Mining a narrow vein of research

University of Queensland research is helping to make narrow-vein mines more efficient.

When people think of mines they usually picture the massive open cut mines of Mt Isa and Western Australia, but Dr Penny Stewart found the world of narrow underground mining more to her liking as part of her PhD research.

“The problem with narrow-vein mines is that there is usually a lot of extra material (dilution) handled that is not needed,” Dr Stewart said.

“This is due to a lack of precision when mining, taking too much out in an effort to get the vein of gold.

“High dilution reduces the profitability of an operation as it increases costs and results in poor use of resources.

“In the case of a typical 500,000 tonne per annum narrow-vein mine, over mining a 0.4 metre wide vein by 0.25 metres would cost approximately $6.25 million in direct operating costs alone.

“The narrower an orebody, the more exposed it is to the risks associated with achieving precision in mining and inaccurate dilution prediction.”

Dr Stewart approached the problem by proposing a more accurate methodology that combines geotechnical, blasting and equipment elements.

“While finishing my PhD part-time I worked for AMC Consultants and applied these finding and methodologies at two Queensland mines – the results were encouraging,” she said.

“I have established benchmarks for dilution prediction and minimization in narrow-vein mines.

“This represents a significant improvement in dilution prediction accuracy and I hope within time it will become an industry standard.”

The former UQ mining engineer graduate, who spent five years working in WA and Tasmanian mines, said her research was already garnering interest overseas.

Dr Stewart undertook her PhD studies at UQ's Julius Kruttschnitt Minerals Research Centre, under the supervision of Dr Robert Trueman and Dr Gideon Chitombo.

She continues her research while operating a contract research and consulting business Sigma Services based in Orange, NSW.

Media inquiries: Dr Penny Stewart (0400 585 177 or 02 6360 1715) or Andrew Dunne at UQ Communications (07 3365 2802 or 0433 364 181).