Global from UK – MEI Sustainable Minerals wrap

The sixth international Symposium on Sustainable Minerals (Sustainable Minerals ’21), organized by Minerals Engineering International (MEI), was held online from 21st-24th June.

CEEC is proud to be an industry advocate of the highly regarded Sustainable Minerals conference, which highlights the many options and advances to improve the way we design, operate and integrate the steps in mining and plant processes with the aim of increasing productivity, reducing waste, improving energy efficiency and water use, and engaging communities.

The conference program had eight sessions on the topics of Circular Economy, Recycling, Acid Mine Drainage and Waste Waters, Tailings, Innovation for the future, Biotech, Waste Processing and Energy. The program is available here.

This year’s event also featured CEEC’s global announcement about its 10-year anniversary and the launch of its webinar and video series. MEI’s Dr Barry Wills said: “We are proud to have as one of our Industry Advocates, the Coalition for Eco-Efficient Comminution (CEEC), a highly respected organisation founded 10 years ago thanks to the vision of Gekko’s Elizabeth Lewis-Gray. CEEC brings industry leaders together to tackle the challenges of comminution, which accounts for around 3% of the world’s electrical energy consumption, and to mark their 10th anniversary we were pleased to share a short video from CEEC.”


The conference featured some excellent keynote lectures discussing important topics. The first keynote, ‘A Life Cycle-Based, Sustainability-Driven Innovation Approach in the Minerals Industry’, was presented by Professor Luis Marcelo Tavares of the University of Rio de Janeiro as part of the first technical session on the circular economy. His research is focused on modelling and simulation of comminution and mineral concentration processes, the fundamentals of particle breakage as well as sustainability in the minerals industry.

Dr Wills wrote in the MEI blog that this presentation showed that “sustainability in mining must be envisaged from a more comprehensive perspective that involves the management of primary and secondary resources and that prioritises the adoption of innovation beyond a techno-economic mindset.”

The second keynote, ‘Why mine closure should not be considered just an environmental issue’, was delivered by Professor Anna Littleboy of the Cooperative Research Centre for Transformations in Mining Economies (CRC TiME) in Australia as part of the session on innovation for the future.

Dr Wills noted that this presentation drew on two years of consultation with industry, government and community representatives to establish an industry-led cooperative research center in Australia that considers mine closure as an agent of regional development, rather than as the end of the mining value chain. “The paper presented the challenge of mine closure through the lens of systems thinking and offered a new way of thinking about the challenges to be addressed to better link mine closure to successful post mining outcomes for all stakeholders,” he added.

“Addressing these challenges requires new ways of thinking about how the operation of a mine impacts on ecosystems, livelihoods and regions long after the mine has gone – and then incorporating this new way of thinking into the decision systems that drive project valuations, operational planning, regulatory determinations, regional planning, community engagement and institutional hierarchies. The issue of mine closure affects social performance, regional impact, residual risk, mine planning, and future investment.”

The final keynote, ‘The war on waste: How could the mining industry respond?’, was presented by Dr Anita Parbhakar-Fox of the Sustainable Minerals Institute (SMI) at the University of Queensland in Australia as part of the waste processing session.

Dr Wills noted that this presentation showed that there is an international ‘war on waste’ waging whereby industries and consumers are becoming increasingly aware of the environmental impacts our linear ‘take-make-dispose’ economy facilitates. He added: “The promotion, and in some cases adoption, of circular economy principles has grown in recent years but how has this impacted on the mining industry and, more specifically, mine waste management?”

The presentation noted that fundamentally, we mine waste, not ore. “The large tonnages of waste rock handled at mine sites, particularly open cuts, illustrates this,” explained Dr Wills. “Continued mining in this manner is expected to meet the metal demands of our growing global community. It is therefore imperative that the produced waste is characterised to determine if it can be further utilised following circular economy principles or if it is truly waste how can it be disposed to minimise environmental risk?”

Notable papers

Dr Mathilde Robben of Tomra Sorting in Germany gave a presentation on the topic of mining, sorting and the circular economy. She stressed that the transformation from a linear economy to a circular economy is of direct relevance to the mining industry, as it is a major producer of minerals and metals, as well as a big consumer of energy, water and chemicals.

While consumer goods companies dominate the circular economy conversations, it is essential that the minerals resource industry contributes to an economy that is efficient in how it extracts, produces, consumes, recovers, and recycles resources. Dr Wills said that she showed that sensor-based sorting solutions have proven their worth not only as a ground-breaking technological innovation. He added: “Considering that grinding is the most energy-intensive part of the production cycle, implementing sorting in the early stages of processing reduces waste material and shrinks the carbon footprint while increasing profitability.”

