Monday, 24 April 2017

Water, water, everywhere.....

Water is necessary for life to exist at all. Every single life form on earth, from the single celled organism through the most complex organisms, relies on water for sustenance. Water makes up most of the world and the planet is seventy five percent water. Some 97.5% is saline water largely in the oceans, so that only 2.5% is fresh water and useful for human needs. Fresh water is a renewable and variable, but a finite natural resource. The demand for water is driven primarily by population and concomitant economic growth. Overall, some 70% of the water withdrawn from the environment is used in agriculture, 20% by industry,7% by households and 3% by mining. Future water requirements are predicted to grow considerably, while supplies will remain relatively constant or decline due to over pumping of aquifers, changing weather patterns and increased water pollution and contamination. While all regions will experience water scarcity to some degree, there are some countries where it will become more critical leading to conflict between consumers.
Mining activities are often located in remote, arid environments, with limited access to high-quality water. Water rights in these regions are extremely contentious issues, in some instances leading to violent confrontation. This situation has the potential to only get worse because competition for ‘scarce’ water resources will increase with local population growth and agricultural land usage. Water used at mining operations comes from a variety of sources and the quantity and quality of the water varies from mine-site to mine-site. Mining impacts on water quantity and quality are among the most contentious aspects of mining and mining development. The main problem for the mining industry is to generate confidence in developing a responsible, sustainable and transparent water management strategy that is recognized as such by all stakeholders. 
This will be the subject of a keynote lecture at Sustainable Minerals '18 in Namibia next year, by Prof. Rob Dunne. Rob will provide an overview of water in the wider global arena and compare this to how the mining industry has dealt with water stewardship over the last couple of decades, and what the future may hold.
Robert Dunne was the Fellow Metallurgy at Newmont Mining Corporation before he retired at the end of 2013. Prior to this he held the position of Group Executive-Metallurgy Development and Technology. Over the last 35 years Rob has worked for a number of mining companies including Newcrest Mining, Anglo American, Anglovaal and Mintek. He has authored and co-authored over 80 papers and has been an invited conference plenary speaker. Water in the mining industry has been a focus over the last 10 years and Rob has given three plenary talks on this subject. He was nominated as a SME Henry Krumb lecturer and delivered a plenary talk on water to local USA branches of the SME. He is an Adjunct Professor at both Curtin University (Gold Technology Group) and Queensland University (JKMRC), Australia.

Saturday, 22 April 2017

Hayle Estuary to St. Ives

One of my 10 recommendations for spending some time in Falmouth (posting of 11th March 2015) was a train ride from Falmouth to Penzance (via Truro) and maybe then on to St. Ives (via the branch line at St. Erth).
If you enjoy a beautiful coastal walk, then another option is to take the train from St. Erth to St. Ives, but alight at the first stop, Lelant Saltings, which is on the estuary of the River Hayle.
Estuary of the River Hayle at Lelant
From here it is a relatively easy 4 mile walk to St. Ives, the coast path being accessed by crossing the West Cornwall golf course, and passing the 15th century St. Uny's church, where Richard Mozley is interred.
Crossing the golf course to the coastal path
Once on the coast path there are great views across the estuary to Godrevy lighthouse and then the huge and lovely Porthkidney Sands.
The Hayle estuary and distant Godrevy lighthouse
Porthkidney Sands

Once past Carbis Bay it is a gentle stroll to St. Ives, which can be extremely crowded in the summer months (a good reason for taking the train, as driving in the narrow streets can be a nightmare!). If you wish to linger, there are many fine restaurants, but you might wish to sample a Cornish pasty from one of the many "award winning" pasty shops, but be careful if you eat outdoors- the very large herring gulls here can be vicious and opportunistic- no wonder the original short story "The Birds" was set in Cornwall, not California as in the famous film. 
Carbis Bay
Approaching St. Ives
From St. Ives station take the short trip back to St. Erth, wait for the mainline train to Truro, and then change for Falmouth- a great day out!

Friday, 21 April 2017

An update on the forthcoming merger of Minerals Engineering and IJMP

The merger of Minerals Engineering and International Journal of Mineral Processing (IJMP) will take place in January 2018 (see posting of 21 December 2016).
I will remain as Editor-in-Chief of the merged journal, and the co-editors will be Dr. Pablo Brito-Parada, of Imperial College, UK, the current Editor of Minerals Engineering, and Prof. Kristian Waters, of McGill University, Canada, who is currently an editor of IJMP.
From 1 May 2017, submissions to IJMP will close and prospective authors should instead submit their papers to Minerals Engineering online.

