Bangor’s expertise in ‘world-changing’ technology
The Escondida mine in the Atacama desert, Chile; currently the largest copper mine in the world. An area of research in which Bangor University is a world leader, is described by this month’s (December) issue of Scientific American as one of ten ‘world-changing ideas’.
The technology is known as “biomining”, and in it bacteria and other microorganisms are harnessed to extract valuable metals, such as copper, nickel and gold, from ores. This approach allows mining companies to extract metals from materials that contain metals that are difficult to process using conventional methods (most roasting the ores in smelters) or contain so little metal that they are otherwise too expensive to work with, and so are discarded as waste rocks. Biomining bacteria also have the advantage that they can be used to clean up pollution caused by earlier mining activities and, in some situations, extract more valuable metals from old mine wastes.
Biomining is regarded as a “green technology” that will become even more important in future years, as it avoids much of the energy costs and carbon footprint associated with conventional mining. Although extracting metals using bacteria is much slower than roasting ores, the bacteria “work for nothing” as they actually use the energy present in the minerals themselves. As an added bonus, they take carbon dioxide from the air (like green plants) and therefore help to counter the problem that is acknowledged to be behind climate change.
Professor Barrie Johnson of Bangor University’s School of Biological Sciences is a world leader in this field and is quoted in the article.
Copper rich pools (produced by bacteria) at the Bingham copper mine in Utah, which boasts the biggest man-made hole in the world (viewable from the space station).Recently, he has been working with two of the world’s largest mining companies to devise new strategies for extracting metals from vast ore deposits in Australia and South America that were not previously thought to be amenable to biomining. He is also working with new biological systems that can not only treat polluting waters that drain from abandoned mines, but can also recover metals from these waters in a form that allows them to be recycled. This particular technology is in its early days, and it might take 20 years or more to see its widespread application. But in a world that is demanding more and more metals from dwindling global resources, using biological solutions to extract and recover metals is becoming increasingly attractive.
Professor Johnson said: “As the world moves on to a less carbon-dependant society, we have to look for ways of doing things that are less energy-demanding and more natural. That’s the long-term objective of harnessing microbes for the mining process, and things are starting to move nicely in that direction.”
Professor Johnson works with scientists and industrialists in many part of the world, including North and South America, Asia, Africa and Europe, and has acted as an advisor on biomining to the International Atomic Energy Agency. Many of the bacteria used in the processes he develops have been isolated from volcanic and geothermal areas, such as the Caribbean island of Montserrat and Yellowstone National Park as well as old mine sites, including Mynydd Parys (Anglesey).
A paper by Prof Johnson and colleagues including Kevin Hallberg of Bangor University has been awarded the Hatch Annual Awards for Excellence Best Technical Paper Award. Hatch is an employee-owned, multidisciplinary professional services firm that supplies engineering, project and construction management services, process and business consulting and operational services to the mining, metallurgical, energy and infrastructure industries.
Publication date: 16 December 2011