TOMRA

QMAG Pty Limited, part of the Refratechnik group, owns the Kunwarara deposit of cryptocrystalline magnesite – one of the world’s largest – located in Central Queensland, Australia. It mines the ore using and open-pit method and processes it into high quality fused (FM), dead burnt (DBM) and caustic calcined (CCM) magnesia products at the nearby Parkhurst facility. It supplies the refractory, chemical, agricultural, environmental and hydrometallurgical sectors with its high-quality magnesia products.

QMAG was an early adopter of sensor-based ore sorting, and is in fact the longest continuous user of this technology in Australia, having installed its first Ultrasort laser machine in 1994 and a second one a few years later. The ore was fed through a Dense Media Separation (DMS) system, using drum and Cyclone separators, then the Ultrasort sorters removed the sandstone, gravel and dark coloured dolomite from the product.

After over 22 years in operation, the Ultrasort sorters were becoming antiquated and could no longer be supported. “It came to a point where the Ultrasort sorter was removing the dolomite, but the background lime was still quite high, and this was not giving us the best opportunity to create the product that was required by the Parkhurst processing plant,” explains Josh Dawson, Production Superintendent at the QMAG mine. A new solution was needed, and TOMRA suggested its X-Ray Transmission technology.

TOMRA’s XRT sorter halves heavy media usage and extends the life of the deposit

In 2016, a TOMRA XRT sorter was installed as a stand-alone plant on site. “It was a trial that management at the time got very excited about: they could see that this could be the future moving forward,” says Josh Dawson. “It was a success story: we could now process very high calcium content material that we couldn’t do as effectively with the DMS or laser sorting equipment.  This gave the ability to produce much lower calcium content magnesite grades suitable for our customers,” adds Alex Padya, Process Engineer.

In view of these results, in 2018 the XRT machine was moved into the sorting plant, where it replaced the remaining Ultrasort that had reached the end of its life, and the DMS drum was decommissioned: “With this decision, we halved our heavy media usage in that part of the circuit and went to a standalone XRT circuit,” says Josh Dawson. As a result, the XRT circuit has delivered significant savings in energy and water usage, and increased the plant’s efficiency.

The TOMRA XRT sorter has exceeded expectations, as Josh Dawson explains: “When we originally made the business case, we thought that it would be used to upgrade the lower quality magnesite ores to produce grades suitable for agricultural purposes, while the heavy media cyclones would make our lower silica materials for other applications. However, by collaborating with TOMRA to optimize the performance of the XRT unit, we can now turn agricultural products into much higher grades required by the Parkhurst processing plant.”

TOMRA’s XRT sorter has also extended the life of QMAG’s deposit: “We were at the point where we thought that a lot of our ore body wasn’t going to achieve the grade for some of our lower end products. The TOMRA XRT machine proved that we could now mine those deposits and turn them into useful product for the higher end applications”

TOMRA XRT technology with TOMRA support: agility, simple operation, easy maintenance

“It’s a very easy machine to operate,” explains Alex Padya. “We have three specific sorting programmes depending on the feed material to get a very intensive, mild or slight rejection rate. Once set up, you virtually leave the sorter to do its job.” Josh Dawson adds: “Having programmes pre-set in the machine instead of using the slidescale takes out human error and makes it all very seamless for us.”

Switching programmes is very simple and quick, which makes the TOMRA XRT sorter exceptionally agile in responding to the frequent variations in the material that comes from the ore body at QMAG’s deposit. If the material coming from a particular part of the deposit doesn’t yield the desired results, TOMRA’s team is always ready and quick to make the necessary adjustments to the programmes.

XRT sorting:  opportunities for future

The results were so positive that QMAG updated its plant replacing the 6-year-old unit with a new TOMRA XRT sorter. In addition, a second unit has now been added to further increase production capacity through this process route. QMAG is currently considering the possibilities that ores sorting technology can open up for the future.

“We see that the technology is improving to the point where we’re starting to consider that XRT can potentially do what the heavy media can do, and in some respects better.” affirms Josh Dawson. Alex Padya agrees: “Over the last few years we have done a lot of runs without going through the cyclone, going straight to the XRT sorter, and ending up with the final product.”

Josh Dawson concludes: “We are looking as a business for our next stages, potentially moving away from the traditional heavy media, and I see a future of a lot more ore sorting technology at QMAG. The technology is moving fast and TOMRA is a leader in this technology.  We are excited to see what technology TOMRA develops next.”

Further information:
TOMRA
www.tomra.com/mining

The global demand for lithium is soaring, driven by the growing adoption of electric vehicles and grid-scale lithium-ion batteries for energy storage. Some forecasts project the demand to reach as much as 1.5 Mt of lithium carbonate equivalent by 2025 – triple what it was in 2021 – and over 3 Mt by 2030.

