Thursday, 8 April 2021

How green is bioprocessing?

The modern era of biomining began in the 1960s, with low-tech “dump leaching” used to recover copper from what had been considered to be waste (run-of-mine) rock. “Biomining” has since evolved into a variety of more complex engineered practices, including bioheap leaching and stirred tank operations. 

Protagonists, and particularly researchers justifying support from industry and research councils, have often promulgated the notion that bio-processing is a much “greener” method of winning metals than conventional (e.g. pyrometallurgy and pressure leaching) approaches. But according to Prof. Barrie Johnson, of Bangor University, UK, such claims do not always stand up to close scrutiny. 

In his forthcoming keynote lecture “How green was my biomining?”; a personal critique of the of the limitations and untapped potential of applying bioprocessing techniques for metal extraction and recovery", at Biomining '21 in June, Barrie will give a critical overview of the environmental impact of biotechnologies in mineral processing and metal recovery, identifying areas where existing approaches have (and do not have) significant green credentials, and will also highlight where new developments, currently at the laboratory or pilot-scale stage of development, could have major environmental impact in future years.

Barrie Johnson with Bangor University colleagues at Biohydromet '16 in Falmouth

Biomining '21 will be MEI's 10th International Symposium on Biomining,the postponed Biomining '20, which was scheduled to be held in Falmouth.

#Biomining21

Monday, 5 April 2021

Comminution '21: only two weeks away, and two new sponsors

MEI's first online conference begins two weeks today. Comminution '21 is our 12th comminution conference, and I must say that I am excited about attending as a delegate, along with the other delegates, while Jon and Amanda do the hard work of ensuring that the proceedings move smoothly.

We also welcome two late sponsors, Dakot and Cancha, who join our existing sponsors and we look forward to networking with them during the event.

South African company Dakot are sponsoring an MEI comminution conference for the 3rd time. 

Dakot was established in 1995 to manufacture high-tech ceramics for specialised applications. In 2007 it diversified into the production of ceramic micro-milling media. The company has positioned itself as one of the world leaders in the large scale production of toughened alumina and zirconia grinding media for stirred mills, which will be featured in the final morning session of the conference.

Cobus Kotze (2nd left) of Dakot, with Aubrey Mainza and Paul Bepswa, of UCT,
and Magnus Evertsson of Chalmers University, at Comminution '18

Peruvian company Cancha is a first time MEI sponsor. Cancha is used by geologists, miners, metallurgists and geometallurgists to accurately, efficiently and transparently project metallurgical performance for mineral resources, the geometallurgy software bridging the gap between orebody knowledge and comminution simulators. 

Cancha's Transmin offers professional metallurgical consulting services to the mining and mineral exploration industries and I first met consultant Adam Johnston at the SME Annual Meeting in Denver in 2019. 

With Adam Johnston, and Stuart Smith of Metifex, Australia in Denver in 2019

Adam says that he is "happy to be able to support this conference.  For many years we have enjoyed reading the papers from the Comminution conferences in Minerals Engineering, but travel and time has always been a barrier to get there in person.  Now with it being online, and us being locked-up, we are able to get involved".

It is good to have these two late sponsors involved, and I hope that others, who have been unable to travel to our conferences for whatever reason, will avail themselves of the opportunity of registering and networking with comminution experts from around the world, in the comfort of their own homes or offices.

#Comminution21

Thursday, 1 April 2021

March update: Coronavirus, University rankings, UK mining news and a levitating ship in Falmouth Bay

Champagne corks were flying throughout the land on the 8th of the month, as many parents, Amanda and Jon included, celebrated the return of their children to school. The nation is still effectively in lockdown, but the tide seems to be turning in the UK and restrictions were eased on the 29th. However, with a resurgence of infections in Europe, Boris Johnson warned that the effects of a third wave of Coronavirus in Europe will "wash up on our shores" and that we should be under no illusion that the country will feel the effect of increasing European cases. March 23rd was the first anniversary of the initial lockdown, and since then the UK's official death toll rose from 364 to 126,172 twelve months later.

The roll out of the Coronavirus vaccines has been impressive to say the least. At the end of the month  31 million people in UK had received their first jabs and over 4 million their second. The NHS must once again be highly commended for this. Front line workers have put their lives on the line throughout the pandemic and over 150 nurses died, so it was not surprising that there was an inevitable backlash to the Government's offer of a 1% pay rise, presumably to supplement the appreciation received by clapping during the early months of lockdown, and ministers saying that their gratitude was incalculable.

