Australia-based NextOre is onto another ore sorting assignment with its magnetic resonance (MR) sensing technology, this time in Zambia at First Quantum Minerals’ Kansanshi copper mine.

NextOre was originally formed in 2017 as a joint venture between CSIRO, RFC Ambrian and Worley, with its MR technology representing a leap forward in mineral sensing that provides accurate, whole-of-sample grade measurements, it says.

Demonstrated at mining rates of 4,300 t/h, per conveyor belt, the technology comes with no material preparation requirement and provides grade estimates in seconds, NextOre claims. This helps deliver run of mine grade readings in seconds, providing “complete transparency” for tracking downstream processing and allowing operations to selectively reject waste material.

Having initially successfully tested its magnetic resonance analysers (MRAs) at Newcrest’s Cadia East mine in New South Wales, Australia, the company has gone onto test and trial the innovation across the Americas and Asia.

More recently, it set up camp in Africa at First Quantum Minerals’ Kansanshi copper mine where it is hoping to show off the benefits of the technology in a trial.

The MRA in question was installed in January on the sulphide circuit’s 2,800 t/h primary crushed conveyor at Kansanshi, with the installation carried out with remote assistance due to COVID-19 restrictions on site.

Anthony Mukutuma, General Manager at First Quantum’s Kansanshi Mine in the Northwestern Province of Zambia, said the operation was exploring the use of MRAs for online ore grade analysis and subsequent possible sorting to mitigate the impacts of mining a complex vein-type orebody with highly variating grades.

“The installation on the 2,800 t/h conveyor is a trial to test the efficacy of the technology and consider engineering options for physical sorting of ore prior to milling,” he told IM.

Chris Beal, NextOre CEO, echoed Mukutuma’s words on grade variation, saying daily average grades at Kansanshi were on par with what the company might see in a bulk underground mine, but when NextOre looked at each individual measurement – with each four seconds representing about 2.5 t – it was seeing some “higher grades worthy of further investigation”.

“The local geology gives it excellent characteristics for the application of very fast measurements for bulk ore sorting,” he told IM.

Mukutuma said the initial aim of the trial – to validate the accuracy and precision of the MRA scanner – was progressing to plan.

“The next phase of the project is to determine options for the MRA scanner to add value to the overall front end of processing,” he said.

Beal was keen to point out that the MRA scanner setup at Kansanshi was not that much different to the others NextOre had operating – with the analyser still measuring copper in the chalcopyrite mineral phase – but the remote installation process was very different.

“Despite being carried out remotely, this installation went smoother than even some where we had a significant on-site presence,” he said. “A great deal of that smoothness can be attributed to the high competency of the Kansanshi team. Of course, our own team, including the sensing and sorting team at CSIRO, put in a huge effort to quickly pivot from the standard installation process, and also deserve a great deal of credit.”

Beal said the Kansanshi team were supplied with all the conventional technical details one would expect – mechanical drawings, assembly drawings, comprehensive commissioning instructions and animations showing assembly.

To complement that, the NextOre team made use of both the in-built remote diagnostic systems standard in each MRA and several remote scientific instruments, plus a Trimble XR10 HoloLens “mixed-reality solution” that, according to Trimble, helps workers visualise 3D data on project sites.

“The NextOre and CSIRO teams were on-line on video calls with the Kansanshi teams each day supervising the installation, monitoring the outputs of the analyser and providing supervision in real time,” Beal said. He said the Kansanshi team had the unit installed comfortably within the planned 12-hour shutdown window.

By the second week of February the analyser had more than 90% availability, Beal said in early April.

He concluded on the Kansanshi installation: “There is no question that we will use the remote systems developed during this project in each project going ahead, but, when it is at all possible, we will always have NextOre representatives on site during the installation process. This installation went very smoothly but we cannot always count on that being the case. And there are other benefits to having someone on site that you just cannot get without being there.

“That said, in the future, we expect that a relatively higher proportion of support and supervision can be done through these remote systems. More than anything, this will allow us to more quickly respond to events on site and to keep the equipment working reliably.”