Tuesday, 19 June 2018

Weekend in the Namib Desert

I am pleased that many of the delegates at last week's MEI conferences in Windhoek chose to stay on to explore the incredible natural attractions of Namibia, and I hope that some will share their experiences in the next week or so.
Namibia is a vast country and visitors must expect to travel great distances to see its splendid sights (see also Exploring Namibia- posting of 26 April 2014). Barbara and I returned to Windhoek yesterday after spending a couple of nights at the Namib Desert Lodge, a 4 hour drive from Windhoek. 
After a very early morning rise on Sunday our guide drove us into the Namib National Park and along the Tsauchab dry riverbed, which passes through the impressive dunes until it reaches the Sossusvlei clay pan, from where we walked to the awesome Dead Vlei, where 900 year old dead acacia tress stretch their branches into the blue sky.

Tsauchab river bed
Dune 45, the highest in the area
Climbing Dune 45
Dead Vlei
Returning to the Lodge we walked to the bottom of the Sesriem Canyon, which was cut into the 15 million year old sediments of sand and gravel agglomerates by the Tsauchab River.
Sesriem Canyon
And then back to the Lodge for a short rest before a late afternoon sundowner, passing through some stunning scenery and culminating with gin and tonics by the light of the setting sun. A fitting end to our 10 days in this friendliest of African countries.
Namibia's national animal, the oryx
Twitter @barrywills

Saturday, 16 June 2018

The sun sets on a fine week of conferences in Namibia

Sustainable Minerals '18 finished yesterday afternoon, with a final sundowner by the pool at our wonderful new venue, the Windhoek Country Club.

Namibia in June proved to be a good choice, with its relatively mild winter temperatures. At 1655 metres altitude Windhoek is the world's 12th highest capital city, and mid-day temperatures reached a pleasant 25C, plummeting fast after sunset to as low as 2C.
Many of the delegates are taking the opportunity of exploring this beautiful African country, and we invite you to submit photos of your adventures to us for possible publication on the blog.
I will be publishing full reports on Biohydromet '18 and Sustainable Minerals '18 during week beginning June 25th.
The next MEI events are in Cape Town in November. Hi-Tech Metals '18 follows Process Mineralogy '18 at the Vineyard Hotel. If you would like to present papers at either of these two events, please send your abstracts as soon as possible, as we will be assessing submissions later this month (more details on the posting of 3rd May).
Twitter @barrywills

Friday, 15 June 2018

The importance of mineral processing in the quest for a circular economy

Sustainable Minerals '18 has the tag “Towards a circular economy”, and in opening the conference this morning, after thanking our corporate sponsors Outotec and Zeiss, I spoke about the crucial role that mineral processing and extractive metallurgy will have in this quest. 
With a world population of 7.6 billion, sustaining our way of life is becoming a major issue, but it is not widely acknowledged that a sustainable society is very much dependent on a sustainable mining industry. The perception with many is that the mining industry is a dangerous, dirty business run by capitalists intent only on self-gain at the expense of the environment. The reality is that society could not exist without a thriving mining industry; it is the great feeder which allows all other industries to operate.
Mining never gets easier, the tonnages mined steadily increase while the available ores become ever leaner and complex, so in order for the industry to be sustainable it must continually adapt to these changes and innovate.
No better example of the need to innovate can be found than by looking at the state of the industry at the beginning of last century, when increasing industrialisation had led to a rapid rise in the demand for metals, particularly the base metals such as copper. The widespread use of electricity at the end of the 19th century vastly inflated the demand for the red metal and the high grade ores, of which Cornwall had been the biggest supplier, soon became depleted. Attention then turned to the vast quantities of low grade base metal ores in Australia and the Americas. 
However, as the only option for recovering the metals from these ores was smelting, it was necessary to upgrade them for economic extraction, and the only methods available were hand sorting and simple gravity concentration processes, totally inadequate on these low grade finely disseminated deposits.
The mining industry was in a crisis, and so was the new industrialised world which was reliant on these metals. The search was on for a means of concentrating these ores, and the saviour of the industry was froth flotation, often described as the most important technological development since the discovery of smelting.
Froth flotation is now the mainstay of the mining industry, and there are few mines in the world which do not use it somewhere in the flowsheet. It is true to say that without it the base metals would be regarded as precious metals, and we would live in a very different civilisation.
One metal which we now take for granted, and was indeed a precious metal in the late 19th century, is aluminium, which was more precious than gold although it was well known that it had potential as a light, strong metal which would not corrode, due to its passive oxide layer. No one of sound mind would have predicted that aluminium would one day be a cheap metal in global use for common household utensils, the invention of the Bayer and Hall-Héroult processes allowing the economic mass processing of bauxite ores. At around the same time cyanidation of gold ores was invented, these processes marking the birth of modern hydrometallurgy, which has seen many innovations in the 20th Century, with the continuing development of leaching and bioleaching, solvent extraction and ion-exchange.
A century later what are the big challenges now facing the industry in order to sustain ever increasing demand for metals and minerals, which will be influenced in a major way by the electric vehicle revolution? There will be a massive boom in metal mining as electric replaces the internal combustion engine, and copper, nickel, lithium and cobalt should particularly benefit (as well as non-metals such as graphite). According to Glencore, a typical electric car would need about 160kg of copper, 11kg of cobalt and 11kg of nickel.
It must be remembered that ores are finite resources, so there will be an increasing strain on primary sources, and a concomitant increase in energy and water requirements. Critical to a sustainable future, however, is the need to move from a linear to a circular economy, by retreating old tailings dumps and crucially by recycling materials at the end of their effective lives.
Recycling is viewed by many as the panacea of sustainability. Once an article has reached the end of its useful life, you take it to a municipal waste centre, and it is recycled for further use. This is fine for products made from a single material such as glass, which can be melted down and reused, or for certain metals which are used in their native form, such as copper and lead. However when metals are alloyed with other metals or non-metals, recycling becomes much more challenging and if the metals and other elements are in tiny amounts in a device, then the problem becomes even more complex. Perhaps the greatest recycling challenge is that of recovering metals from waste electrical and electronic equipment (WEEE) and other complex high-tech products. Some of these metals, such as germanium and gallium, are dependent on their primary production on base metal mining, from which they are by-products. Indium, now critical to our modern lifestyle, is the most important ingredient, as an indium-tin oxide, in the production of ubiquitous touch screens. Indium is produced in small amounts from the mining of Zn ores, and the sheer number of smart phones, tablets etc. produced each year requires around 700 tonnes per year of indium. Recent estimates however, suggest that total reserves are around 16,000 tonnes, so it is a very finite resource, and great efforts are being made to recycle it.
So there are great challenges ahead and mineral processing will be at the forefront of the future quest for a circular economy, which is why this conference series is so important, not only to the mining industry, but to society in general.
My opening remarks preceded a full day of 14 presentations, beginning with Rob Dunne's keynote "Water- crisis, conflict, resolution?".
And at the end of a long day, what better way to relax than with drinks at the evening sundowner overlooking the Country Club's impressive golf course.
Twitter @barrywills

