Tag Archives: x-ray transmission

SRK’s stepwise approach to pre-concentration analysis

Having outlined a new vendor-agnostic, lab-based “pre concentration screening test” for mining in part one of this three-part series, SRK is back for part two, discussing the wider pre-concentration evaluation process that this testing fits into

“With any pre-concentration analysis, we need to, first, understand the heterogeneity of the deposit; simply put, if you don’t have heterogeneity, you don’t have the ability to separate the good stuff from the bad stuff and carry out pre-concentration,” Bob McCarthy, Principal Consultant, SRK Consulting (Canada) Inc, says.

With this baseline in mind, SRK Consulting has devised a pathway for companies with drill core at their disposal to analyse whether pre-concentration is a viable option for their flowsheet.

Made up of five steps, this staged approach is deliberately designed to allow companies to pause at the end of each phase to re-evaluate if there is a strong enough case to continue investing the time and finances required.

The heterogeneity analysis is first up, which, under SRK’s evaluation, includes two different approaches based off drill hole analysis: Heterogeneity and Scale and Composite-Sample Relationship Analysis.

“Heterogeneity and Scale involves a process of looking up and down the bore hole at different aggregation distances from every sample and interrogating the sample grade – or net smelter return – against the aggregations above and below that individual sample,” he explains. “We then increase the size of the aggregation to see how that relationship changes.”

Such analysis enables SRK experts to derive the heterogeneity measures typically dubbed ‘waste in ore’ (mineralisation below the cutoff grade within an above cutoff grade zone) or ‘ore in waste’ (mineralisation above the cutoff grade within a waste or marginally below cutoff grade zone). Using a cutoff grade derived from industry benchmarking, the consultants assess the aggregation distance, as resolved in the vertical direction, with the “selective mining unit” (SMU), which typically relates to equipment sizing for mining.

“Heterogeneity and Scale involves a process of looking up and down the bore hole at different aggregation distances from every sample and interrogating the sample grade – or net smelter return – against the aggregations above and below that individual sample,” Bob McCarthy says

“The pitfall some companies go down is picking your SMU to match an equipment size and production rate typically aligned to a corporate or strategic objective,” McCarthy says. “This could mean generating a 12-14-year mine life for a gold operation, or some other investor-led metric that doesn’t necessarily respect the deposit’s heterogeneity.”

The second approach – Composite-Sample Relationship Analysis – allows consultants to further quantitatively assess those waste in ore/ore in waste heterogeneity measures.

“Those parameters have multiple uses after being determined,” McCarthy says. “For example, they help guide in the sample selection – you can even visualise them in 3D with something like Leapfrog. You can also see contiguous lengths of above or below cutoff grade material in ore zones or marginal waste zones, representing what an ore sorter may see. These would be targeted for testing.”

Responding to industry calls, SRK now offers a step between this fundamental heterogeneity analysis and the test work it can conduct at Base Metallurgical Labs’ Kamloops facility in British Columbia, with what McCarthy calls “size the prize” economics. It provides insight into possible pre-concentration strategy outcomes and, just as important, justification to continue to the next step of lab test work.

This process – carried out by SRK on several projects in the past – is designed to allow the mining company and consultant to test pre-concentration strategies from an economic perspective, assessing if an operation should be removing waste from ore or looking to recover above cut-off grade material from “marginal waste”.

McCarthy added: “It is about answering these questions: is it best to remove waste from mill feed, and to what maximum grade of feed, or to extract mineralised material from marginal, below cut-off grade material that increases the mineral reserve? And, of course, do the expected results of this process look promising?”

Gold is a good example here as the economic case study for pre-concentration often only stacks up when a “cap” is applied to the grade of ore subjected to pre-concentration. In other words, the highest-grade material should not be targeted. Even high-efficiency pre-concentration methods incur some metal loss, and any amount of “loss” that occurs in a gold project is difficult to make-up within a conventional flowsheet.

Example of drill core intervals showing waste in ore percentages of up to 80%

The third step in this five-step process is the lab test work McCarthy’s colleague, Adrian Dance (Principal Metallurgist at SRK Consulting), previously outlined in detail in the first article in this three-part series.

The “pre-concentration screening test” leveraging X-ray Transmission based sensor technology can not only indicate pre-concentration amenability, but also provide key inputs into the pre-concentration strategy selection and evaluation, Dance says. He says the testing offers an assessment of pre-concentration potential, as well as an estimate of material bypass and metal upgrade from samples as small as half cores.

Used in conjunction with crushing and screening, this testing rapidly – and cost effectively – assesses the potential for pre-concentration, which can then be applied to scoping or pre-feasibility studies, according to SRK and Base Metallurgical Labs.

Which is where steps four and five of the SRK evaluation – mine planning and mine economics – come in.