In addition, implementing sorting results in a smaller footprint for the operation, the need to use chemicals in beneficiation plants is reduced, and the efficiency and quality of valuable ores recovery are maximized.

Dr Daniel Parvaz, director of Lightning Machines Limited, spoke about breakage characteristics of incinerator bottom ash (IBA) in the high voltage pulse power (HVPP) process. Recent research indicates the pre-concentration potential of the HVPP treatment by the accumulation of comminution energy towards conductive target phases.

IBA is comprised of heterogeneous particles, and metals and rubble can be trapped within melting products. Dr Parvaz presented a study on the HVPP breakage characteristics of IBA, where individual particles of various particle sizes were treated at increasing HVPP energies.

The results confirmed a feed size effect, in addition to the preferred breakage of metal-bearing particles. Particle breakage behaviour is determined by energy delivery mechanism, meaning that when conductive phases are present, the discharge path is forced into particles, giving efficient size reduction and metal liberation. In metal-free particles the discharge travels along the surface, resulting in limited size reduction with a specific fracture pattern.

He concluded that the preferential liberation of locked metals without excessive crushing provides a sustainable recycling solution for bottom ash, and it has been confirmed in industrial scale.

Dr German Figueroa, a plant metallurgist at CSA Glencore in Australia, discussed the vital importance of student placements for mineral processing research scholars, noting that activities on site and direct interaction with experienced personnel not only provide industry-ready skills but also the foundation of sustainable practices.

He added that while students benefit from the host company through skills acquisition of all kinds, the host company can benefit through research knowledge-transfer, cost efficiency, and international relationships.

In 2016, postgraduate students from the Julius Kruttschnitt Mineral Research Centre (JKMRC) in Queensland, Australia, participated in the comminution and flotation surveys at the concentrator plant in Francisco I. Madero, Peñoles, Mexico. They also had the opportunity to test their research projects at industrial scale.

According to Dr Wills, Dr Figueroa described the main activities and challenges experienced from the education point of view during the process, preliminary metallurgical results, research at industry application, and concluded by describing the overall student experience, which is a critical part of their personal and professional formation.

Along with the presentations, the conference featured 20-minute networking functions, where delegates were placed random into a group of up to three participants for five minutes. After five minutes, they would be moved to another group unless they chose to leave the networking session. Dr Wills said: “This is our way of recreating those random meets over a cup of coffee at a conference!”

The final day of the conference also featured a panel discussion on the topic ‘What are the limits to achieving a circular economy?’, which was chaired by conference consultant Professor Markus Reuter of the SMS Group in Germany. The conference’s keynote speakers, Dr Anita Parbhakar-Fox, Professor Anna Littleboy and Professor Luis Marcelo Tavares, were panellists along with Dr Peter Radziszewski of Rampart Detection Systems in Canada.

The panel was broadcast live, and conference attendees could submit questions for discussion. Dr Wills said: “There was very wide ranging discussion in this 100 minute session, with very lively interaction from conference delegates. As with all the presentations, the panel discussion is available on demand for all registered delegates until the end of the year.”

Takeaways and proceedings

CEEC acknowledges MEI and all conference authors, sponsors and contributors for another excellent, informative conference, and thanks Dr Barry Wills for his excellent summaries of each day of the conference on the MEI blog which CEEC drew from for this update.

He noted that despite the time zone problem, presentations were well attended, and the facility for viewing recordings on demand at a more convenient time led to extremely useful online discussions.

The presentations from Sustainable Minerals ’21 will be available online until 31 December 2021, including all 60 presentations from 24 countries, the panel discussion and three keynotes. You can register to view the content here.

“It is evident from the presentations over the past four days that to sustain the supply of the many minerals that are involved in clean and renewable technologies, ranging from base metals such as copper and zinc to strategic minerals such as rare earths and cobalt, will require more mining, innovative processing technologies and more emphasis on recycling,” said Dr Wills. “The Sustainable Minerals series is thus of vital importance in bringing people together to discuss these important issues, so a decision has been made to make the conferences annual events, the next one, Sustainable Minerals ’22, scheduled for July 11-14 next year.”

More information is available about Sustainable Minerals ’22 is available on the website here. The call for abstracts has been issued, and you can submit an abstract for consideration here until the end of April 2022.