Friday, 17 January 2020

January's Cornish Mining Sundowner

Cornwall's capital city, Truro, was the venue for last night's sundowner, attended by around 25 regulars at the County Arms Hotel.
I was pleased to see Dave Dew and Pete Walsh, two of the Camborne School of Mines class of 1979, the first mineral processing graduates. Dave will be presenting the first keynote lecture at Biomining '20 in Falmouth next June. He will be discussing the limitations to the commercial application of biohydrometallurgy for the treatment of base metal ores and the rise of chloride heap leaching as a competitive technology.
With Dave and Pete
Dave, of Dewality Consultants, will also be a co-author of a paper discussing aspects of the bioleaching of a pyrrhotite-pyrite ore, with CSM's Professor of Sustainable Mining, Karen Hudson-Edwards (3rd right below).
Also in Falmouth in June will be CSM's Prof. Frances Wall (2nd right below) who will be co-author of a paper at Sustainable Minerals '20 overviewing the work in Cornwall on the MIREU Project. The project aims to establish a European mining network, involving 30 partners from 17 regions, and identify methods to ensure the continued sustainable supply of mineral raw materials throughout Europe.
Frances is currently much involved with the launch this week of the HiTech AlkCarb EU project outreach activity, ‘Technology Metals for a Green Future’. This on-line course is free to join and is aimed at non-specialists. So mineral processors might like to find out about geology and responsible sourcing, for example. Participants can do as much or as little of the course as they like. Over the four weeks, the leaders will explain what technology metals are – i.e. all the specialist metals like rare earths, lithium, cobalt, tin, tungsten, indium – that are essential now in low carbon and digital technologies (and which will be profiled at MEI's Hi-Tech Metals '20 in October). How ore deposits form will be covered in week 2, how they are mined and processed in week 3, and in week 4 the issues of responsible sourcing and making a circular economy.
It was, as always, an interesting sundowner, and the next one is in Falmouth, at the Chain Locker, on Thursday 20th February, at the usual start time of 5.30 pm.
But before then, as a number of our group will be in Cape Town in a couple of weeks time for Mining Indaba 2020, there will be a sundowner on Monday February 3rd on the Cape Town waterfront. We invite anyone with a Cornish mining connection to join us at the Ferrymans Tavern, from 5.30pm.  Photos from previous sundowners at the Indaba are shown below.
Cape Town 2004
2005
2016

Monday, 13 January 2020

Are modern flotation cells too big?

When I first saw the flotation plant at the Nchanga copper mine in 1969 I was impressed with the sheer scale of the operation, and the multitude of Denver Sub-A flotation machines arranged in parallel banks, each bank containing 20 1-m³ cells. A year later, what were considered to be huge 8.5-m³ Wemco Fagergen cells were introduced into the oxide flotation circuit.
When I made a return to Nchanga in 2012 all these cells had been replaced by much bigger machines, but even they were not of the size used on many large copper concentrators today. 
Nchanga's derelict former sulphide flotation plant
Nchanga's current sulphide roughers
The Applications Symposia of the last few MEI Flotation conferences have highlighted the continued increase in size of machines. The race to increase cell size has become almost a competition between manufacturers, the leading players being Metso and Outotec, who manufacture cells of over 600-m³ capacity, and FLSmidth, with the largest cell in the Western world, the 660-m³ SuperCell.
The FLSmidth SuperCell
At Flotation '19 Outotec described the commissioning of the first two Outotec e630 TankCells®, with 630-m³ of effective flotation volume, at Buenavista del Cobre Cu-Mo concentrator plant in Northern Mexico as the first cells in two existing rougher lines. Commissioning was finished in March 2018 and since start-up the plant has reported increased copper recoveries while maintaining the final grade.
Leading the race at the moment, however, is Chinese company BGRIMM Technology Group, who described the installation of the 680-m³ KYF-680 Machine, which is currently operating at the DeXing Copper Mine in China to reprocess the tailing.
But is the race ending and have machines now reached a limiting size? This was the question asked by Stephen Neethling, of Imperial College, UK, at Flotation '19, who showed that as cells get larger they become more carrying capacity constrained, while a paper from Eriez Flotation Division, USA, suggested that the approach of exploiting economies of scale and building increasingly larger unit operations is flawed, as there is a significant reduction in energy efficiency as the conventional tank designs become larger.

In last month's E&MJ, Carly Leonida conducted an excellent interview on flotation for the 21st century with Thierry Monredon, Metso's global manager for flotation. He felt that 600-m³ cells would definitely be the maximum size used in the foreseeable future, suggesting that it is often cheaper to have two banks of 300-m³ cells instead of one bank of 600-m³ cells.
Currently, it is operations with low grades and high throughput, for example, copper mines, that have opted for 600-m³ cells. “Grades have been decreasing, and to maximize efficiency, these operations need to have high throughput,” said Monredon. “In these cases, large diameter flotation cells are compulsory, but again, 600-m³ is really the limit. That’s clear for me, for our company, and I believe that’s what we’ve seen from our competition as well.”
So, what are your views on this?  I would be particularly interested in hearing from those of you who have had experience of working with such large machines.
 