“With the heterogeneity measures assigning the distribution of waste in ore, ore in ore, and ore in marginal material in mining block models, the test results reflecting these conditions can be populated into those same models for mine planning,” McCarthy explains.

Typical mine planning steps of pit/stope optimisation, mine design and scheduling can proceed on the assumption of one or more pre concentration strategies, with different versions of mine schedules, reflecting different pre concentration strategies, evaluated.

This type of analysis typically works for a project in pre-feasibility study stage, where engineers can go into the existing block model, bringing the results from the heterogeneity and lab tests into the mine optimisation, design and scheduling process that takes place.

“The challenge is that the scheduling needs to assume a certain strategy – maybe you have determined what that strategy is close enough with the ‘size the prize’, but there are always a few elements you may want to tweak,” McCarthy says. “This could be the mass pull, or waste rejection targets, for instance.”

As a result, sensitivity analyses – mostly numerical tweaks – are embedded in the process.

When not dealing with a pre-feasibility-level project, the SRK team typically rely on an existing schedule that has been run during a scoping study or preliminary economic assessment. This model is modified and tested with different schedule scenarios and pre-concentration strategies based on the heterogeneity measures (step 1) integrated with the lab test results (step 3).

Out of the mine planning step comes a schedule that would go onto the next step: mine economics modelling.

“The model is configured to take in the heterogeneity measures, recovery curves, etc to change the amount of metal reporting to revenue and so forth,” McCarthy says. “Once I get schedules – based on the upgraded block models or it may be a pre-existing schedule – I would then put them into an economic model that has all the levers to pull for different pre-concentration strategies.”

Such a stepwise approach is indicative of where the mining industry is at the moment with vendor-agnostic pre-concentration analysis, enabling companies to get comfortable with the data and assessments as their understanding of their deposit’s heterogeneity grows.

There are potential refinements and fine-tuning opportunities too.

For example, if SRK was gifted with drill core or assay data that was more granular than the 1-2 m intervals typically taken at the exploration stage, it could indicate with greater certainty how particle sorting – typically analysing grades at intervals around a few centimetres – could benefit the deposit in question.

Also, if mine modelling software had matured to the point where block models could be tailored specifically to these waste-in-ore and ore-in-waste characteristics, SRK could segregate the areas in question, instead of applying the type of dilution factors they currently have in place to account for the grade-based realities. This would more clearly communicate the deposit’s heterogeneity to all stakeholders.

Yet, McCarthy and Dance know this will come in time, and are happy to work within the current confines to continue the industry’s education process and identify where the pre-concentration opportunities are

Further discussion on this and what SRK’s pre concentration analysis evaluation – with that embedded pre-concentration screening test – means within the broader mining industry context will follow in the final article in this three-part series later this year

TOMRA’s latest XRT advances open up processing options for miners

When it comes to particle sorting, size is everything. Whether used as a primary sorting method in smaller operations where product purity is paramount to profits, or in a scavenger setup downstream to capture value once lost to tailings, particle sorters are becoming more and more commonplace across the mining world.

They have featured in flowsheets in the industrial minerals space for decades, but they are now finding their way into metal operations all over the world as miners look to boost recoveries, reduce their energy consumption and, in many instances, rationalise their water use.

This makes TOMRA Mining’s latest advances in sensor-based ore sorting all the more significant.

The company is now breaking ground with a new ejection module for its COM Tertiary XRT (X-ray Transmission) sensor-based sorter specifically developed for sorting small particle sizes.

The COM Tertiary XRT Fines sorter, featuring the new TS100C module and the recently introduced image processing unit, is capable of sorting particle sizes down to 4 mm in high-capacity applications with much higher energy efficiency, delivering a high-quality product at low operating costs, according to the company.

The COM Tertiary XRT Fines sorter featuring the new TS100C ejection module has been installed at the TOMRA Test Center in Wedel, Germany

The high resolution TS100C ejection module features a new type of ejector that is four times faster than previous iterations, according to the company. Together with the new image processing unit, it delivers higher precision in sorting small particle sizes at high throughputs.

The mechanical design of the sorter has also been improved by the introduction of a new splitter plate and more precise calibration equipment to ensure the greater precision in the alignment between detection and ejection systems required for fine particles, according to TOMRA.

This has been captured in field tests that started back in May 2022, showing an up to 30 t/h boost in capacity, an increase in product recovery and a reduction in energy consumption.

Ines Hartwig, Director Product Management at TOMRA Mining, told IM on the side lines of the recent SME MINEXCHANGE 2023 Annual Conference & Expo in Denver, that the company had been able to visualise such small size particles previously, but the mechanical ejection function had not been able to keep up.

“This new ejection module is a significant leap forward for TOMRA, and we believe the whole particle sorting setup within the industry,” she said.