Twitter @barrywills

Thursday, 20 April 2017

A Rising Star in Falmouth

Four weeks ago Anita Parbhakar-Fox, husband Nathan, and their two sons, arrived in Cape Town to present papers at Process Mineralogy '17. They had been severely delayed on their long flights from Tasmania-Melbourne-Singapore-Johannesburg-Cape Town, as Nathan had to return to Tasmania to collect the children's birth certificates.
Anita and family relaxing at the Vineyard Hotel after their epic journey
This is a good opportunity to remind any of you who are travelling to a Cape Town conference, and bringing your family for a holiday in this beautiful area, that the immigration rules introduced by South Africa in June 2015 require parents travelling with children (under 18) to show the child’s full unabridged birth certificate, which should list the child’s details and both parents’ details.
Anita is a great networker, one of the reasons that we chose her as one of MEI's Rising Stars, and all this week she and Nathan have been in Cornwall, as guests of Process Mineralogy '17 sponsor Petrolab, based in Redruth. The University of Tasmania and Petrolab are collaborators on a project funded by the Australian Academy of Technology and Engineering, aimed at refining test procedures to assist the mining industry with prediction and management of acid rock drainage. This was initiated via a meeting at Process Mineralogy '14.
It was great to catch up with Anita and Nathan together with James Strongman and Chris Brough, of Petrolab, this lunchtime at the Gylly Beach Cafe, on Falmouth's Gyllyngvase Beach, opposite MEI's conference venue the St. Michael's Hotel.
Gyllyngvase Beach with Nathan, Anita, Chris and James
Twitter @barrywills

Tuesday, 18 April 2017

Three more major sponsors for Comminution '18

We have great corporate support for next year's Comminution '18, so this is building up to another great event.
The latest sponsors are regulars, the giant international company Outotec, who are sponsoring the comminution series for the 3rd time, as are Chinese company Chemco Advance Material, a manufacturer of ceramic micro-beads. We also welcome back, for the 4th time, Korean company Cenotec, also a ceramic bead manufacturer.
Current Comminution '18 sponsors
Cape Town next April should not be missed if you have any interest in comminution. If you would like to present a paper, please submit your short abstract by the end of September.
Check out the report on Comminution '16.
Coffee break in the exhibit area at Comminution '16

Sunday, 16 April 2017

Praa Sands to Prussia Cove

The long sandy beach of Praa Sands is only a 35 minute drive from Falmouth, and the fairly easy 2 mile walk from Praa Sands to Prussia Cove is one of Cornwall's best, taking in some superb clifftop scenery and a number of rocky coves, notably Bessie's Cove and Piskies Cove in the area known as Prussia Cove. This was once one of the most intensively used areas for smuggling brandy as the small beaches are difficult to see from the top of the cliff. Bessie's Cove was used as one of the locations for the 1970s Poldark series.
Praa Sands
 
Piskies Cove
Cudden Point
Those with a keen eye will also notice a subtle change in geology from the metamorposed sediments, including slates, near Praa Sands to the beginning of the Land's End granite which forms Cudden Point above Prussia Cove.

Wednesday, 12 April 2017

IOM3 Awards

Naturally I am proud and delighted to have been awarded the IOM3's Medal for Excellence, one of three of the Institute's Premier Awards this year to mineral processors (full details on MEI Online).
Congratulations to Derek Barratt for the award of the Futers Gold Medal and Tony Francis for his Outstanding Contribution Award.
When I was awarded the IMPC's Distinguished Service Award in Santiago in 2014 (posting of 23rd October 2014), I accepted the award on behalf of my wonderful family, aka the small and highly professional MEI team. And now I do so once again, as well as thanking all our many friends in the minerals industry who continue to drive our ambitions.
MEI- Barry, Amanda, Barbara, Jon

I am particularly appreciative of the message that I received yesterday from Prof. Cyril O'Connor, Chairman of the International Mineral Processing Council, which he has requested that I publish on behalf of the IMPC:

It is with great pleasure that I have learnt that the Institute for Materials, Minerals and Mining (IOM3) in the UK has, in its 2017 awards list, announced that our colleague and friend Dr Barry Wills has been awarded the IOM3 Medal for Excellence. The International Mineral Processing Council and delegates to the XXVII IMPC in Santiago, Chile, in 2014 will all be very much aware of the enormous contribution which Barry has made to the discipline of Minerals Processing having been the recipient at that Congress of the IMPC Distinguished Service Award in recognition of his “outstanding and noteworthy contributions to the field of Minerals Processing over a sustained period”.