Sunday, 12 January 2020

New Book: Electronic Waste and Printed Circuit Board Recycling Technologies

This book, by Muammer Kaya,  covers state-of-the-art technologies, principles, methods and industrial applications of electronic waste (e-waste) and waste PCB (WPCB) recycling. It focuses on cutting-edge mechanical separation processes and pyro- and hydro-metallurgical treatment methods.
De-soldering, selective dismantling, and dry separation methods (including the use of gravity, magnetic and electrostatic techniques) are discussed in detail, noting the patents related to each. The volume discusses the available industrial equipment and plant flowsheets used for WPCB recycling in detail, while addressing potential future directions of the field.

The book is available from Springer.

Thursday, 9 January 2020

Mining and Complexity: a new look at old concepts

This is the title of a 3rd keynote lecture which will be presented at Sustainable Minerals '20 in Falmouth in June. It will be given by Professor Anna Littleboy, an experienced research director, now at The University of Queensland's Sustainable Minerals Institute.  She specialises in resource sustainability and multidisciplinary integration.
Her program develops systems and processes to share value from resource endowment through new business models, technological and environmental innovation and enhanced social performance from the minerals sector. Anna works towards a minerals sector that uses less energy and water, produces fewer wastes and delivers shared value to communities.
With a background in earth and environmental science, Anna’s focus is on multidisciplinary integration to address the long term risks of disruptive technologies.   She has secured several multi-million dollar funding investments from Government and industry for minerals related research. 
In her keynote, Anna will show that the context in which mining finds itself has never been more dynamic.  Demand continues to grow to address population and poverty reduction.  New commodities and new jurisdictions are coming into play to enable new energy generation and economic development. 
To satisfy these needs expectations on the industry are at an all-time high – to transition away from fossil fuels, to maximise resource utilisation, to minimise wastes, to deliver value to affected communities, to disclose risks, to close and to support human development.   All these issues interact to form a complex system affecting us at local, national and global scales.  And yet, mining tends to be conceptualised as a linear process – through a value chain that progresses from exploration, approvals, construction, operations to closure and relinquishment.  What happens if we start looking at these activities in a non-linear manner?
Anna will present new analyses of global datasets to examine critical variables for the minerals sector as it transitions into the 2020’s.  Recent work has identified that the development of known orebodies is not limited by economics alone.   More than 75% of known copper deposits ($65 billion at 2019 market value) is prevented from development by issues that are not price sensitive such as social concerns, legal or permitting challenges.  This finding alters the risk profile for investors and mining companies and challenges the long held notion that the ability to develop an ore body is purely determined by market economics and the cost-price equation.
The lecture will present examples of how this is affecting the mining process and its contribution in a sustainable circular economy.  Examples of innovative approaches to by-product development, waste reduction and product stewardship will be presented, together with practices that seek to strengthen the relationship between mines and their communities throughout and beyond the mine lifecycle.
Finally, the paper will examine philosophically three issues limiting society’s ability to embrace minerals as a core component of a sustainable future.  Drawing on concepts from the social, geographical and organisational psychology disciplines, it will postulate the need to re-invent the relationship between mining and society – which is not something mining can do on its own.
There is a lot to look forward to in Falmouth in June, not only Sustainable Minerals '20, but also Biomining '20 which precedes it.
The latest updates on both conferences can be found at #SustainableMinerals20 and #Biomining20.

Sunday, 5 January 2020

Will the roaring 20s be the decade of the mineral processor?