And, while the industrial minerals sector was the first one pushing for these developments, Hartwig said she expected the metal miners to also benefit from this.

“We have visited operations all over the world that have stockpiled fine material as they simply couldn’t process it with the technology on the market,” she said. “We’re now opening up many new opportunities for these companies.”

To gain field experience on the new ejection module, TOMRA partnered with a customer who has been running a COM Tertiary XRT to produce high-grade magnesite for more than two years. The sorter removes up to 50% low-grade and waste material from the raw magnesite feed, with particle sizes ranging from 10 to 35 mm at about 20 t/h.

Ines Hartwig, Director Product Management at TOMRA Mining

“After conducting the test work with the TS100C ejection module at the TOMRA Test Center, we were confident that it would be very beneficial for this customer,” Hartwig says. “We showed them the test results and outlined the benefits we expected the module to deliver. As soon as they saw the possible reduction in compressed air use and the consequent cost savings, they were very interested in doing the field trial!”

The customer, the magnesite operation in Turkey, completed several trials, documenting the energy savings and sorting efficiencies. The results showed a 70% reduction in air consumption with an increase in product recovery with a lower mass pull to waste by producing the same product quality, and a capacity increase ranging from 20 t/h to 30 t/h with comparable results, according to TOMRA.

The COM Tertiary XRT Fines sorter featuring the new TS100C ejection module has been installed at the TOMRA Test Center in Wedel, Germany, and is ready to run tests for customers on material samples from their mines, TOMRA says.

Hartwig said she expected existing COM Tertiary XRT customers to upgrade to the new module with the company’s retrofit solution, but there were also many new customers expected to acquire brand-new units.

“There is a significant ‘new’ market out there that we expect to take advantage of this technology,” she said. “The economic and environmental value case at many of these operations can be vastly improved by using the COM Tertiary XRT Fines sorter.”

TOMRA Mining to demonstrate Final Recovery diamond sorter at Electra Mining 2022

TOMRA Mining will showcase its sensor-based sorting solutions at the Electra Mining 2022 exhibition, in Johannesburg, South Africa, in September, showcasing, for the first time, live demonstrations of its COM XRT 300 /FR Final Recovery sorter for diamond operations.

Representatives from its Sales and Field Service teams will also present TOMRA’s offering of advanced digital products and services, such as the TOMRA Insight cloud-based platform and its latest generation TOMRA ACT PC-based system, as well as its portfolio of sorting solutions for the diamonds, metals and industrial minerals industry at the show, which runs from September 5-9.

Corné de Jager, Diamond Segment Manager TOMRA Mining, said: “The Electra Mining Show is the perfect platform for us to showcase TOMRA’s advanced mining solutions. This important exhibition attracts a wide audience – from operators and metallurgists – interested in smart solutions that are simple to operate and maintain, to decision makers who need to be up to date with the latest value-adding technologies. At the event we will have the opportunity to meet them face-to-face and discuss their requirements, giving them a taste or TOMRA’s collaborative approach, product expertise and after-sales support.”

TOMRA will demonstrate the Final Recovery sorter with fine kimberlitic or alluvial ore together with diamond powdered tracers in a Final Recovery and Sort House application. Visitors will be able to experience first-hand the sorter’s capability to produce an ultra-high diamond-by-weight concentrate with an exceptionally low yield by using TOMRA’s proprietary ultra-high-resolution sensor, advanced new image processing and high-precision ejector valve system, the company says. The sorter offers 100% diamond detection within the specified size fraction and > 99% guaranteed diamond recovery with appropriate feed material preparation.

“We are very excited to demonstrate the TOMRA COM XRT 300 /FR sorter,” de Jager says. “It completes our unique partnered diamond recovery ecosystem, which covers the entire process. We are now able to offer our customers a full XRT solution to sort +2-100 mm particles: +4-100 mm particles with our bulk concentration sorters, and +2-32 mm particles with the COM XRT 300 /FR in its Final Recovery, Sort House or small-capacity exploration applications. The sorter offers higher efficiency, better grade, simplified security requirements with fewer sorting stages and a smaller footprint. It reduces complexity and operational costs, and unlocks the potential for previously deemed non-profitable projects and marginal deposits to be economically viable. ”

The COM XRT 300 /FR sorter can also add value to existing kimberlitic and alluvial operations that use conventional bulk-concentration methods like rotary pans, dense medium separation or X-ray luminescence, if installed in a Final Recovery and/or Sort House function after these existing processes. With a contained capital expense, operations can benefit from a quick, simple and significant revenue gain, TOMRA says.

The TOMRA team at the exhibition will explain the full benefits of its complete partnered diamond recovery ecosystem consisting of XRT technology covering the entire process – from Bulk Concentration to Final Recovery and Sort House applications – as well as its advanced digital products and services. These include the newly refreshed TOMRA ACT PC-based system interface and TOMRA Insight cloud-based subscription solution.