Barry has for many years been a loyal supporter of International Mineral Processing Congresses and has played a prominent role globally for his pioneering work in promoting the discipline of mineral processing. He is still the Editor-in-Chief of the premier minerals processing journal, Minerals Engineering, which he founded in 1988. He is also well known for the high quality MEI Conferences which he has organized annually since 1990 at various venues around the world. These conferences cover, inter alia, the areas of comminution, flotation, process mineralogy, biohydrometallurgy, etc. Besides all this Barry’s seminal text ‘Minerals Processing Technology’ is now in its 8th Edition and remains arguably the most widely used book globally for students of mineral processing. The IOM3 citation states that “Barry has served the mineral processing community immensely by promoting the distribution and dissemination of mineral processing knowledge within the community of mineral processors and extractive metallurgists worldwide” and this echoes the citation for his IMPC Distinguished Service Award.


On behalf of the International Mineral Processing Council and the global mineral processing community I wish to salute Barry for this further highly deserved recognition of his outstanding achievements and contributions to mineral processing.  Long may these continue!


Thankyou Cyril! The MEI team really does appreciate the recognition of our peers in this vital industry.

Twitter @barrywills

In memory of Philip Gray, 1927-2017

Philip Gray, a true mineral processing visionary, died two days ago, on the day that the 2017 IOM3 Awards were announced. Philip was the recipient in 2013 of the Futers Gold Medal, one of the Institute's Premier Awards. He was President of the Institute, then the IMM, in 1984-5, during which period he was elected Fellow of the Royal Academy of Engineering (FREng).
Active and perceptive right to the end, Philip was a great advocate of the Warner Process for direct smelting of sulphide ores, and was a keynote lecturer at MEI's Pyromet '07 in Falmouth. Two years ago I was honoured to interview him for MEI (posting of 2nd February 2015).
None of Philip's close relatives survive him. His wife Joan, to whom he had been married for 67 years, died only three months ago on New Year's Eve.
Philip and Joan, Christmas 2016
I am sure that many of you will have memories of Philip and I invite you to add your own appreciations to this posting.

Monday, 10 April 2017

The world's most important scientific conference takes place in Cape Town in November?

Never underestimate the importance of the mining industry. I never do, but I know that many people do, including some within our industry.
The world has an insatiable demand for metals and minerals, and the mining industry is the great feeder- without it no other industries could survive. It has become a cliché, but it is a fact that everything we touch is either mined or grown.
The massive demand for minerals has meant that the mining industry has changed enormously from the activities of the late 19th and early 20th centuries. Ores then were fairly easy to treat. In the 19th century Cornwall was the world's largest producer of copper and tin. Copper ores were of very high grade and could be concentrated for the smelter by simple hand sorting, tin ores being treated by crude gravity concentration. The increasing demand after the industrial revolution, however, meant that the 'easy' ores were becoming worked out, and the ores available were becoming more and more difficult to treat. There was an urgent need to develop a new process for concentrating these ores, as simple gravity processes were not up to the job.
The great saviour of the mining industry was froth flotation. Engineers at Broken Hill in Australia had been working on this since 1901 to enable extraction of huge quantities of zinc in the tailings dumps. It was also independently investigated by Guillaume Delprat of BHP, and Charles Potter, a brewer from Melbourne, who each patented processes to recover zinc from gravity tailings by adding acid to hot carbonate mineral slurries to generate carbon dioxide to float the minerals. Delprat's process worked succesfully at Broken Hill for many years, and there were various other attempts to use hydrophobicity, involving film flotation, which had been developed in the late 19th century, but the invention of modern flotation is attributed to Francis Elmore, who patented a vacuum flotation process in 1904, which was used in the Zinc Corporation plant for 6 years.
The first recognisably "modern" flotation technique had been patented in London in 1903 by Sulman and Picard, and this used air bubbles formed by forcing compressed air through holes in the cell, but it would be years before such pneumatic cells would be commercially used. By 1908 flotation was working well for bulk flotation of zinc tailings, but the search was then on for means of treating primary sulphides, which led to the development of xanthate collectors, selective activators and depressants, and, as they say (another cliché), "the rest is history".
Just as it is impossible to underestimate the importance of the mining industry so it is impossible to underestimate the value of froth flotation to modern society. How would we economically produce the metals and minerals that modern society cries out for without this process, which I have always referred to as the most important technological development since the discovery of smelting?
As the available ores become leaner and more complex, so flotation must continue to adapt to effectively deal with them, so research both into the physical and chemical aspects of flotation (see also posting of 6th March) continues unabated. There will be many very large scientific conferences taking place around the world this year, some with thousands of delegates, but few will be more important to society than the relatively small one which takes place in Cape Town in November- it is Flotation '17.
Flotation '17 will be the 8th in MEI's flotation series, and as always will attract the leading players in this field, researchers, equipment manufacturers, reagent companies and operators. Keynote lectures will be given by distinguished scientists, Prof. Roe-Hoan Yoon from Virginia Tech, USA (posting of 16 June 2016) and Dr. Bill Johnson from Mineralis Consultants, Australia (posting of 15th August 2016).
Current Flotation '17 sponsors
 
