Probe to make mine waste safer

A network of small oxygen probes could avert acid damage to the environment and save mining companies millions of dollars.

The CSIRO developed probe is poised to revolutionise the way mining companies monitor the rehabilitation of Australia's mine sites, especially where acidic mine wastes are present.

The presence of oxygen in sulphidic mine wastes results in oxidation of the sulphide minerals, and with water forms sulphuric acid. The resultant acid mine drainage causes contamination of surface and groundwater. To reduce or eliminate this contamination, the mineral wastes are commonly covered with earth or synthetic covers.

The CSIRO probe has successfully provided a detailed and accurate assessment of the long-term stability and effectiveness of these covers to prevent oxygen reaching the mineral wastes.

The instrument achieves this by accurately, cheaply and continually monitoring oxygen levels in mine waste sealed under the covers.

Potential contamination from mine sites is a large environmental liability for the mining industry.

"Acid mine drainage caused by the oxidation of sulphidic mining waste is one of the biggest environmental problems faced by the mining industry," says Dr Brad Patterson, an environmental chemist with CSIRO Land and Water who has worked on the probes for over 5 years.

"Currently, managing these wastes costs the Australian mining industry around $60 million a year," he says.

Despite concerns about the long-term effectiveness of the earth coverings, this method is, at present, one of the few cost-effective solutions to preventing acid leaching from the mine waste into the environment.

For further information contact Dr Brad Patterson, CSIRO Land and Water on 08 9333 6276 or Dr Graham Taylor CSIRO Land and Water on 08 8303 8437.

Item provided courtesy of CSIRO