TOMRA Mining has 190 sorter installations operating around the world, of which more than 60 are in Africa. It offers installation opportunities in Africa in the metals industry, for example in applications such as lithium, chromite, platinum, manganese and gold.

TOMRA continues to build ore sorting Insight across mining space

Some 18 months after launching TOMRA Insight to mining customers, the cloud-based data platform is making inroads across the North American mining sector, Harold Cline and Jordan Rutledge told IM on the side lines of the MINEXCHANGE 2022 SME Annual Conference & Expo in Salt Lake City recently.

TOMRA rolled out the subscription-based service to mining back in late 2020, with one of the early adopters being the Black chrome mine in South Africa, one of two mining projects that form the basis of the Sail Group’s plans for long-term sustainable chrome production.

TOMRA Insight, the company says, enables sorting machine users to improve operational efficiencies through a service that turns these machines into connected devices for the generation of valuable process data.

Cline and Rutledge, both TOMRA Sorting Area Sales Managers for North America, said numerous customers were now taking advantage of TOMRA Insight across the region, with many more interested in leveraging the continuous data streams coming off a web-based portal stored securely in the cloud.

TOMRA’s Harold Cline & Jordan Rutledge

“This is seeing mine managers able to tap into how operations are performing today, while tracking that against performance over the last day, week, month, quarter, etc,” Cline told IM. “With the help of our support network, these operations are able to achieve more consistent performance.”

With more customers signing up to TOMRA Insight and more data being generated, the pair were confident future iterations of the platform would be able to offer machine-learning algorithms that helped, for example, predict failures or highlight potential areas for operational improvements.

At the show, the pair were also highlighting the ongoing demand for TOMRA’s Final Recovery sorter, the COM XRT 300/FR, which, since launch, has been successfully deployed at the Letšeng diamond mine in Lesotho, owned by Gem Diamonds. The solution has gone on to be rolled out at other operations.

The introduction of the COM XRT 300/FR, TOMRA became the first company in the industry able to supply a full diamond recovery solution using XRT technology from 2-100 mm, with the unit delivering concentration factors of up to one million with limited stages and guaranteeing more than 99% diamond recovery, according to the company.

Outside of diamonds and sorter analytics, Cline was keen to talk up demand from the gold sector for the company’s sorters.

One of the key differentiators of its offering to the yellow metal space is the ability to scan the material with a multi-channel laser sensor. In an ore sorting setup that involves both XRT and LASER sensor-based machines, the TOMRA solution can remove particles containing sulphide minerals using XRT and subsequently leverage laser sensors to remove particles containing quartz and calcite.

TOMRA says its segregated option can potentially improve recoveries in quartz-associated gold applications thanks to a laser chute-based machine that analyses rocks from both sides. Other belt-based laser machines can only analyse a maximum of 40% of the rock’s surface, according to TOMRA.

“In the gold scenario, we are using XRT to sense and sort with sulphide minerals as a proxy,” Cline said. “At the same time, our laser scanner allows further separation capabilities through identification of minerals such as quartz and calcite.”

Vista Gold, which is developing the Mt Todd project in Australia, anticipates that this combined solution could eliminate approximately 10% of the run-of-mine feed to the grinding circuit, allowing the company to decrease the grind size and thereby increase recovery of the contained gold.

The COM XRT 300/FR offers a full diamond recovery solution

Cline added: “In North America, we have three projects in the gold space we’re working on at the moment that appreciate our unit’s ability to analyse the whole of the particle through our chute mechanism, as opposed to conveyor-based systems that can only analyse one angle of the particle.”

While TOMRA offers multiple sensors on its units through its modular platform, Rutledge said the company continues to have discussions on combining its solutions with other bulk sorting suppliers to further improve the process, naming prompt gamma neutron activation analysis (PGNAA) technology as one specific area of interest.

“We very often refer clients on to other companies when our solution may not match their brief,” she said. “At the same time, we have done some flowsheet work to include our solution with others currently on the market and believe it is only a matter of time before a combination of the two comes into a flowsheet.”

TOMRA Mining’s ore sorting solution helps Renison tin mine do ‘more with less’

TOMRA Mining and its X-ray Transmission (XRT) technology has, the company says, provided an effective solution for the extreme conditions at the Bluestone Mines Tasmania JV (BMTJV) Renison tin mine in Tasmania, Australia, with sensor-based ore sorting solution unlocking significant value and delivering environmental benefits.

The Renison mine is 50% owned by Metals X through the BMTJV, and is the only major tin mine in production in Australia with a mining rate of close to 1 Mt/y, according to TOMRA. While slated capacity is 1 Mt/y, the concentrator is restricted to 750,000 t/y.