Intense discussions at Flotation '15
There is now a final call for abstracts. If you would like to present a paper at the conference, please submit a short abstract no later than the end of May. Papers presented at the conference will be considered for publication, after peer-review, in a special flotation issue of Minerals Engineering.
If you have any interest in flotation, you must be at the beautiful Vineyard Hotel in November! Take a look at the report on Flotation '15.
Delegates relaxing at Flotation '15

Thursday, 6 April 2017

Special issue of Minerals Engineering on Biohydrometallurgy published

 
Volume 106 (May 2017) of Minerals Engineering is now available on ScienceDirect, and contains 17 selected papers from Biohydromet '16, which was held in Falmouth, Cornwall last June, including a very interesting keynote paper from Frank Roberto of Newmont Mining, USA, on the commercial heap biooxidation of gold ores. The conference proceedings, containing all the unrefereed papers, is available on USB from MEI Online.

Biohydromet '18, MEI's 9th conference in the series, will be held in Windhoek, Namibia in June next year, back to back with Sustainable Minerals '18.

Twitter @barrywills 

Monday, 3 April 2017

Physical Separation '17- a must attend event in Falmouth in June

There is no mining operation in the world which does not make use somewhere in the flowsheet of the density difference between solids and liquids, and gravity concentration, as well as sorting, are the oldest methods of concentration.
Add to this magnetic separation and we have the ingredients for the fine technical programme for Physical Separation '17 in Falmouth, Cornwall in June.
Our six major sponsors represent all the physical separation techniques, the latest being Chinese company SLon Magnetic Separator Ltd.
Current sponsors
SLon is a leading supplier, producer, manufacturer of high gradient magnetic separators (HGMS) and wet high intensity magnetic separators (WHIMS). It designs, develops, manufactures and markets magnetic separation equipment for beneficiating weakly magnetic minerals, and for purifying non-metallic minerals. The company became a leading provider of WHIMS in China in 1980s, and from the 1990s it has become a leading world supplier of high gradient magnetic separators.
SLon has partnered with giant international company Outotec to provide innovative tailored solutions for a wide variety of customer needs in the iron and steel, aluminum and non-ferrous metals industries, and Outotec is responsible for customers in Africa, North America, South America, Europe, Russia and countries of the former Soviet Union and Australia, having five pilot-scale units available for testing around the world, as well as lab testing capabilities in the USA. Outotec USA will be represented at the conference by Riddhika Jain, who will present a paper on automation for efficient separation of the Outotec SLon VPHGMS. This machine is used for processing fine, weakly magnetic minerals, such as hematite, limonite, ilmenite, manganese, wolframite, tantalum-niobium, and etc. It is also suitable for removing iron and titanium from non-metallic minerals such as quartz, feldspar, nephline, fluorite, ceramic material, and etc.
So there is much to look forward to in Falmouth. Apart from the technical papers, there will be the presentation of the 2016 MEI Young Person's Award, an evening walk along the beautiful Cornish coast to awaiting drinks in a local hostelry, and a visit to the remains of the 19th century tin and copper mines in the Camborne-Redruth area.
MEI conference delegates exploring the old Cornish tin mines
And an added bonus- come a couple of days earlier and register for Computational Modelling '17- there are discounted rates if you attend both conferences.

Saturday, 1 April 2017

Clotted cream mining set to boost the Cornish economy

Approaching the ruins of Wheal Clott
Great news this morning of another potential Cornish mining revival. It is over 150 years since klestrolite, a mineral unique to Cornwall, was mined at Wheal Clott near Redruth.
Klestrolite is the only edible mineral to have been mined in Cornwall. It is a milky-white coloured mineral, which when ground very fine and mixed with water produces a delicate creamy paste, known as 'clotted' cream' named after Wheal Clott, the only known source of the mineral. When the mine was worked out clotted cream continued to be produced in Cornwall, but made from dairy products.
Now a rich vein of klestlorite has been found associated with quartz in hydrothermal veins in the local granite. The exact location has not been revealed but it is known to be a rich source which should boost employment in the county as well as giving locals and tourists alike the real taste of a traditional Cornish cream tea.
 
It is known that klestrolite is an anti-bacterial agent, which may be why the Cornish traditionally add cream on top of jam in their scones, and, recognising this effective barrier to foreign bodies, this has led to one of President Trump's more important executive orders.
 

