CSIRO develops new X-ray technique to uncover gold

The CSIRO has created a new technique that uses powerful x-rays to detect gold in ore samples.

Developed with Canadian company Mevex, the gamma-activation analysis' (GAA) recent pilot study demonstrated the technology providing a faster, more accurate way to detect gold than traditional chemical analysis.

"This will mean mining companies can measure what's coming in and out of their processing plants with greater accuracy, allowing them to monitor performance and recover small traces of gold that would otherwise be discarded," the CSIRO says.

Last year Australia produced around $10 billion worth of gold, although only between 65 to 85% of gold is recovered; the CSIRO says even if there is only a 5% improvement in recovery this will lead to an extra half a billion dollars generated.

{^media|(width)300|(height)45|(ext).mp3|(url)~/getmedia/c20bb773-2bda-4c1e-b522-3fb00151d532/GAAaudio3.aspx^} (Listen to Tickner explain the recovery potential)

Gold has recently experienced a massive slump, after recording record highs and a skyrocketing price over the last few years.

In June gold prices dropped to a three year low as markets went through a correction phase.

Gold prices have been in steady decline in recent months as investors who bought the asset to hedge against high inflation and a weaker US dollar shed their holdings.

Spot prices for gold managed to fall more than eight per cent in a single week after Federal Bank chairman, Ben Bernanke, outlined a plan to wind back massive stimulus measures.

As the price has fallen more and more gold miners have been laying off workers in an attempt to stem cash loss.

This new technology aims to aid miners in getting higher returns out of their ore.

GAA works by scanning mineral samples using high energy x-rays, which activate any gold in the sample which can be picked up by a detector.

James Tickner, the project's leader, said the technology is two to three times mire accurate than 'fire assays', which needs the sample to be heated up to 1200 degrees Celsius.

"The big challenge for this project was to push the sensitivity of GAA to detect gold at much lower levels – well below a threshold of one gram per tonne," he says.

{^media|(width)300|(height)45|(ext).mp3|(url)~/getmedia/a18b35ae-e694-4e0b-a24e-a5076f7475cc/GAAaudio1.aspx^} (Listen to Tikner explain the process)

The entire process can also be automated, allowing for quicker process.

"Fire assay usually involves sending samples off to a central lab and waiting several days for the results. Using GAA we can do the analysis in a matter of minutes, allowing companies to respond much more quickly to the data they’re collecting.

"A compact GAA facility could even be trucked out to remote sites for rapid, on-the-spot analysis," Tickner added.

The new process is also more sustainable as it does not use heavy metals such as lead.

It can also be used across a number of different metals.

"While most of the work we’ve done has been based on the gold industry, the technique can  be modified for other valuable commodities such as silver, lead, zinc, tin, copper and the platinum group metals."

The team is currently aiming to have a full scale analysis facility up and in running in Australia within the next two years.

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