The magnetic resonance sensing technology uses radio waves to measure all rocks within the mix of feed grade into a processing plant, giving miners the full picture of the heterogeneity of their deposit and the proportion of high grade ores against those of marginal or uneconomic grade.
Unlike other ore sorting solutions, the CSIRO sensor can measure up to 4000 tonnes of material at a conveyor’s operational speed – compared to just hundreds of tonnes with other technologies – making it suitable for large mining applications.
In addition, it can be mounted directly on a conveyor belt.
The technology is suitable for copper, iron and arsenic minerals and was developed by CSIRO’s Mineral Resources Flagship centre over the last seven years.
A six-month trial at Newcrest’s Cadia Valley copper operations in New South Wales demonstrated great measuring success of the chalcopyrite copper mineral, giving the miner insight into the variability of the deposit.
CSIRO’s project team leader, radiofrequency online analysis and control, David Miljak said the data could help boost mineral processing productivity if the sensor was commercialised into an integrated ore sorting solution, which could help miners divert low grade ores from the processing plant, cutting process time as well as energy and water consumption.
But, he said CSIRO could not do this alone and was on the lookout for a commercial METS partner.
“Sorting isn’t just a sensor, we’re just providing a piece of the puzzle,” he said.
“There’s a whole bunch of other things that have to be considered to implement a sorting solution, like where would you put the waste stream, what are the costs involved, would it impact on other processing issues and on the way you have to mine the deposit?
“Our strategy around that is to look for large METS companies to partner with us and use their main knowledge to implement a complete solution – because it can’t be just one party doing all this with a mining client, it needs a concerted effort from different specialists.”
Advanced discussions with some interested parties are already taking place.
If these discussions are fruitful and lead to a commercial outcome, Miljak said the technology had the potential to boost mineral processing efficiencies for copper and iron ore miners.
“I suppose an overall industry problem is declining productivity because of declining grades, and so we see bulk ore sorting as a potential to help in some situations.
“This technology has got the favourable attributes that you can put it on a conveyor, it’s robust enough and it does penetrate the rock very well [thanks to the radio waves] to give a quantitative measurement of a specific mineral.
“So if you stack all those things together, it’s one of the very few techniques that are suitable for bulk ore sorting.
“It’s always about separation though [and] the problem is that if there is no variation of the grade in the deposit then we can’t really do much.
“But if there is variation [and] if it all goes well, there will be a strong competitive advantage for that mining company because they will have a productivity improvement through sorting.
“A boost in productivity, savings of water and CO2 emissions reduction – I think all of these are realistic if we find the right deposit to work on, get a full commercial approach and implement a full sorting trial.
“That’s still a fair way off, there is still a lot of work to get there, but if we can pull it off that would be the benefit.”