Wednesday, 29 March 2017

Process Mineralogy '17 conference diary

This is a summary of events at Process Mineralogy '17, the 4th in MEI's series of process mineralogy conferences, which was held at the Vineyard Hotel, Cape Town from March 20th-22nd, 2017.
Table Mountain from the Vineyard Hotel conference centre
Monday March 20th
I opened the conference this morning, and welcomed the 97 delegates from 21 countries. The fact that numbers are higher than at the previous meeting, Process Mineralogy '14, suggest that things might be looking up in the mining industry. Over the next 3 days we have 50 presentations to look forward to, in oral and poster presentations.
I thanked our consultant, Dr. Megan Becker, of the University of Cape Town, and the companies who have provided corporate support. Zeiss, Bruker and FEI are well-known regulars, but we have two new sponsors this year. Wirsam Scientific is one of Africa's leading suppliers of laboratory instrumentation, and the Cornwall Mining Alliance connects Cornwall's unique concentration of innovative businesses, organisations and experienced professionals, some of whom are represented at the conference- MEI, Camborne School of Mines, Grinding Solutions Ltd, and conference sponsor Petrolab.
Conference Sponsors
Sustainability was the theme of the three papers leading up to the first extended coffee break. Mineral processing will have a big role to play in the push towards a circular economy, and the first keynote lecture, delivered by Eric Pirard, of the University of Liege, Belgium, showed that in order to develop efficient processes for the recovery of metals from both our primary mines and our urban mines, we will need to innovate in process mineralogy.
Eric Pirard delivers his keynote lecture
This was emphasised by Norm Lotter, of Flowsheets Metallurgical Consulting Inc., Canada (see also posting of 21 March) whose first of two papers this morning outlined the business value of best practice process mineralogy, with case studies that demonstrate the tremendous financial value that can be achieved, along with those where costly disasters could have been averted.
As highlighted by MEI consultant Megan Becker, one of nine representatives from the University of Cape Town, the development of society has been intertwined with the use of minerals over thousands of years. Our modern society is dependent on minerals and metals to sustain it. However, their provision is increasingly precarious as the minerals industry is facing multifaceted threats and challenges arising from all four pillars of sustainability: economic, technical-environmental and social. Underpinning the transformation of this industry is a sound knowledge of mineralogy - from systems level thinking to a fundamental understanding of particle behaviour. Megan discussed the key role that mineralogy plays at the various scales: from individual process units, to circuits, across the value chain (company) including waste streams, the communities surrounding them, regionally and globally. She presented a roadmap, geological as well as urban mining, that can be used to ensure provision of minerals and metals for oursustainable future.
Willem Swart, of IMP Automation, and Dieter Hoffmann of FEI, chatting
with Gaynor Yorath, of University of CapeTown, during the coffee break
Neilo Trindade, of University of São Paulo, and Cody Burcher-Jones,
of University of Cape Town, by their posters
Wirsam's Andrew Somers, Benjamin Marriam and Ian Holton
After a long coffee break in the exhibition and poster area, Norm Lotter was on the podium again, with one of his pet subjects, sampling, a key tool in modern process mineralogy, which was highlighted by Karin Engström of LKAB, Sweden, who discussed the evaluation of sampling systems in iron ore concentrating and pelletizing processes.
Karin Engström and Norm Lotter
Pekka Tanskanen
 
The morning session finished with a paper from Pekka Tanskanen of University of Oulu, Finland, who showed how on-line monitoring of spodumene flotation with novel time-resolved Raman Spectroscopy is one of the key issues for increasing profitability.
 
Automated mineralogy has been successfully used in the mining industry since the 1970s. Since that time a variety of companies have developed competing technologies with a range of capabilities, however, with one aspect in common in that they are all based on an electron beam (e-beam) system (e.g. scanning electron microscope (SEM) with energy dispersive spectrometers (EDS)). Recent technological advancements mean it is now possible to focus X-rays to a spot size of less than 20 micrometers. Accordingly, it is possible to operate a Micro-XRF system using similar parameters as an e-beam system and thus yield results compatible with automated mineralogical analysis. Sam Scheller, of Bruker Nano GmbH Germany, presented various case studies comparing the automated mineral results of the two systems, as well as discussing the various advantages and limitations of each technique. Igor Tonžetic of Sci-Ba Laboratories, South Africa, also discussed the advantages of the energing Micro-XRF technology.
Sam Scheller with delegates at the Bruker booth
Traditionally quality control in mining industries has relied on time consuming wet chemistry or the analysis of the elemental composition. The mineralogy that defines the physical properties is often monitored infrequently, if at all. Uwe König, of PANalytical B.V., The Netherlands, showed how the use of statistical techniques such as Partial Least Square Regression (PLSR) or Principal Component Analysis (PCA) on XRD raw data has been successfully trialled to determine raw materials and processed ores in addition to well established methods for mineral identification and quantification.
Uwe König (2nd left) with PANalytical colleagues Sabine Verryn and Wymand Smit (far right),
and Rob Schouwstra of University of Cape Town
With the impetus for less reliance on fossil fuels and cleaner environments, the ability to be able to economically extract lithium used in rechargeable batteries for portable electronic devices from ores is essential. However a comprehensive understanding of the deportment of lithium and associated minerals in some ore bodies is limited. Mark Aylmore of Curtin University, Australia, discussed the applications of advanced analytical and mass spectrometry techniques to the characterisation of micaceous lithium bearing ores using a Tescan integrated mineral analyser.
The final paper of the day highlighted the environmental impact of mine exploitation, Aurélie Chopard of UQAT, Canada, describing an early predictive methodology for acid mine drainage based on ore mineralogy and contaminant speciation.
Aurélie Chopard (2nd left) relaxing with delegates in the Hitachi booth
Then after an excellent first day we all headed into the beautiful gardens of the Vineyard Hotel to relax and enjoy the 'Happy Hour' (see also posting of 20th March).
 
