ORE SORTING
Steinert ’ s XRT ore sorting technology can consistently ensure the quality fluorspar miners need to produce multiple products for their chosen markets , according to Lütke von Ketelhodt . Pictured is a fluorspar installation in Mexico
While XRT ‘ sees through ’ the particles , the other sensors provide surface detection that can augment this ability . von Ketelhodt , who has been in the ore sorting game for more than 18 years , says miners are finally looking beyond the throughput question when evaluating the use of particle sorters , and are starting to see how the quality and accuracy of sorting can benefit them .
Here he references one of the company ’ s biggest installations – four KSS units – at a chromite mine , in Brazil .
“ Here we sort even large 0.5 ft ( 152 mm ) lumps , down to material that is 0.5 in ( 12.7 mm ),” he said . “ With this feed variation , the throughput varies depending on the size . It could be something in the order of 100-150 t / h per machine if the distinction between good and bad material is very clear and the feed variation is consistent . If not , it would be a lower throughput .”
He added : “ With something like fluorspar , for instance , the quality is more important than the throughput . This technology can consistently ensure the quality they need to produce multiple products for their chosen markets .”
And , even in higher throughput mines , von Ketelhodt sees a place for particle sorters .
“ With mines that produce low-grade ores at high capacities , and the mill and process plant are designed and built to handle this ore , particle sorting alone does not make sense ,” he said . “ Here bulk sorting can be utilised as it will improve the grades of this ore , but a particle sorter could be employed at the back end to scavenge value from the discarded bulk sorted waste stream .”
Distinguishing between the two types of sorters – bulk and particle sorters – von Ketelhodt said : “ Particle sorting is a far more exact science . We look at each particle and can finetune it to either recover this marginal , at times , waste piece and , at times , product piece depending on the commodity price or the circumstances on the mine site .
“ With bulk sorting , a lot is based on statistical averages , which means there is a chance you still lose a good portion of material . In this regard , combining both could work in certain applications .”
Looking to what the mining community can expect from Steinert this year , von Ketelhodt mentioned a few key accounts being processed in the near term that would see some “ big mining groups ” acquire the company ’ s ore sorting solutions .
“ They have identified this technology as a gamechanger for their organisations ,” he said . “ Once the first machines are installed , they will then farm those learnings out to the rest of the organisation , which could result in repeat orders .”
The company ’ s sorters are also set to make a difference at Barkerville Gold Mines ’ Cariboo gold project , in Ontario , Canada , this year .
The company , now owned by Osisko Development Corp , has two Steinert KSS sorters to its name , which , upon start-up , will be used to sort ore and waste from an underground narrowvein deposit ahead of transferring this concentrate to the Quesnel River Mill , some 120 km from the mine site .
“ In this type of operation , we are upgrading the concentrate at the same time as reducing transport and milling costs ,” von Ketelhodt said . “ The sorter is playing a major role .”
Making adjustments
Having recently moderated a session titled ‘ The most commonly encountered implementation questions from real-world ore sorting projects ’ at the 53rd Annual Canadian Mineral Processors ' Conference , Harold Cline , Area Sales Manager , North America , TOMRA Sorting Mining , was the ideal person to touch base with for this feature .
Cline said he has been encouraged by the mining industry ’ s changing reception to ore sorting amid the COVID-19 pandemic .
“ The past year has been full of a lot of changes , and the pandemic seemed to be a catalyst for many operations to start thinking differently and approach problems with innovative solutions ,” he said . “ It ’ s been a busy year , with lots of test work and enquiries into implementing sensor-based sorting .”
Cline said the company has had to adapt its installation and service visit protocols since the pandemic hit , but the ability to leverage dedicated service teams around the globe meant site visits were carried out on a “ relatively normal ” basis throughout 2020 .
Still , when service visits were not feasible , TOMRA Insight became an increasingly useful tool .
This cloud-based data platform , which was rolled out to mining customers last year , enables users to improve operational efficiencies through a subscription-based service that provides machine health monitoring and performance analytics in near real time , identifying gaps in production and analysing potential root causes .
TOMRA also started offering up a virtual testing facility in 2020 . This service , which sees TOMRA technicians broadcast live ore sorting
“ Based on what we can assess , we will try to point the customer towards particle sorting , bulk sorting , both , or neither depending on what seems like the best solution for them ,” TOMRA Sorting Solutions ’ Harold Cline says
50 International Mining | MARCH 2021