Biomining ’21 Day 1

Monday June 7th

It is now three years since MEI’s last biomining conference, Biohydromet ’18, in Namibia. Biomining ’20 was originally scheduled to be held in Falmouth last year, but was postponed for a year, and due to the ongoing pandemic became an online event.

Biomining ’21, the 10th in the series, is sponsored by AFX Mixing & Pumping Technologies & Newmont. Media sponsor is International Mining and Industry Associates are the Cornwall Mining Alliance, Ocean Mining Intel and the Critical Minerals Association.

Although there is evidence that bioleaching was used in the Rio Tinto area in Spain prior to Roman occupation, for the recovery of copper, as well as in China some 2000 years ago, it is only over the past 40 years that biohydrometallurgy has been increasingly recognised as a niche technology for extraction of metal values from refractory and low grade ores, often used as an avenue of last resort on ores that are untreatable with other methods. 

It is a complex technology, needing fundamental understanding of microbiology, engineering, mineralogy, hydrometallurgy etc. and it has a relatively low number of global researchers compared with flotation for instance. The Namibia conference was attended by around 50 delegates, and this year we have over 70 delegates from 20 countries attending from the comfort of their own home or office, and it is the 2nd highest attendance in the series.

Processes based on biohydrometallurgy have the potential to enhance the degree of extraction from the overall resource and this has led to the development of commercial tank and heap bioleaching processes to recover base metals, particularly copper, and biooxidation to enable subsequent recovery of gold and PGMs.  Some say that biotechnology can deliver environmental benefits over competing extraction approaches, but Prof Barrie Johnson questioned in his keynote lecture this morning whether such 'green' claims stand up to close scrutiny.

Currently, the recognition of the relevance of biohydrometallurgy in a broader context is growing. With the increasing emphasis on the need to develop a circular economy, biotechnology has the potential to expand the range of technologies needed to process secondary resources, such as old tailings deposits and municipal waste, and to help in the recycling of metals from waste electrical and electronic equipment,

New challenges for biohydrometallurgists include accounting 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.  

All these aspects of biomining will be discussed over the next few days, culminating in a final day panel discussion asking what is the future of biomining.

Jon Wills opens the conference from Falmouth

MEI’s Jon Wills opened the conference this morning, welcoming all our delegates, after which Prof Barrie Johnson delivered his keynote “How green was my biomining?”; a personal critique of the limitations and untapped potential of applying bioprocessing techniques for metal extraction and recovery”.

Barrie, a Professor at Bangor and Coventry Universities, UK, also has honorary chairs at the University of Exeter and Central South University, China, and has vast experience in biohydrometallurgy. His presentation gave 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 also highlighted where new developments, currently at the laboratory or pilot-scale stage of development, could have major environmental impact in future years.

Cambridge 2015: Barrie Johnson with Anita Parbhakar-Fox,
a keynote lecturer at Sustainable Minerals ’21 in two weeks time 

The keynote was followed by a very full day of 13 presentations on the bioleaching of ores and concentrates.  The abstracts are available on the conference website, and all the presentations, and associated discussions, are available on demand until the end of the year, so registration is still open.

#Biomining21