Tuesday March 21st
Geometallurgy played a large part in this morning's session. Geometallurgy is the science of integrating geology and mineralogy with mineral processing and extraction, and is now commonly practiced but it is not yet truly embedded or “mainstream”, as discussed by Steve Williams of Pasinex Resources Ltd, Canada in his keynote lecture, in which he identified areas that geometallurgy must overcome in order to “go mainstream”.
Steve Williams (centre) with Norm Lotter and Eric Pirard
Two papers from Brazil and Norway took us up to the coffee break. Henrique Kahn of University of Sao Paulo, Brazil presented a geometallurgical study on a disseminated Ni and Cu sulfide ore, and Camilo Mena Silva of the Norwegian University of Science and Technology described a project attempting to implement the geometallurgical concept into the Norwegian mining industry, mainly dominated by industrial mineral operations.
Camilo Mena Silva (right) at the Wirsam booth
Andrew Menzies, of the Universidad Católica del Norte, Chile, said that automated mineralogy has been used successfully in the copper mining industry in northern Chile for over a decade. This has been primarily for mineral processing associated with the large Cu-porphyry mines (e.g. Escondida). However "exotic" Cu deposits are also of significant importance, but the application of automated mineralogy is complicated by the abundance of Black-Cu and Green-Cu, these “mineral groups” being difficult to classify due to their variable nature, inconsistent geochemistry and impurities, often very fine grained textures and deposition. He described how these difficulties may be overcome.
Andrew Menzies (left) at the Bruker booth
Hassan Bouzahzah

The Chelopech epithermal arsenic bearing high-sulfidation, copper-gold deposit is located in the Panagyurishte ore district in Bulgaria and is often considered as the richest European gold deposit. The processing plant treats about 2 Mt of ore per year, with an average head grade of 0.95 % Cu and 3.09 g/t of gold. Hassan Bouzahzah, of the University of Liege, Belgium, showed how a detailed knowledge of the mineralogy was vital in attaining effective copper selective flotation.
Yousef Ghorbani