Thursday, 14 June 2018

Into the township for a taste of Africa

Biohydromet '18 ended yesterday afternoon, and during the final session delegates began to register for Sustainable Minerals '18.
The two groups joined in the evening for a memorable evening at the Xwama Cultural Village, in the heart of Katutura, Windhoek's most diverse and vibrant township.
A great evening of African entertainment and food in a truly atmospheric setting.

Twitter @barrywills

Wednesday, 13 June 2018

Chilling out after a long first day at Biohydromet '18

The first day at Biohydromet '18 was long and intense, but memorable for its great presentations, initiated by Sue Harrison's very topical keynote (posting of 11th June).
The Windhoek Country Club is a brand new MEI venue, so we have been a little nervous about it over the past few weeks, but we needn't have been, as it surpassed all expectations, with its excellent conference facilities and quite superb catering.
At the end of yesterday's technical sessions we had the first of our sundowners poolside, and it was great to mingle with the friendly and interesting people in the world of biohydrometallurgy as the sun set on a cool and crisp African day.
Twitter @barrywills

Tuesday, 12 June 2018

Namibia 2018 off to a good start

MEI’s Jon Wills opened Biohydromet '18 this morning, welcoming the 52 delegates from 12 countries to the Windhoek Country Club, and thanking Outotec for their corporate support. Many of the delegates we met yesterday at the late afternoon welcoming reception.
This week is MEI’s first outing in Namibia and we are pleased to be associated with the relatively newly formed Namibia University of Technology. Following Jon’s opening remarks, the Vice-Chancellor of the University Prof. Tjama Tjivikua gave his own words of welcome to this friendliest of African countries.
Of the 52 delegates, 32 will be staying on for Sustainable Minerals ’18 which begins on Thursday, the two conferences having a common informal dinner tomorrow evening.
Appropriately the first presentation of the day was a keynote lecture by one of our conference consultants, Prof. Sue Harrison, of the University of Cape Town, who talked about the role of biohydrometallurgy in the sustainable development of mineral resources. 
Sue, Jon and Tjama
Over the past 40 years, biohydrometallurgy has been recognised increasingly as an emerging technology for extraction of metal values from recalcitrant minerals, low grade ores or mineral resources carrying penalty metals.  This has led to the development of commercial tank and heap leaching processes, processing concentrates and crushed ores to liberate metals of interest through bioleaching of base metals and biooxidation to enable subsequent recovery of gold and PGMs.  The potential of in situ leaching of mineral reserves is under consideration with biohydrometallurgy of key interest owing to the potential for ongoing regeneration of leach agents.  
Processes based on biohydrometallurgy have potential to deliver environmental benefits over competing extraction approaches and to enhance the degree of extraction from the overall resource. While many of the commercial applications of biohydrometallurgy for recovery of metal values use solvent extraction and electrowinning for metal recovery, the importance of biohydrometallurgy in the recovery of metals or, mainly, the removal of metals from aqueous solutions has been considered from the environmental perspective through, for example, biological sulfate reduction with associated metal precipitation.  
Currently, the recognition of the relevance of biohydrometallurgy in a broader context is growing.  Key aspects include the need to account for unintentional bioleaching reactions on the disposal of waste rock and tailings and the need for the long term prevention of such reactions to enable appropriate handling of waste rock and restoration and rehabilitation of prior mine sites with associated protection of water resources.  Further, limited global resources of key metals highlight both the need to process mineral resources of decreasing grade, smaller size of deposit and increasing complexity and the ability to extract metals from secondary sources for re-use.  In the former, biohydrometallurgy has potential to expand technological approaches.  In the latter, with an increasing focus on the circular economy, the sources of metals or modern-day ‘ores’ are changing to include secondary resources such as waste electrical and electronic equipment (WEEE) and municipal solid waste (MSW). These present new challenges for biohydrometallurgists.  
Sue’s presentation provided the ideal start to a day of papers dealing with innovative bioleaching of low grade compex ores, such as copper, zinc, nickel laterites, rare earths and and precious metal ores.
Twitter @barrywills