cilliers says that both learner and company feedback has been very positive.

The contribution of mineralogy to sustainability in the mine life cycle

It is well known that mining is an essential enabler to sustainable development. Understanding and appreciating the mineralogy of the ores and waste material we produce is a key component of this. In November's Process Mineralogy '22 in Sitges, Prof. Megan Becker, of the University of Cape Town will present a keynote lecture considering the contribution of mineralogy to sustainability through the mine life cycle, looking through the lens of the domains of process mineralogy, environmental mineralogy and medical mineralogy and their relationship to the pillars of sustainability - profit, planet and people, respectively. Using several case studies, Megan will show how the application of mineralogy and the tools used for characterisation have evolved over the decades from some of the early pioneering mineralogists to some of the most recent work where mineralogy is fully integrated into all aspects of ore and waste use and valorisation. 

Prof. Becker's research and teaching at UCT focuses on the application of mineralogical knowledge for the understanding, optimisation and prediction of key unit processes within the mining industry from techno-economic and environmental aspects. She has successfully integrated process mineralogy into the activities of the Centre for Minerals Research and other research groupings within the Chemical Engineering Department at UCT. She has close to 90 peer reviewed publications, and in 2018 she was nominated as one of the top 100 Global Inspirational Women in Mining. 

Megan is consultant to MEI's Process Mineralogy conferences and is a co-author of the JKMRC monograph Process Mineralogy, which was showcased at Process Mineralogy '17 in Cape Town.

Megan (centre) with co-authors Elaine Wightman and Cathy Evans

We look forward very much to meeting Megan again in Sitges, which is just outside Barcelona in Spain. It will be our first face to face process mineralogy conference since Process Mineralogy '18 in Cape Town. It will be great to see people in person again, and now is a timely reminder that the deadline for abstract submission is the end of this month. More details can be found on the posting of 28th March. Once again I thank our current sponsors, Bruker, Zeiss and Promet101, and our media partner, International Mining, for their support.

#ProcessMineralogy22