Chancellor Rishi Sunak and PM Boris Johnson
clap for front-line health workers outside No. 10

This meagre offer coincided with a report from the House of Commons Public Accounts Committee showing that there was no clear evidence that the "unimaginable" budget of £37 billion for the NHS Test and Trace system had been justified and had made no measurable difference to the progress of the pandemic. In early February it was still employing around 2500 consultants at an average daily rate of £1000 with some paid £6624 per day, putting the pay rise to nurses, of around £3.50 per week, into perspective.

In other news the 2021 QS World University Rankings were published last month, and in the field of Minerals & Mining Engineering, the Camborne School of Mines had its highest ranking ever, number 8 in the world (as University of Exeter).  All the more ironic as in January, following 5 months of deliberations, Exeter University decided to continue the ‘pause’ in offering the Mining Engineering undergraduate degree programme, effectively bringing an end to CSM's proud record of training graduate mining engineers, which has its origins back to 1888, and all at a time when there is a resurgence in mining activity in Cornwall.

Cornwall has always been regarded as the birthplace of modern mining, once being the world's largest producer of copper and tin. Now of course there is also lithium, and there was good news last month that British Lithium Ltd has been awarded a grant of almost £3m by the government’s Sustainable Innovation Fund, which will allow the company to progress its plans for a pilot plant to prove the sustainability and commercial benefits of its Li-Sep technology for extracting battery-grade lithium from micaceous granite in east Cornwall. 

Progress also continues in bringing one of the county's oldest tin mines into production again. In 1998 South Crofty was the last of Cornwall's tin mines to close, and its redevelopment by Cornish Metals involves the formidable task of dewatering the miles of ancient underground workings. Extensive pilot-scale water treatment trials have been carried out and the company has successfully applied for and received the necessary environmental permits to abstract, treat and discharge mine water in order to dewater the mine.

There was good news in March that an agreement had been reached with Wheal Jane Ltd for the disposal of waste material derived from the treatment of mine water from South Crofty into the Wheal Jane tailings dam located 12 kilometres east of South Crofty at Baldhu near Truro.  In addition to that the company has also made a deal to lease a 1.2 hectare site surrounding New Roskear Shaft in Camborne for up to 23 years, together with an agreement to lease the mineral rights owned by Roskear Minerals LLP within the South Crofty Underground Permission Area for up to 25 years. 

In 1920, when further exploration of the bottom levels of Dolcoath Mine (posting of 3rd August 2015) became unprofitable, the mine was abandoned and attention was directed to the Roskear section to the north and in 1926, New Roskear, a 650 metre deep, six metre diameter shaft in the centre of Camborne was sunk to a depth of 2,000 feet between the North and South Roskear main lodes, in order to explore the ground below the copper ore zone of these mines where rich tin ores were believed to exist. During the 1980s and 1990s, much of the ore mined from South Crofty came from this part of the mine, and the new agreement secures access to the shaft, which is important for ventilation and access to South Crofty.

The capped New Roskear shaft

Not so good news in the north-west of England, however, where a public inquiry has been announced into plans for the Cumbria coal mine (posting of 14 January) after another of the government's famous U-turns. Green campaigners say the mine will increase carbon emissions and send the wrong signal in the run-up to a UK-hosted climate conference in October. Asked whether the government now backed the mine or not, Boris Johnson said he couldn't get involved as it was now a "qausi-judicial planning decision" (a shame he didn't read my posting on clear technical English).

The Conservative MP for nearby Workington, Mark Jenkinson, called the decision a "capitulation to climate alarmists". He said the "screeching U-turn" could open a "Pandora's box" over how the UK's contribution to climate change is measured, adding there was "nothing on the horizon" to replace coking coal in the process for making steel, a sector that is due to play an important role in the UK's "green recovery".  As I said in my posting of 14 January, it may seem paradoxical, but mining of coal is essential in the quest for a zero-carbon society. Metallurgical coal, which would be mined in Cumbria, is required to produce steel, but it is rarely appreciated that fossil fuels, whether from coal or gas, will also be needed for some time yet, in order to help build the electric vehicles and wind turbines of the future. There just aren't enough renewable sources of energy at present to provide the energy to mine and extract the necessary raw materials and to manufacture the multitude of renewable energy devices and electric vehicles which are proposed.

The government could still decide to approve the mine, but given the amount of anger it's caused, that seems unlikely - at least until after the UN climate conference.

And finally, on a lighter note, earlier in the month, a hovering ship was seen off the Falmouth coast, the result of a rare optical illusion known as a "superior mirage" where special atmospheric conditions bend light. Superior mirages occur because of a temperature inversion, where cold air lies close to the sea with warmer air above it. Since cold air is denser than warm air, it bends light towards the eyes of someone standing on the ground or on the coast, changing how a distant object appears, the opposite of an "inferior mirage" where the light is bent the other way, and the mirage image appears below the true object, as in desert mirages.

@barrywills