IM MAR 23 March 2023 | Page 38

ORE SORTING
IMA Engineering has recently reduced the sensing interval of its FCA conveyor-based units from 30 seconds to below 10 seconds with the newest generation of technology

Going beyond the belt

Wherever they are positioned , sensor-based ore analysis and sorting solutions are making a difference at mining operations . Dan Gleeson examines the evidence

The concepts behind pre-concentration and ore sorting are not new ; they have existed for decades and been applied in various guises – and with varying success rates – across the commodity space .

The true capabilities of these technologies are only now being understood though , as the evolving digital ecosystem continues to break down the silo mentality that has kept the pit away from the plant , and the datasets coming off these units point towards trends that can make a difference up- and down-stream of where they are installed .
The realisation of the technology ’ s capabilities when embedded into sophisticated digital platforms is spurring adoption and interest at a relentless pace .
These same users are convinced the solutions can not only reduce their operating costs and boost output , but also allow them to continue operating on a sustainable footing with reduced energy and water consumption .
All these traits mean effective particle sorting solutions are highly sought after .
TOMRA ’ s COM XRT 2.0 – the company ’ s largest sorters – are able to operate at 3.5 m / s and analyse particles as large as 125 mm . In one of its largest installations in Saudi Arabia – a nineunit configuration at Ma ’ aden Phosphates ’ Umm Wu ’ Al project – this is facilitating an 1,850 t / h sorter feed operation .
The company is now looking to further refine its offering , answering the calls from many industrial mineral miners to sort down to finer particle sizes .
“ We are working on some mechanical and software advances focusing on smaller particle sizes ,” Jordan Rutledge , Area Sales Manager at TOMRA Mining , told IM . “ While industrial minerals customers might have initially pushed this , everyone is happy about it . Even the metal producers have been asking for such a solution –
they are used to using dense media separation , so have become accustomed to looking at smaller and smaller particles sizes .”
Rutledge was not able to reveal much about these developments when speaking to IM in early February , but , in the industrial minerals space , TOMRA is already sorting down to 4 mm particles with the COM Tertiary XRT . In the diamond space , meanwhile , it can go down to 2- mm-size particles with the COM XRT 300 / FR .
“ What I am able to say is that the mechanical advances are the game changer here ,” she said . “ On our software and processing packages , we have been able to identify almost everything that comes by on a belt or chute , regardless of size , but the challenge has been on the mechanical side for sorting purposes at speed .
“ Many equipment suppliers can sort smaller particle sizes if they are processing less than 1 t / h , but we will be the only company able to sort at this size with the higher throughput tonnages companies are used to .”
As mining companies await these new advances , those in the gold space – especially in quartz-associated orebodies – are benefitting from TOMRA ’ s two-pronged approach to sensorbased sorting .
Leveraging XRT- and Laser-based sorters , TOMRA sorts the feed by sulphide and quartz association .
This may require two sensing units , but the results make it worthwhile , according to Rutledge .
“ While the XRT analysis helps ascertain those particles containing sulphides from above the belt , the Laser system – which is applied on a chute – is able to image the particles from two sides ( above and below ),” she explained .
“ This has proven time and again to provide a
TOMRA investigates the fine print
Particle sorting companies have been refining ore and waste streams for decades , leveraging various sensors and physical separation methods to generate new-found value .
Alongside this economic value generation , they have also been able to optimise ore processing – ensuring only ore is processed in downstream parts of the plant – and reduce energy and water use . In the case of TOMRA Mining , its sensor-based sorting solutions can reduce specific energy consumption by more than 15 %, as well as the amount of water used by three to four cubic meters per tonne of ore , according to the company .
Galaxy Resources ’ Mt Cattlin hard-rock lithium mine , in Western Australia , has installed two TOMRA PRO Secondary Laser sorters to treat 1.2 Mt of ore Galaxy previously stockpiled due to basalt contamination
36 International Mining | MARCH 2023