The mine’s extreme humidity and highly acidic processing water (pH around 4.5) create unique challenges for the sorting process, the equipment and waste management, according to TOMRA.

A complex flowsheet

The underground mine operates a primary crushing system before the material is transported to the surface through a shaft. Once there, it enters the pre-concentration plant, where it undergoes a three-stage crushing, screening and cleaning process. The particles are split into two fractions – 10-25 mm and 25-60 mm – which are fed into two TOMRA XRT sorters. The output consists of two streams: the product, which is transferred to the wet plant, and the waste, which is fed into a TOMRA EM sorter to separate acid-forming sulphides from this waste stream.

In the wet plant, the product goes through primary grinding followed by bulk sulphide flotation. The tailings are processed downstream to concentrate the cassiterite tin mineral through gravity concentration; gravity tails are further treated via desliming and tin flotation. The combined concentrates are fed to a leaching circuit to remove carbonate minerals. After a final wash stage, the concentrate is de-watered and dispatched.

BMTJV approached TOMRA to address two key requirements at the plant. The first was the need to upgrade the tin feed to the plant, as Ben Wraith, Principal Project Metallurgist at BMTJV (pictured below), explained: “The Renison tin operation wanted to achieve economies of scale, putting more tonnes through the front end of the plant without upgrading the back end downstream – we wanted to do more with less.”

The second requirement was to address the environmental issue of removing acid-forming sulphides from the waste.

Following site visits and extensive discussions with BMTJV’s teams, TOMRA proposed a solution that addressed the tin feed quality with two COM Tertiary XRT 1200 sorters and the waste issue with a COM Tertiary EM 1200 sorter. A team from BMTJV visited the TOMRA Test Center in Sydney, Australia, where they observed what the XRT sorter operating at capacity is capable of.

Gavin Rech, Technical Manager at TOMRA, said: “Our XRT stands out for the high spatial and density resolution and its ability to do contrast sorting, identifying fine high-density tin inclusions in the ore with an accuracy that has no equal on the market. On top of that, it can separate it from the acid-forming sulphides, so that we have the ability of pulling the tin into the first product and sending the rest to the EM sorter.”

Gavin Rech, Technical Manager at TOMRA

The two COM Tertiary XRT 1200 sorters went into operation in 2018. Initially, BMTJV’s strategy focused on low reject grades, devoting less focus to achieving the mass reject rate and overall process plant throughput. However, the specific conditions at the Renison mine affected the results achieved. The large variance in run of mine (ROM) particle size distribution resulted in insufficient stability in the feed to the circuit. In addition, the extremely wet conditions in west Tasmania and consequent high ambient moisture content, combined with the high moisture of the ore delivered from underground, further affected the sorting process.

In 2019, a new investigation was conducted into the ore sorting performance and led to a change of direction, where the operation shifted away from targeting low reject grades, towards sorting as aggressively as possible, according to Wraith, moving from a “tin recovery-based” operating strategy to a “mass reduction” one.

“We are getting 20-25% mass reduction, so 75-80% of the materials are going into the wet plant, and we are still achieving 97-98% tin recovery overall across the crushing circuit,” he said. “Pre-concentration didn’t materially impact overall recovery because the tin in the material that is rejected as waste is extremely fine grained and a proportion is associated with sulphides, so it wouldn’t have been fully recovered in the downstream wet plant and would have been lost to tailings.”

This approach, he said, is best for Bluestone’s application as it provides the ability to process 15-20% more tin units without having to upgrade the downstream concentrator.

Wraith added: “Operating the sorting circuit has slightly increased our overall processing cost, but this is more than offset by the large increase in ROM throughput by 15-20% and, thus, tin production, so the unit cost per tonne of tin produced is reduced by almost 10%. We’ve broken multiple production records in the last year in tin units, and this gives us confidence in what we can achieve because the machine performs over and over again if you treat it right and if you prepare your feed correctly.”

TOMRA XRT success leads to upgrade decision

In view of the results achieved with the two TOMRA XRT sorters, BMTJV decided to upgrade the ore sorting circuit with two new, recently launched XRT models with stainless steel internal parts and advanced features such as the TOMRA ACT user interface and the TOMRA Insight cloud-based platform, according to TOMRA.

“The decision to buy new machines was easy,” Wraith said. “The stainless steel will assist prolonging the TOMRA sorter’s life by protecting the unit from our high-moisture and corrosive environment. The more ergonomic design will help our maintenance teams, which is particularly important for machinery operating in these harsh conditions.”

Wraith said the use of TOMRA Insight, the ore sorting company’s subscription-based service that relays and analyses machine data, will “enhance everybody’s understanding and experience of the machines”.