The Drakelands tungsten-tin mine in Devon, UK, officially opened in September 2015 (posting of 17 September 2015), and Yousef Ghorbani, of Camborne School of Mines, UK, summarised the work to characterise the deportment of tungsten bearing minerals within the spiral concentrator circuit, the aim being to assess circuit performance and inform future processing with respect to any changes to feed mineralogy.
Industrial minerals play an important role in the Norwegian mining industry and Aleksandra Lang, of the Norwegian University of Science and Technology, showed how mineral characterization is an important tool in the implementation of geometallurgy into industrial mineral mining.
In the final paper of the morning Gerald van den Boogart, of the Helmholtz Institute Freiberg for Resource Technology, Germany, discussed the valuation of uncertainty in geometallurgical process optimisation. Geometallurgical parameters such as block models and process response models always come with a certain (geo-) statistical uncertainty. Geometallurgical optimisation often treats these model values as if they were certain, and Gerald demonstrated, with easy to understand model examples, the economic effect of ignoring the uncertainty.
The afternoon session provided an eclectic mix of papers from Germany, Zambia, UK and South Africa.
Philipp Büttner of the Helmholtz Institute Freiberg for Resource Technology, Germany described the modelling of combined processing parameters for tailing material based on Mineral Liberation Analysis data, and Sithembiso Ntlhabane, of the University of Cape Town, discussed the numerous multifaceted challenges facing the minerals industry, spanning the techno-economic, environmental and social spheres. The adoption of sustainability thinking is a holistic approach to addressing these challenges and their relative interactions, rather than just focusing on individual issues. The ability to do so requires an integrated modelling framework that incorporates mineralogy, so that the effect of ore complexity and variability on one or more of these factors can be simultaneously evaluated and optimised. Sithembiso demonstrated how an integrated modelling framework can contribute in achieving some of the sustainability principles, providing a conceptual starting point for a new approach to traditional process mineralogy studies.
Monica Kalichini
Monica Kalichini, formerly with First Quantum Minerals, Zambia, now with Bisha Mining Share Company, Eritrea, outlined the journey of setting up such a program; determining the mineralogical information most relevant to the Kansanshi processing plant, selection of the most suitable technology, installation, challenges encountered during implementation and the value of the data generated through the program to plant metallurgists and operators.
Zambia's Kansanshi Cu-Au deposit is host to a complex suite of both sulphide and oxide copper minerals. To efficiently recover copper, the process plant treats three ore types: oxide, mixed (transition) and sulphide ore. Recoveries across the process vary from 30 % copper to concentrate on the oxide flotation circuit, to 95 % on the sulphide flotation circuit. Additionally, copper is extracted through separate atmospheric and high pressure leaching hydro metallurgical circuits. The complex nature of the ore and basis of multi-stream processing makes the Kansanshi Mine an excellent candidate to generate significant value from a well-structured routine operational mineralogy program.
Ongoing developments in SEM and EDS technology present major opportunities for improvements in data quality, throughput and ease of use. As these developments are released, it is essential that users are able to quickly learn, calibrate, setup and run the systems that they are operating. Furthermore, reports must be able to be quickly generated after the completion of an automated run. Matt Hiscock, of Oxford Instruments NanoAnalysis, UK, highlighted recent improvements and developments in this field, and James Strongman, of iMin Solutions Ltd, UK, discussed the central challenge with automated mineralogy tools, of applying them in operational contexts with their often long run times, complexity and single point data sets of intricate systems. Operational mineralogy is the next stage in the development of automated mineralogy with on-site analysis, faster turnarounds and streamlined mineralogical trend analysis monitoring the health and quality of the feed and process plant. However, in order for operational mineralogy to be a viable mine-site option several factors need to be optimised, including sample preparation, sample analysis and data interpretation, and James reviewed the optimisation of sample analysis and, in particular, different case studies that it can be applied to.
Matt Hiscock with Pura Alfonso and Sarbast Hamid,
of Universitat Politècnica de Catalunya, Spain
A year ago James's company, conference sponsor Petrolab, teamed up with Australian company MinAssist to form iMin Solutions Ltd, with the aim of bringing greater mineralogical capability directly to the mine site and mineral processing plant (MEI Online). iMin Solutions is also teamed up with conference sponsor ZEISS, MinAssist working with ZEISS to provide end to end data interpretation and analytical solutions for mine sites, and Petrolab developing technology specifically for automated mineralogy based applications on the mine site and in the laboratory (posting of September 10th 2015).
And so the end of another long and rewarding day, this time with a chance to get away in the evening and enjoy dinner and entertainment at Cape Town's Lagoon Beach Hotel (see also posting of 21st March).
University of Cape Town alumni
The MEI team with Elsevier's Dean Eastbury
 
