University of Queensland researchers have developed a state-of-the-art imaging analysis machine set to revolutionalise the mineral separation or flotation process in mines throughout the world.
The Julius Kruttschnitt Mineral Research Centre team invention JKFrothCam consists of a video camera and software package positioned above the swimming pool-sized vats or cells used to separate wanted minerals and coal from unwanted minerals.
The Peak Downs Coal Preparation Plant managed by BHP Coal in central Queensland have already purchased several of the units with many more on order. The company's huge Minera Escondida copper mine in Chile is currently trialling the technology. Chile operation is one of the largest copper mines in the world processing 132,000 tonnes of ore each day with a peak capacity of 6500 tonnes of ore per hour.
Peak Downs Coal Preparation Manager Ian Brake said the plant was currently completing
world-first installation of the FrothCam system for the control of the large froth flotation circuit.
"The full plant installation was approved after the FrothCam had successfully controlled one quarter of the flotation circuit automatically for several months without operator intervention," he said. "The FrothCam system is robust and captures the flotation performance recognition and control strategies of the best operators and applies this to the control of the flotation circuit automatically as process conditions change. This system has the potential to optimise many other areas of mineral processing and mining."
JKMRC project leader Dr Peter Holtham said the unit systematically and consistently monitored the bubble size, speed and texture of flotation froth bubbling over cell lips ensuring maximum efficiency of the process.
JKFrothCam developed as a PhD project by Dr Khoi Nguyen, now a senior JKMRC researcher, five years ago with funding from BHP's Peak Downs mine, the Australian Research Council, the Australian Mineral Industries Research Association (AMIRA) and the Australian Coal Association Research Program (ACARP).
According to the JKProducts manager Peter Cameron, JKFrothCam is now poised to be the most significant development in flotation since in-stream analysis was introduced in the 1970s.
"Miners throughout the world have expressed interest in buying units or clusters of units for each flotation cell in each plant. When you consider the average plant has around 10 cells while large plants such as the Minera Escondida have 80 cells, the system will be a big seller for the University," he said.
Dr Nguyen said for the past 100 years, flotation process monitoring had been considered an art rather than a science. "The downside to this was that everybody had a different way of looking at things. FrothCam provides a consistent, accurate monitoring system 24 hours a day ensuring all cells are overflowing at the correct rate all of the time," he said. "Its strengths lay in the fact that it can rapidly adjust to different light conditions and that it is extremely robust."
Flotation is the crucial separation phase in mineral and coal processing and involves the mixing of slurry (fine ground mined particles) with reagents in the cells then adding air. "Wanted particles stick to the air bubbles and float on the surface forming a froth which overflows the lip and flows on for further processing. What's left in the cell is disposed off as tailings waste," Dr Nguyen said.
JKMRC director Professor Tim Napier-Munn said the project reflected the Centre's strength of encouraging postgraduate students to undertake research which was both academically rigorous and industrially useful.
For more information, contact Dr Khoi Nguyen (telephone 07 3365 5849), Dr Peter Holtham (telephone 07 3365 5857) or Peter Cameron (telephone 07 3365 5908).
