ORE SORTING
Metso Outotec stands out among the mining original equipment manufacturers for having publicly acknowledged ore sorting is on its radar .
The Outotec business had a relationship with TOMRA Sorting Solutions dating back to 2014 when the two companies signed an agreement that would see the particle sorting company supply Outotec-branded sorting solutions to the mining and metallurgical industry . Metso , meanwhile , has previously disclosed it was developing “ breakthrough proprietary technology to address the demand of high throughput accurate sorting ”. Close to eight months after the two companies merged to become Metso Outotec , IM put some questions to Erwin Huber , Vice President , Crushing and Conveying Systems , and David Di Sandro , Business Development Manager – Optimisation and Test Labs , to find out the current state of play with ore sorting at the mineral processing major . our expert ’ s tacit knowledge and provides a more reliable way over time to analyse big data generated from online mineral analysis .
IM : Where in the flowsheet do you envisage these solutions going ? EH : The earlier we can remove the gangue from the flow stream , the better our energy efficiency will be by reducing the volume of waste material that is processed by downstream equipment . Deposits in advanced development allow for in-pit backfill bulk ore sorters that may be deployed behind mobile in-pit crushers , or before the coarse ore stockpile where backfilling is not an option . There are several preconcentration technologies that can be applied at each stage of mineral processing and the ideal operation should combine those tools to remove the liberated gangue at multiple stages of the processing plant in order to achieve the most sustainable process ( ie bulk / particle ore sorting , selective breakage , coarse flotation ).
IM : Back in November at your Capital Markets Day , there was mention of ‘ AI-powered Ore Sorting Solutions ’ during a presentation . Can you expand on what this offering might include ? What stage is it at in terms of commercialisation ? DDS : Ore sorting is one of the most exciting recent developments in our industry . With improvements in sensor capabilities and adoption of artificial intelligence ( AI ), this may well become the revolutionary change this industry needs to sustain itself in the face of diminishing grades and orebody quality . EH : With our ore sorting solution development , we are targeting the ability to deliver complete offerings of hardware and sensor-fusion platforms as it relates to both bulk and particle ore sorting . These platforms would utilise AI to optimise the feed material for the downstream process . Metso Outotec is uniquely positioned to understand and optimise that plant feed stream with deep knowledge and almost complete technology coverage in both the concentrator and tailings processing areas .
We plan to bring new solutions to the market in the short term and continuously launch new technologies to increase capabilities and capacities when the developments are mature enough .
IM : Previously Metso has talked about the development of a bulk sorting solution : do these ‘ AI-powered Ore Sorting Solutions ’ fit into that category , or are they more particle sorting solutions ? EH : Bulk ore sorting enables material selection at high throughput flows and particle technology is limited by capacity while bringing the benefit of high accuracy on selectivity .
Bulk sorting is in its early stages in industry and no single sensor can determine minerals content across all ore types and mine sites . This is where AI algorithms play a significant role in ‘ self-learning ’ ore characteristics , mine site by mine site . It also provides great opportunities to do sensor fusion and more accurately determine the minerals content based on outputs from various sensors and sensor types . AI augments
IM : Will the benefits of your solution be felt beyond the crushing and grinding stage ? Do you intend to use the data generated from the ore sorting solutions to benefit the whole downstream flowsheet ? DDS : One of the benefits of ore sorting is more efficient removal of waste from the process feed . Under certain circumstances , this also means removal of deleterious material which otherwise would adversely affect downstream process performance such as flotation recoveries . In these cases , the downstream benefits are intrinsic . The key would be understanding the geometallurgical mapping of all rock types and their mineralogy , so a philosophy of ‘ include or reject ’ can be applied on a metallurgical response basis . This mapping can be improved with SmartTag™ and GeoMetso™ technologies from Metso Outotec . EH : The ability to sort , the geometallurgical mapping and metallurgical response obviously feed back into the block model and allow for more options in the mine plan and life of mine resource recovery , for example with the deployment of low-grade stockpiles . This further enhances the sustainability of the mining operation .
IM : Is the market ready for and receptive to such a powerful ore sorting solution ? DDS : As we all know , for good reason , our industry is full of early adopters rather than innovators . Most operations will need to see the technology succeed elsewhere before increasing their uptake of the technology . The initial implementation will likely occur in partnership with customers whose operations need this technology to be economically viable . EH : The key is to understand the ore variability through the deposit and through the life of mine . Adopting ore sorting as an integrated processing step does not differ that much from testing and sizing flotation circuits , where small changes in ore properties can affect the overall recovery . It is important to understand these changes and how to react to them during operations .
The confidence level in sensor-based ore sorting testing will grow over time . We already see real-life examples where customers report on ore reserves based on lower cutoff grades due to ore sorting .
With all this technology , IMA and Auranen stress the importance of sensor and system verification ahead of starting up full operation .
The company has plenty of potential options for this in its portfolio , including comparing on-conveyor belt XRF data with blasthole sampler-analyser data , or feedback from IMACON online analysers that calculate oxide or elemental compositions in finely grinded dry powders or wet slurries at the processing
plant .
In evaluating the difference between bulk ore sorting and particle sorting , Auranen made a clear distinction .
He said : “ Bulk ore sorting and particle sorting should be evaluated as part of the same process : bulk ore sorting is typically a low cost , high value pre-concentration method for all production capacities , which should be applied in all processes . Particle sorting is a ‘ scavenger ’
sorting method for lower tonnage material flows and for secondary recovery .”
He cautioned that changes in blasting methods in certain markets could inhibit the potential of particle sorting .
“ With particle sorting , you cannot sort fine particles and , if you use intelligent blasting , you will be blasting the ore finer , which could be beneficial to the overall process in most cases outside of iron ore ,” he said . IM
MARCH 2021 | International Mining 55