He added: “It will be more of an analytical platform for our metallurgy and maintenance staff, providing ample opportunity to gain valuable information that can be analysed and optimised over time. The one feature I am personally interested in is the particle size monitoring through the machines, which will enhance our overall circuit performance because we have an integrated circuit with the crushing and screening plant. Feed preparation is key to maintain a consistent performance – knowing how well you’re preparing your feed in a live fashion can only end up with a better result.”

TOMRA will also be able to log into the machine and check the daily reports generated by TOMRA Insight, so its technical teams will be prepared ahead of site visits for maintenance or optimisation.

Wraith concluded: “TOMRA has been working with the site maintenance team to tailor solutions to our operating environment, which has been invaluable. TOMRA supported me through site visits, which included equipment inspections, site-based training of our personnel, and an openness to continually improving the technology and finetune it to our site-specific requirements. They assisted the site with troubleshooting, optimisation, discussing the nuts and bolts of the issues as they arose, and finding a solution that works.”

Bartram comes back to TOMRA Mining ready for sensor-based sorting demand uptick

Having left TOMRA Mining more than a decade ago only to return to the Germany-based company in November, Kai Bartram’s re-arrival at the sensor-based sorting firm represents a good time to take stock and reflect on how far the mining sector has come with its understanding and acceptance of this type of pre-concentration technology.

Bartram, now Global Sales Director of TOMRA Mining and a member of TOMRA’s Mining Management Team, was happy to answer some of IM’s questions after getting his feet back under the table in the company’s offices in Wedel, Germany.

IM: How has the mining industry’s appreciation of the benefits of sensor-based ore sorting changed since you left TOMRA in 2010? What trends have led to a wider take up of the technology?

KB: In 2010, sensor-based sorting (SBS) was still seen as a niche technology in the mining industry. Some smaller, more innovative mining companies had seen the potential and effectively implemented SBS, but the mining industry, as such, had not accepted the technology. While in the industrial minerals sector several optical sorters – and, in the diamond industry, mainly X-ray luminescence machines – were operating, the rest of the industry was cautious about integrating sorters into their flowsheets.

That changed slowly with the introduction of Dual Energy X-ray technology. The technology is so robust and perfectly suited to the harsh environment of the mining industry that the economic benefits of pre-concentration became obvious. Another point that has strongly supported the adoption of sorting technology is the fact that average ore grades keep decreasing while energy costs keep increasing.

IM: Diamond and industrial mineral operations were typically the first adopters in the mining sector; what commodity sectors do you expect to see dominate demand for sensor-based ore sorting systems into 2030? What changes to the technology or wider industry understanding have led to this belief?

KB: In the beginning, sorters were seen as small machines, which would never meet the capacity requirements of large hard-rock mineral processing circuits. Therefore, only small mines saw the opportunity to implement sorting as a pre-concentration step in their process. Today, we see that our 2.4-m-wide flagship sorter, TOMRA COM XRT 2.0, can process up to 500 t/h, so that large operations can also implement the technology. An example of such a trend is the Ma’aden Phosphate Umm Wu’al processing plant, where 2,000 t/h are processed with TOMRA XRT sorters.

I am sure we will see more of these bigger projects in many different commodities. Of course, the current market trend is towards ores that are required for the electric revolution, like lithium, copper, cobalt and rare earth elements. TOMRA has proven that we have the right solution to upgrade those ores efficiently and can contribute to more economical output. So, I expect to see more installations in the future.

The TOMRA COM XRT 2.0 units can process up to 500 t/h

IM: Are there any regions more willing to apply these solutions than others? Why is this the case?

KB: If you look at our global reference list, you can see that the larger installed base resides in Europe, Africa and the Americas. The Asian markets are a little behind, but this is easily explained by history. As a European company, we focused more on the better known and established markets. In general, the mining market is a very global industry with big players active in all continents.
I do not believe there are regions more willing to apply the technology than others. It is just a matter of supporting all regions in the same way. TOMRA is investing heavily to ensure we have a good global support network, to be there for and with our clients.

IM: Do you expect to see more collaboration with OEMs over the next decade when it comes to implementing ore sorting solutions with process flowsheets? How do you see the input of both TOMRA and OEMs benefitting the wider mining industry?

KB: Collaboration is essential in any industry. We need specialists who are experts in their field, and TOMRA is one of the global leaders in sensor-based sorting. In order to achieve the best results in one field, one must focus. Therefore, big projects can only be undertaken by a group of companies or experts who collaboratively work together. We, as a solution provider, are very dependent on well-engineered and integrated plant designs and believe we have to collaborate and have close relationships with plant builders to ensure the best possible solution for our clients.

Southern Innovation set for exploration scanning, ore sensing growth with Russell appointment

Southern Innovation, a developer and manufacturer of state-of-the-art real-time materials analysis equipment for the global mining industry, says it has taken a strategic step forward in sales and marketing with the appointment of Steve Russell as Head of Sales and Business Development.

