WA Mining’s salty little helpers

Salt-tolerant bacteria that can break down rocks could replace smelters and chemical plants in the extraction of heavy metals from ores in Western Australia, thanks to new research.

Carla Zammit, a scientist at the Parker Cooperative Research Centre for Integrated Hydrometallurgy Solutions, has identified microorganisms that look promising for use in “biomining” in the state.

She will tell the Pathfinders 2010: Challenge and Change Conference at the Alice Springs Convention Centre this week (May 26–28) that biomining has big advantages over traditional ore extraction techniques. “It has lower set-up, operational and maintenance costs, zero smelter emissions, and the microorganisms used absorb atmospheric carbon dioxide,” Miss Zammit said.

About 20 per cent of the world’s copper production comes from biomining. But the technology has been limited in Western Australia because the commercially-available microorganisms currently used cannot tolerate the state’s salty soils and water. “Biomining is used at only two mines in the state,” she said.

Her quest for suitable Australian microorganisms took in 16 sites in the acidic and saline lakes and drains of Western Australia’s wheatbelt “These environments provided the perfect conditions for the growth of the elusive salt tolerant biomining microorganisms,” she said.

One “extremophile” was chosen for detailed examination because of its superior ability to break down iron, a trait used to gauge microorganisms’ biomining potential. Miss Zammit tested the sample for growth speed and ability to attack iron ores in different salinity levels. “The microorganisms tolerated salt at the same concentrations as seawater,” she said. Further research is under way on the organism, and the CRC, which includes the CSIRO and Curtin University of Technology, has attracted interest in the technique from the mining industry.

Miss Zammit is one of eight early career scientists invited to present their research results at the Pathfinders Conference, organised by the Cooperative Research Centres Association. The CRCA represents Australia’s 50 CRCs operating under a federal government program to drive public/private sector research.

See the conference program at http://crca.asn.au/conference

See the media releases at http://crca.asn.au/media/annual-conference


Carla Zammit Ph: 0434 894 040 Email: [email protected] or [email protected]

Laurelle Halford (Alice Springs Convention Centre, May 26–28)

Ph: 0417 222 211 Email: [email protected]

CRCA Media Ph: 0419 250 815 Email: [email protected]