As we enter a new year and a new decade what will be the main issues facing the world and the mining industry? Predicting the future is an impossible task, but it is fairly evident that climate change will be high on the agenda.
Few people now deny that climate change is a reality, but some question whether the current extremes of weather are due to natural climate cycles, totally due to human influence, or a combination of the two?
Interestingly 10 years ago, as we prepared to enter a new decade, the debate was as controversial as it is now. The main protagonist for a natural geological cycle was Prof. Ian Plimer, Emeritus Professor of Earth Science at the University of Melbourne, who contributed a long argument against anthropogenic global warming (AGW) on the blog in October 2019.
In the opposite corner, providing a strong case for AGW, was Prof. Stephan Harrison, an earth scientist who is Prof. of Climate and Environmental Change at the University of Exeter in Cornwall.  Ten years on, a recent paper by Prof. Plimer in The Spectator shows that his views have not changed and he concludes with "evidence from the past is why geologists regard human-induced global warming as total nonsense."
I am not altogether sure that there is such a consensus among geologists; I know some that do advocate a natural cycle, others that don't, and Plimer's arguments have been refuted by many reputable scientists, who accuse him of distorting or ignoring published research on many topics, and that his claims are not supported with evidence or peer-reviewed research.
Many scientists believe, maybe instinctively, that the cause lies between the two extremes. The basic problem is that the science is so immensely complex that maybe we will never know the exact cause, but we do know the effect, and if we believe that humans are at least part of the problem, then we should be doing something about it.
And we, the mining industry, will play a huge part if 'zero carbon' is ever to be attained. Leaving aside the ludicrous demands of Extinction Rebellion, the UN Paris Agreement requires humanity to reach net zero greenhouse gas emissions by the middle of this century and the UK has committed to attain this goal by 2050, the first major economy to do so. My article of 21st July last year cast doubts as to whether this is attainable, as to attain these goals will put enormous demands on what are very finite resources of raw materials.
In supplying the raw materials to build electric vehicles and renewable energy sources, as well as providing suitable alternatives to oil and gas for heating home and offices, the importance of mining cannot be over-emphasised and the most important technology within the industry is, and increasingly will be, mineral processing.
Mining activity must step up a few notches in order to attain the zero carbon goals but all at a time when grades of ore mined are falling and the mineralogy becoming more complex. Mineral processing has to adapt to these changes, and as well as treating primary ores, there must be more emphasis on treatment of secondary sources, such as old tailings, and also on recycling, which is fairly easy with metals such as copper, but tremendously difficult with some of the hi-tech metals found in tiny amounts in computers and mobile phones.
Ironically the mining industry is one of the most energy intensive industries. The energy problem will most likely be solved this century by nuclear fusion, but it is doubtful whether this will be viable by mid-century as a replacement for fossil fuels, as truly formidable engineering problems have to be overcome, so efforts must be made to reduce the energy which is consumed in mining and processing.
The most energy intensive component of mineral processing is comminution, and every effort is being made to reduce energy consumption in crushing and grinding, and this is highlighted by the programme for MEI's Comminution '20 conference in Cape Town in April. The conference begins with two keynote lectures on comminution energy, and energy is the focus for the whole of the first morning.
Comminution '20 is the first of five MEI conferences this year which are all pertinent to the increasing importance of mineral processing. Sustainable Minerals '20, in Falmouth in June, recognises that the rapid growth of the world economy is straining the sustainable use of the Earth's natural resources due to modern society's reliance on raw materials, and will highlight the crucial role of mineral processing in the quest for a circular economy.
There is much overlap between Sustainable Minerals '20 and Biomining '20 which immediately precedes it. Biomining '20 will focus on the latest developments in biohydrometallurgy and bioprocessing, not only for primary ore processing but for novel resources, such as mine and electronic wastes, and the bioremediation of mining-impacted environments.  The provisional programmes for these two conferences will be published later this month, so it is not too late to submit abstracts.
Falmouth, the venue for #Biomining20 and #SustainableMinerals20
A few decades ago, the metals which we now call Hi-Tech Metals, such as the rare earth element neodymium, were relatively unheard of.  Lithium was essentially a curiosity but the demand for this once minor metal will increase with the continuing development of electric vehicles. The rare earths and lithium are primary mined, but some of the once minor metals, such as gallium, germanium and indium, which are essential for our modern way of life, are by-products of base metal mining.
The importance of all the 'Hi-Tech' metals cannot be overestimated and in October the 2nd conference on the mineral processing and extraction of these metals, Hi-Tech Metals '20, will be held in Cape Town, and will be immediately followed by Process Mineralogy '20, focussing on an area which is of increasing importance as mined ores and secondary deposits become ever more complex.
And to end the first year of the new decade the International Mineral Processing Congress will be in Cape Town in October, following the two MEI Conferences. This will be a great opportunity for minerals engineers of all disciplines to come together to discuss future needs and problems.
Cape Town, the venue for #Comminution20, #HiTechMetals20, #ProcessMineralogy20 and #IMPC2020
On behalf of us all at MEI, I would like to wish you all the very best for 2020, and we hope to catch up with as many of you as possible during the year.

Tuesday, 31 December 2019

Recent comments

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

Flotation '19: the final day
Flotation '19: applications symposium Day 1
2018 MEI Award to Zhiyong Gao
Flotation '19: fundamentals symposium Day 1
Action needed to raise the profile of mining education
Is zero carbon by 2050 attainable?
Kimberley: South Africa's historic diamond city
Towards 2050: visions of the future
Flotation '19: final report
Are these WASET conferences just a scam?
A nostalgic journey through Matabeleland on the Rovos train
Travels in Peru
Death of Victor Bryant: a true hands-on mineral processor
Adventure in Tanzania, 40 years ago today
Return to Chingola

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