Gold Miners Could Use X-Ray Technology to Detect Unseen Nuggets

First Posted: Aug 21, 2013 11:14 AM EDT

Gold miners may be getting a bit of help with some advanced technology. Scientists have revealed that gamma-activation analysis (GAA) offers a faster and much more accurate way to detect gold than traditional chemical analysis methods. The findings could lead to saving the minerals industry in Australia hundreds of millions of dollars each year.

So how does GAA work? It scans mineral samples weighing around half a kilogram using high-energy x-rays, similar to those used to treat patients in hospitals. The x-rays activate any gold in the sample and the activation is then picked up using a sensitive detector. This allows researchers to easily see whether the sample is worth further processing.

Yet actually detecting this gold and creating this method wasn't easy. "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 ton," said James Tickner, the project leader, in a news release.

Usually, a gold processing plant only recovers between 65 and 85 percent of the gold in mined rock. Since a typical plant produces around $900 million gold each year, this means there are hundreds of millions of dollars' worth of gold going to waste. Yet this latest technique may help stop this particular issue. Since it's easily automated, GAA is also far quicker than other analysis methods.

"Fire assay usually involves sending samples off to a central lab and waiting several days for the results," said Tickner in a news release. "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."

The next step for the researchers is to partner with local and international companies to get a full-scale analysis facility up and running in Australia. The new technique could eventually help with keeping gold loss to a minimum. This could, in turn, revolutionize the way we mine gold.

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