Salt-tolerant bacteria could end need for copper mine desalination
Researchers at Australia's national science agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) claim to have found a means to end the need for desalinated water in a major copper mining process.The scientists have discovered a bacterium that can tolerate high salinity and acidic conditions which could be used to leach copper minerals from ore - a process that currently requires high volumes of fresh water. Some 5% of copper mined worldwide is mined using bacterial leaching from low-grade ore
CSIRO environmental microbiologist, Suzy Rea, said fresh water was a major cost item in the mining industry. "In Chile, the biggest copper mine in the world is right next to the sea. So if we have found bacteria that can manage salty water, then they wouldn't have to either build desalination plants or transport water in, and that would save a lot of money and be useful environmentally too," she said.
The salt-and-acid-tolerant bacteria was found in drains on farmland near Merredin and Beacon in Western Australia. It has yet to be shown to be capable of bioleaching copper but Rea said the bacteria had already been shown to withstand high sulphate concentrations - a prerequisite for the leaching process which is based on oxidation of sulphides to sulphates.