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Plastic balls bring savings for miners

By: Kate Tilley

August 2, 2013

BRISBANE, AUSTRALIA — A Queensland technology company has invented a simple, yet sophisticated, plastic ball that helps miners track down lost gold.

Brisbane-based Blast Movement Technologies Pty. Ltd. produces blast-movement monitors (BMMs) — plastic balls that are installed near valuable mineral resources in dedicated drill holes before blasting and are easily located after a blast, enabling production teams to know exactly where ore and waste are so they can be separated.

The single-use balls, about 10 inches in diameter, are made of glass-reinforced nylon. They contain directional transmitters that are programmed and activated before a blast and located afterward with a portable detector.

Dedicated software is used to calculate the depth and precise 3-D movement vector of each BMM. That information is then used to quickly redefine ore boundaries to reflect the measured movement, enabling more precise selection of ore and waste after the blast.

Darren Thornton, director and principal consultant of Blast Movement Technologies, said that for a mine producing 500,000 ounces of gold a year, the typical loss of 5 percent is worth about US$35 million a year. Most operations have greater ore loss than that and, in some cases, it has been measured to be as much as 20 percent.

Thornton said a US$200,000 investment in the plastic balls will cover an entire year's blast monitoring program and the benefits will be tens of millions of dollars.

Miners around the world searching for gold, copper, nickel, zinc and iron ore have already been kicking goals with the balls. About 70 percent of the 14,000 balls produced in Queensland this year have gone overseas to mines in Ghana, Tanzania, Canada and Peru.

There has been limited interest from the U.S., but Thornton said BMT, a finalist in the 2013 Australian Business Awards, plans to open an office soon in Denver. "The U.S. is only a small part of [our] market, although we are trying to build that up," he said.

Thornton said new markets are also opening in Finland and Sweden.

With 20 years' experience in applied, practical research in diverse fields, a degree in mathematics and physics, and a work grounding in explosives, Thornton came to mining with a different view of its problems.

He was one of the BMM inventors and in 2005 secured funding for a three-year research project to advance the technology, investigate blast movement and apply it to ore control.

At the same time, he established BMT to commercialize the technology.

"Taking this concept to maturity has certainly been my career highlight, but it would not have been possible without the contribution of a unique group of brilliant individuals. I get great personal satisfaction from knowing we are helping the mining industry to become more efficient and better utilize the world's limited resources," he said.

Thornton's wife, Diane, with a degree in applied science and a master's in information technology, is a BMT co-founder and the company's business manager, responsible for day-to-day operations, supporting customers and staff in manufacturing, purchasing, human resources and accounts.

BMT claims miners lose "hundreds of thousands of dollars" with every blast and, according to its logo, says it "has the balls to ensure you know where your valuable ore ends up after blasting."

Between six and 12 balls are used in each blast. They are color-coded, in red, yellow, green and orange, and built to withstand temperatures from 120° F to minus 60° F. It usually takes less than one hour to locate all BMMs after a typical blast.

"The rock will move during blasting and experience shows it is probably a lot more than you think," Thornton said.

"There is very little that can be done to reduce the movement — you just need to know where it moves. If blast movement is not accounted for in ore control procedures, valuable mineral will be sent to a waste dump.

"Reducing ore loss is pure profit. You still mine the same amount of rock, send the same number of trucks to the plant, and process the same amount of ore. The only difference is now there is more mineral produced. More revenue for almost the same cost — that will make shareholders happy.''

Thornton said BMMs could be used in his home state of Queensland's expansive coal mining industry but, on a dollar-for-dollar basis, finding gold and copper around the globe is more lucrative.