Russell, currently Director of Mining at Scott Automation & Robotics, joins the Southern Innovation team in mid-January 2022 in a role that is expected to drive growth in the company’s key areas of rig-mounted exploration scanners and conveyor-mounted ore sensing/scanning, especially in bulk ores, and looking to near-term applications in base and precious metals.

An engineering professional with a strong background in mining as well as sales and marketing, Russell has previously driven several step-change innovation and automation strategies in the mining industry, according to Southern Innovation.

Southern Innovation, Managing Director David Scoullar, said this appointment will drive strategic growth that has been in the planning stage for a considerable time.

“Southern Innovation has a solid and conservative business base, built off a unique foundation of robust, patient and home-grown development of much-sought-after signal processing technology,” he said. “We have worked closely with some of the most respected and sizeable international mining companies in R&D, and we are now confidently transitioning to grow product sales.

“Our clear objective is to help our customers to improve productivity as well as reduce waste in minerals identification, extraction and processing as the industry drives to net zero emissions by 2050.”

Southern Innovation’s key proprietary products are known as DrillScan™ and GradeScan™.

DrillScan (pictured above, working in the Pilbara of Western Australia) was developed in close collaboration with BHP and is an X-ray Transmission scanner that bolts onto the drill chain of RC drill rigs, performing accurate and continuous analysis while drilling. Results from field use demonstrate more than 95% correlation between continuous, real-time analysis and post-drilling XRF lab-based grade analysis of contemporaneous samples, according to the company.

GradeScan™, meanwhile, is an online, real-time conveyor-mounted X-ray scanner capable of characterising sampled bulk ore in real time at 1 mm resolution across multiple dimensions, according to the company. It features full spectrum scanning, enabled by Southern Innovation’s patented digital signal processing technology, SITORO® Accelerated Analysis.

Steinert XRT ore sorter testing shows promise at Northern Minerals rare earth project

Northern Minerals Ltd has progressed its ore sorting project enhancement initiative with the commissioning and testing of the Steinert sorter system, and is now producing ore sorted material and converting this to a 30% total rare earth oxide (TREO) concentrate in its’ Browns Range beneficiation plant in Western Australia.

Northern Minerals’ CEO, Mark Tory, said: “The construction, commissioning and testing of the ore sorter circuit marks another milestone in the development of the Browns Range project.

“The positive bulk sample tests confirm the effectiveness of the ore sorting circuit on the Wolverine ore to significantly increase the head grade to the mill which is expected to result in higher production rates and lower operating costs for a full-scale operation at Browns Range.

“It’s also pleasing to see the initial ore sorting tests the Banshee ore showing promise which, if shown to be effective in future tests, has potential to significantly increase the Browns Range mineral resource estimate.”

He added: “Being able to test and operate the ore sorting circuit in conjunction with the pilot beneficiation plant is providing extremely valuable data that you just can’t get from small bench-scale tests and this will feed into our feasibility study for a potential commercial scale heavy rare earth operation at Browns Range.”

The ore sorter system was constructed during 2020 and 2021 and commissioned in June 2021. The sorter that was installed is a 2-m wide Steinert sorter that uses X-ray Transmission (XRT) and laser detectors to identify rare earth mineralisation.

The sorter has been run over two test campaigns, which included 41 test runs processing 5,300 t of ore from the run of mine stockpiles largely coming from Wolverine ore, and five test runs on Banshee ore that was bulk sampled from a surface costean that provided 285 t of Banshee ore.

The tests have confirmed that simultaneous sorting of two size fractions is possible on the sorter, allowing a single machine to sort both sortable size fractions (10 mm-25 mm and 25 mm-75 mm), Northern Minerals says. The sortable fraction (>10 mm material) of Wolverine ore can be successfully sorted (90% TREO recovery in 50% of the mass) and, when combined with non-sortable fines, achieves a 45% grade increase to the mill and over 95% TREO recovery when feeding a 0.9% TREO ore.

The sorter system is now being run to produce feed for the beneficiation plant and 4,479 t of Wolverine ore have been processed through the ore sorter circuit to the end of August. Processing of the Wolverine ore sorted material in the beneficiation plant has resulted in better recoveries in the magnetic separation plant and flotation plant compared with feeding unsorted ore, the company says. A bulk sample of 50 t of 30% TREO rare earth concentrate has being produced for test work by facilities identified with likely future capability and capacity to process the heavy rare earth xenotime concentrate produced at Browns Range.

Bulks sample tests have highlighted some key factors to consider for ore sorting that cannot be determined at bench scale using vendor equipment in laboratory settings. Understanding the impact of these factors is critical to including an ore sorting circuit in a full-scale processing facility.

