ORE SORTING
digitalisation tool that generates data that can be used simultaneously for multiple applications and these include : feedback to mining operations , ore blending , ore reconciliation , bulk sorting ( waste removal but also to create stockpiles of different quality materials for blending ), diversion to by-pass , feed-forward control to process operators , metal accounting and various other applications . This is the value for bulk sensing on conveyors .
“ Any of these individually could potentially provide a short equipment payback but , combined , they can produce a step change in operational performance .”
Speeding up time-to-mine
IMA Engineering has been around since 1994 , but it is only in the last few years that its messaging and warnings have found a widely receptive audience .
The mining industry – as has been well documented – is renowned for its conservativism , typically looking to refine existing processes as opposed to disrupt the status quo .
IMA , through its various sensor-based solutions , has been showing mining companies there is another way to improve productivity , reduce energy and water use and – increasingly important of late – compress the timelines associated with getting a mine into production .
Jukka Raatikainen , CEO , and Ilpo Auranen , Chairman , explained : “ Our approach includes : faster exploration utilising our Scanmobile drill core scanning and real-time reporting systems , and related bulk ore sorting integrated conceptual mining studies . This is followed by stacking of the ore at an early stage of mining before the concentrator is built by using dry bulk ore sorting methods , which reduces the concentrator commissioning time as the exact quality of ore being fed through to it is known in advance .
“ Further sorting ore from existing waste rock and tailings sites is a source of metals for the ‘ green shift ’ with high potential . And new IMA solutions can help mining companies bridge technological and philosophical ‘ silos ’ from exploration to processing with new data from sensors .”
These solutions are aided by a relentless focus on automating the sampling and analysis that underwrite and verify these processes , to remove human error and measure important ore characteristics throughout the flowsheet .
The company is keeping all this in mind when deploying its bulk ore sorting solutions , which are tied to its IMA Fast Conveyor Analyzer ( FCA ) platform .
IMA has recently reduced the sensing interval of its FCA units from 30 seconds to below 10 seconds with the newest generation of technology . This new-found ability to sort at an accelerated rate – providing potential for higher throughput analysis and sorting – has led to the company winning more projects across the globe , including in South America and Asia .
On projects specifically , Auranen mentioned IMA had secured FCA deployments at three mines owned by a major mining company in recent years , with the potential to add to this in the near term .
To this point , XRF has been IMA ’ s sensor of choice for its FCA solutions , but the company has recently signed agreements with a partner that could see the incorporation of a new laser-based system able to provide particle size distribution ( PSD ) analysis on a conveyor belt .
“ This is applicable , for example , when looking to optimise mill throughput in AG / SAG mills ,” Auranen said . “ Throughput is an important metric in the mill , and waste rock is often harder than ore . If waste rock is fed into the mill , not only does the mill process ‘ waste ’ and reduce the concentrate value / production , it also stays in the grinding mill for extended periods of time , reducing the overall processing capacity .”
Another potential application where XRF-based sorting and PSD analysis could be of help is in heap leaching where the agglomerate size , grade and quality has a big impact on the liquid flow , aeration and wider leaching performance , according to Auranen .
“ In the future , we can look to measure other characteristics beyond ore grade and PSD ,” he added .
One of the other projects IMA has lined up will see the company spend more time in the underground mining environment .
IMA is already familiar with this setup as it is providing sampling solutions for drills with AutoSampler Underground , but it is looking to transfer some of its on-belt FCA learnings to overhead XRF-based systems for LHD payload analysis .
Auranen explained the concept and the rationale for entering such a market : “ The driver for that is the move to large-scale block caving of mining operations . This is an increasing trend for the future – big mines that are big on the surface will be big underground too .
“ Many of the existing block cave mines have autonomous fleets , so we feel we can provide a grade-based recognition system for these fleets as well as automate the sampling and analysis processes that come with these operations , which , as they are large scale , have higher ore heterogeneity than smaller operations .
IMA is looking to use this heterogeneity by carrying out the sorting underground , ensuring the ‘ waste ’ does not have to be carried to surface .
“ That is both more environmentally friendly and economical ,” Auranen said .
He added : “ We believe this will be very big in the future and something we can talk about in more detail .”
Outside of ore sorting , the company is also working on more automated sampling and analysis solutions for a wider range of machines – continuous miners , for instance – as well as creating solutions that minimise the maintenance surrounding automated slurry analysis .
More widely , IMA is advocating for joining all the dots within the flowsheet to enable optimised processes throughout the operation . Raatikainen said : “ One solution for this is measuring the ore grade on conveyor belt every 15 seconds , on average , and , thereafter , analysing the same ore a few hours later in mineral slurries ( online analysis of spot samples every 15 minutes ). The combination of these makes the whole system more accurate and responsive by knowing the quality of ore in advance for adjusting the chemical dosage in flotation and verifying the results with on-stream analysis .
“ Further , we have complemented our system by integrating RFID tags that are placed in blast holes and muckpiles . The tags then move with the ore from mine-to-mill and are read at the onbelt analysis points after the primary crusher and on the mill-feed conveyor , combining the source location at the mine with the analysis results and recovery performance information at the concentrator . The tags also help measure the ore retention time in intermediate stockpiles .
“ This also acts as a quality assurance / quality control ( QA / QC ) system and helps in mine-to-mill reconciliation when comparing the results from each sampling and analysis point with each other .”
The environmental benefits of this type of analysis are set to be displayed in a “ handprint ” calculation IMA is working on with experts from universities in Finland .
A carbon footprint calculates the negative impacts on the environment , whereas the handprint reflects on the positive impact of a product , processes , or actions on the environment .
Sensor fusion in China
HOT ( Chengdu ) Industries Co ., Ltd ( formerly HOT Mining ) says it provides cutting-edge innovations for the minerals processing industry that also satisfy “ planet-friendly ambitions ” by carrying out ore pre-concentration and grade control . It does this using XRT-based sorting , CCD Optical / Colour sorting , AI-backed MR sorting and real-time elemental analysis with the likes of Laser-Induced Plasma Spectroscopy ( LIPS ) and XRF technology .
The Matrix ® CCD Ore Colour Sorter and SorterX ® Intelligent XRT Ore Sorter are the
42 International Mining | MARCH 2023