Wednesday March 22nd
It is good to have Jan Miller, of the University of Utah, USA, back with us. His travel to Cape Town was kindly funded by sponsor Zeiss. He presented a keynote lecture at Process Mineralogy '12 on the development of X-ray computed tomography, and in his keynote this morning he continued with that theme, reviewing recent advances in X-ray tomography in mineral processing, such as high speed scanning and image analysis procedures to describe particle size, shape, and composition, and the possibility for plant-site X-ray tomographic analysis.
Jan Miller (centre) with Henrique Hahn of University of Sao Paulo
and Ben Tordoff of ZEISS
X-ray computed tomography is a non-destructive analytical technique that relies on the penetration of X-rays to provide mineralogical and textural information. Implicit in this is the assumption that X-rays can effectively penetrate materials being analysed. However, X-ray penetration is a function of density and thickness, implying that the combination of mineral density and mineral proportions invariably inhibit X-ray penetration. In the second presentation of the morning Lunga Bam, of Stellenbosch University, South Africa, discussed the challenges with iron ore analysis, where the high average density of common iron minerals and the high grade of most iron ore deposits impacts the effectiveness of XCT as an analytical tool for texture and mineralogy. Lunga explored means of optimizing XCT analysis for process mineralogy applications by taking into consideration the ore grade, sample geometry and XCT system configurations.
The Hannukainen Iron-Oxide-Copper-Gold deposit is located in northern Finland and consists of the Hannukainen deposit and its northern extension, the Kuervitikko deposit. Geochemical assessment of high sulfur potentially acid-forming waste rock has included kinetic humidity cell tests (HCTs) lasting >200 weeks. The onset of acid generation exhibits a considerable lag time which is hypothesized to be caused by the coarse crystallinity of sulfide minerals and a subsequent low oxidation rate. In order to understand the relative importance of the textural controls on acid generation, Chris Brough, of Petrolab Ltd, UK, showed how pre-leach HCT material was subjected to quantitative 2D Zeiss Mineralogic and 3D micro-CT liberation analysis. The results assess the stereological bias of 2D liberation analysis in HCTs along with the pyrite-pyrrhotite distinction in micro-CT analysis.
Chris Brough and James Strongman, of Petrolab,
with Alan Butcher of Geological Survey of Finland
After the coffee break Kate Tungpalan, of the University of the Philippines, discussed the role of vein-type mineralisation in mineral liberation, and Pierre-Henri Koch, of Luleå University of Technology, Sweden, showed that in geometallurgy a process model operating at the mineral liberation level needs quantitative textural information from the ore, the use of this information for process modeling and simulation increasing the quality of the predictions.
Kate Tungpalan and Pierre-Henri Koch
Sarbast Hamid
Sarbast Hamid, of the Universitat Politècnica de Catalunya Barcelona Tech, Spain, gave an overview of the modelling of the liberation of scheelite, and Eetu-Pekka Heikkinen, of the University of Oulu, Finland, described a mineralogical study to determine agglomeration free heat treatment conditions for spodumene concentrate.
In the final paper of the morning, University of Cape Town's Theo Dzingai discussed the effect of phyllosilicates in the processing of Zimbabwe's Great Dyke PGE ores, showing the relative contribution of the different phyllosilicate minerals to processing challenges, and the potential opportunities to manage them.
And so on to the final session of the conference, with the first paper of the afternoon presented by Abraham Rozendaal, of Stellenbosch University, South Africa, who discussed grade and product quality control by micro-CT scanning of the Namakwa Sands Ti-Zr placer deposit West Coast, South Africa. The Namakwa Sands operation is a world class producer of zircon, rutile and ilmenite from mainly unconsolidated marine and dune sands. The high density contrast between the economic minerals, as well as the diverse gangue mineralogy, allows the use of micro-CT Scanning as a tool to, for example, quantify zircon grain size, concentration and intergrowths in the primary ore, intermediate stages of the separation process and purity of final saleable product.
Abraham Rozendaal (left) at the ZEISS booth
Marius Kern, of Helmholtz Institute Freiberg for Resource Technology, Germany, described the development of a method to determine the deportment of major elements and Sn of a mineralogically complex and fine-grained skarn ore, using Mineral Liberation Analysis (MLA) and electron probe microanalysis. The method allows the quantification of Sn mineral abundances and their Sn contents and qualifies for monitoring future processing experiments and production control. Similar approaches may well be considered for other mineralogically complex ores containing a multitude of ore minerals.
Two papers dealt with rare earth element (REE) treatment. Mohamed Edahbi, of UQAT, Canada, discussed a mineralogical and geochemical study of REE from the Montviel carbonatite deposit in Quebec and Desh Chetty, of Mintek, South Africa, presented results of mineralogical studies to develop a novel approach for the extraction of rare earth elements from ferruginised REE ores.
Mohamed Edahbi and Desh Chetty
Finally two papers from the University of Tasmania, originally scheduled for Monday, but husband and wife Nathan Fox and Anita Parbhakar-Fox were severely delayed on their long flights from Tasmania, via Melbourne, Singapore and Johannesburg. Nathan described the use of microanalytical techniques for characterising critical metal deportment in mine materials, and Anita discussed improved mine-waste characterisation through blended testwork.
Nathan and Anita with Mark Aylmore (left)
MEI's process mineralogy consultant, Megan Becker, then summarised the meeting, and presented Kate Tungpalan and Pierre-Henri Koch with copies of the new volume Process Mineralogy (posting of 22nd March) for best student presentations.
Kate and Pierre-Henri with book authors Megan Becker,
Elaine Wightman and Cathy Evans
MEI's Amanda Wills closed the conference, thanking the sponsors, chairmen, authors and delegates, and made the first annoucement for Process Mineralogy '18, which will be held in November next year in a completely new venue and country, Cancun in Mexico. There will be more news of this on MEI Online soon.
Finally we adjourned into the Vineyard Gardens again for a farewell wine reception See also posting of 22nd March).
As in previous years, this has been a most rewarding event, and it is still ongoing- all the authors have been invited to submit final papers to Minerals Engineering journal for peer-review, and those accepted will be published in a special issue of the journal early next year. The draft papers from the conference are available from MEI Online.
Twitter @barrywills