Initial sorting tests of the Banshee ore have shown that the highly oxidised surface material contains a large fines fraction and that the grade of the sortable fraction (ie >10 mm) can be doubled recovering more than 60% of the TREO in 25% of the mass. An additional bulk sample is being extracted from deeper in the costean and three diamond drill holes are being drilled for further test work.

The bulk ore sorting test work is a key input for the full-scale beneficiation plant feasibility study currently underway, which will also leverage off the substantial technical, operational and economic data from the R&D test work at the Browns Range Pilot Plant since 2018, the company says.

Wescoal after RoM upgrade with Acrux, IMS Engineering XRT ore sorting solution

Acrux Sorting Technology has announced that its advanced sensor-based sorting technology is to be deployed at a Wescoal Holdings Ltd-owned coal mining operation in South Africa.

Acrux subsidiary, Acrux Sorting Coal (ASC), has signed a coal beneficiation agreement with two wholly owned subsidiaries of Wescoal, whereby ASC will deploy advanced sensor-based sorting technology to upgrade lower-grade coal from the mines.

Under the agreement, ASC will provide a fully funded turnkey crushing, screening and sensor-based sorting solution centred around advance dual-energy X-ray Transmission (XRT) unit to process run of mine (RoM) coal.

The plant is to be designed, constructed, commissioned, operated and maintained by IMS Engineering Limited, Acrux’s partner on such ore sorting projects. IMS Engineering is a subsidiary of Germany-based HAZEMAG & EPR GmbH.

ASC’s sorting solution offers significant economic benefits as coal resources can now be upgraded to be included as a saleable product, which will reposition the mines along the cost curve, it said.

Paul Bracher, Managing Director of IMS, said: “The XRT technology has proven its ability to upgrade RoM coal through rejecting material that has sulphur or ash content that exceeds programmed parameters.”

The solution will also have a positive environmental impact as no water is used during beneficiation, and the carbon footprint is reduced through the optimisation of transportation and materials handling.

Wescoal’s Executive Director, Thivha Tshithavhane, said: “This sorting technology solution will enable us to impact on ESG, while creating shareholder value from optimising our coal resources at no capital investment.”

Sean Browne, ASC’s Chairman and Group Founder, added: “Partnering with Wescoal underlines our commitment to driving sustainable innovations that reduce the environmental impact of mining.”

TOMRA boosts sensor-based ore sorting process with key updates

TOMRA Sorting Mining has introduced the TOMRA ACT user interface together with a new image processing pipeline and additional process data for TOMRA Insight, all of which will, the company says, enable improvements in the overall sorting process for greater productivity and profitability.

The new TOMRA ACT graphical user interface (UI) brings a fundamental change in the way customers interact with their machines, making it easy to control the work flow in their sorting process with simple, intuitive touch gestures and actions on the screen, according to the company.

The UI provides sorting information and real-time process data at a glance through easy-to-understand graphics. With this clear information, the operator can better monitor the sorting process and make fast adjustments at any time, the company claims. The quick feedback on machine performance and throughput enables them to optimise the process, maximising productivity and efficiency.

Ines Hartwig, TOMRA Product Manager

Ines Hartwig, TOMRA Product Manager, explained: “Throughout the development process of TOMRA ACT, we conducted many in-depth discussions with our customers to ensure we provided them with an interface that would improve the performance of their sorters, benefitting their business. We have been testing it with customers and the feedback has been very positive; in particular about the ease of use, even remotely, which facilitates controlling the process and adjusting settings.

“With the new interface, customers interact with their sorters in a much more intuitive way and they have better guidance on how to improve the overall handling of the sorters. As a result, they will be able to improve the productivity of their sorting plant and the profitability of their mining operation.”

TOMRA is introducing the new UI on all its current X-ray Transmission (XRT) sorters and is planning to extend it to other machines in its offering at a later stage. Upgrade packages to retrofit previous models of its XRT sorters will also become available.

The new Image Processing Pipeline, meanwhile, analyses the data sent by the sorter’s sensors and cameras. This solution provides TOMRA with even more flexibility to adjust and customise the image calculations according to the application and the customer’s specific requirements to achieve the best possible sorting results.

The enhanced image processing solution also collects detailed process data, such as information on particle size distribution of the feed, belt occupancy for insights on feed tonnages, or data relating to the health of the sorter. All these statistics are fed to TOMRA Insight, the cloud-based data platform, adding to the process information it has already received. TOMRA said: “This enables customers to improve the overall sorting process further, taking fast action when changes occur in upstream equipment or in the material’s composition. They are able to better monitor and control their processes, the feed material and the sorted fractions, improving their profitability.”

The new enhanced Image Processing Pipeline, and additional data fed to TOMRA Insight, have already been introduced on TOMRA XRT sorters and will in the future be extended to other products.