PRE-CONCENTRATION & ORE SORTING
is potential for the company to combine this type of analysis with sensor-based particle size distribution ( PSD ) readings – via a tie-up with a partner – to optimise throughput in the mill . When adding ore tracking , via RFID-based tags , IMA can help reconcile not only grade-based data at various parts of the process flowsheet , but also the impact of material hardness on the various processing stages .
“ Because we detect the ‘ markers ’ or ‘ signatures ’ on the conveyor belt , we know the real grades , the material size and where the material has come from ,” he told IM . “ This teaches operations about the waste rock dilution and size considerations that may be impacting recoveries , energy consumption and more in the mill .”
Having already successfully brought its AutoSampler solution for blasthole sampling from the open pit to underground mining environment , the company is looking to make a similar transition with its FCA and other sensor solutions .
IMA has been working on a project to mount its sensors at strategic locations on underground haulage routes to provide XRF-based LHD bucket payload scanning . It now also sees an opening for providing grade-based information and more in underground conveying and hoisting applications .
Auranen explained : “ As mines go deeper and move away from ramp-based infrastructure to shafts , they use hoists to lift ore and waste to surface or to other parts of the underground mine . We can leverage the underground infrastructure already in place – the skip-load conveyors that transport material and the mechanisms for dispatching this material – and provide readings that allow the operators to decide if that 10-20 t load should go to a waste stockpile or to the processing plant .”
These skips are already fitted with weightometers and scales , so the grade-based information can be reconciled against a certain tonnage of material and tracked throughout the operation .
“ In the mining environment there are several steps where the material moves by conveyor and that is an obvious target area for us with the FCA solution , providing an optimisation opportunity ,” Auranen said . “ The skip loading area is just one of these .”
In the ideal setup , IMA would have several FCAs or other sensor-based solutions across the flowsheet to provide as much information as possible to be used for total mine-to-mill process optimisation and reconciliation purposes .
These would be complemented by automated sampling and analysis units , such as the multiplexer-based IMACON 100 for slurry analysis , to provide the quality assurance / quality
The OG7 system successfully underwent testing in Australia and is now in the final stages of commissioning at a large copper mine in Africa
control operations require for improved decision making .
NextOre widening the MR proposition
NextOre also has a strategy for expanding its mining presence underground with a variation of its open geometry , magnetic resonance ( MR ) sensor .
MR technology comes with no material preparation requirement and provides grade estimates in seconds , NextOre claims . This helps provide “ complete transparency ” for tracking downstream processing and allowing operations to selectively reject waste material .
The OGX Sensor – which stands for open geometry and the stated diameter of the sensor – first came to light in Australia as a 3-m-wide unit made by CSIRO to be used in a material feeder setup in 2022 . Testing of this unit was observed by several major mining companies and laid the groundwork for a bigger installation – a 7-m-wide ruggedised antenna that can be positioned over an open-pit haul truck and manoeuvred using a crane and guidance systems . This system successfully underwent testing in Australia and is now in the final stages of commissioning at a large copper mine in Africa .
The advantage of both scenarios , just as with a conveyor , is the ability to make accurate , wholeof-sample grade measurements at high speeds . It is the 3-m OG sensor that could end up being used underground , as Chris Beal , CEO of NextOre , explains : “ We are looking at modifying the OG3 sensor so it can be used to scan material in the bed of a typical underground mining truck . This is a similar process to what we have in place for the OG7 at the surface mine .”
This project has been driven by the needs of a client in Australia with an open stope mine that has observed high heterogeneity within the orebody it is mining .
“ This company sees the benefit of being able to separate material underground and in small open stope and fill conditions where you may be able to avoid trucking material all the way from the bottom of the mine to the surface and back again ,” Beal told IM . “ With the help of the sensor , they could effectively dump material that has been analysed and categorised as waste back into the open stopes .”
NextOre currently has around 40 tonnes of
material at its New South Wales workshop being scanned by this sensor in a static setup to gain a baseline .
In the meantime , the company has plenty of work ahead of it with its Conveyor System Ore Analyser and Mobile Bulk Ore Sorting Plant .
The former has been installed at several mines across the globe , with the highest capacity installation in Chile as part of a 6,500 t / h conveyor application being used for data reconciliation . It has also successfully proven the ore sorting business case on a 2,800 t / h installation at First Quantum Minerals ’ Kansanshi copper mine in Zambia .
The latter Mobile Bulk Ore Sorting Plant – able to sort 100-400 t / h of material on a 900-mmwidth conveyor belt while running at 0.3-1 m / sec – has been used at Aeris Resources ’ Tritton copper operation in New South Wales , where the unit took material on the first surface stockpile from an underground mine .
Beal said the same plant is currently at NextOre ’ s factory being refurbished with a new sensor unit , but there are already three sites looking to use it to compress the timeline normally associated with making a business case for a commercial ore sorting installation .
“ We should be ready to push the plant out of our facility for deployment around April ,” he said in early-February . “ We are currently evaluating three options – in Australia , Chile and Brazil – where the unit could go . It will all depend on how quickly these sites can move in terms of bringing it to the mine .”
NextOre is making plans with its partner manufacturers to build two more units to fill demand for these Mobile Bulk Ore Sorting Plants , with Beal hopeful of servicing all three of these mines in due course .
56 International Mining | MARCH 2024