In the face of such a surge in demand, lithium supply is struggling to keep up. While new projects are set to increase lithium mining capacity in 2023 and 2024, the rise in electric vehicles sales will continue to put the supply under pressure.

These trends translate into a tremendous business potential for mining operations. However, as new projects will struggle to keep up with demand, this potential comes with the challenge of extracting as much lithium ore from all mines as efficiently as possible, while meeting increasingly stringent environmental requirements.

Basalt contamination: the challenge in lithium mining

The main challenge in lithium mining comes from basalt contamination. This high-iron, barren material has a high density very similar to that of spodumene. It means that when dense media separation (DMS) is used as the primary spodumene concentration process, basalt is concentrated with spodumene, contaminating the final product.

This issue can be addressed by selectively mining high grade ore, but contamination is unavoidable, and this approach ultimately results in a substandard product unsuitable for sale at market rates. This contaminated product is usually stockpiled, leaving valuable lithium resources unexploited. The DMS and crushing circuits utilized to produce lithium concentrate from ore are extremely energy intensive, and carrying contamination through the plant decreases productivity and increases costs.

Mining operations under pressure to meet the soaring demand need to maximize the efficiency of their processing plants, using their capacity effectively to extract as much valuable lithium from their mines.

The solution to this challenge is available from TOMRA Mining, the leader in sensor-based sorting with a proven track record in designing and building the largest, high-capacity sorting plants in the world. TOMRA’s proven technologies are able to effectively remove basalt contamination before crushing, optimizing the capacity of the processing plant, reducing energy consumption and waste, as well as lowering the environmental impact of the process. They allow mining operations to consistently achieve the required grade of the product and expand their resources to include more iron and basalt contaminated ore bodies.

The solution: unlocking untapped value with sensor-based ore sorting

TOMRA’s industry-leading sensor-based sorting solutions rely on color cameras, X-Ray Transmission sensors, and multi-channel scanning lasers to sort the ore prior to the downstream wet processing. The sensors analyze every single particle, identify the ore and waste in milliseconds, and high-speed air jets direct the particles accordingly to the product or waste chutes, processing at a capacity up to 350t/h in a single sorter.

These high-speed sensor solutions are capable of sorting a wide size range – from around 6mm to around 200 mm – to maximize the removal of iron and basalt from the feed. With these technologies, it is possible to minimize the unsorted fines that are discarded or stockpiled, and it has been extensively proven that they are effective in consistently reducing the contamination of the ore to less than 4%.

This was the experience of Galaxy Resources at its Mt. Cattlin Mine in Western Australia, where a TOMRA PRO Secondary Laser sorter has been in operation since 2021 to reduce basalt contamination in the pegmatite-hosted spodumene. Since the first day of operation, it has met and exceeded specifications, consistently achieving less than 4% basalt in the concentrate.

Operational efficiencies can be further improved with connectivity to the cloud-based subscription service TOMRA Insight, which turns the sorters into connected devices that generate valuable process data. Mining operations are able to measure the contamination level in real time, and hence the mining quality. They can also monitor the distribution of the particle sizes, and consequently the efficiency of the upstream crushing and screening equipment. TOMRA Insight also gives visibility on the individual sorter’s availability and usage, helping to optimize the process. In addition, it enables the operator to accurately track any faults as they occur and improve the maintenance processes, so that the sorting plant is always operating at its best.

A partnered approach for a tailored solution

TOMRA works in partnership with clients to develop the tailored solution that matches their requirements. It brings its in-depth understanding of the process and expertise, helping clients from the development phase to purchasing and plant integration with quality test work on samples from the mine at its test center and flowsheet guidance. Its solution perfectly integrates the sorting into the overall process stream, for seamless operation. The sorters are specified to match the capacity of the crushing and screening plant, and downstream wet processing plant, maximizing productivity.

This was the approach TOMRA adopted for the design of the world’s largest lithium sorting plant for Pilbara Minerals in Australia. It worked closely with the client’s metallurgical team, completing extensive testwork at the TOMRA Test Center in Sydney, running sample ores from the mine at capacity on production sorters. Based on the results of the testwork and its experience and ability to provide expert local support, TOMRA was awarded the contract. The involvement of the TOMRA team extended beyond testing and supply of equipment to include assistance with the plant layout and understanding of the implications of sorting on the upstream mining and downstream process of the ore, adding to the efficient operational ramp-up and technical optimization.

TOMRA’s close relationship with its clients continues after installation and commissioning of the sorting plant, to keep it operating at its best with tailored service agreements.

With TOMRA’s sensor-based ore sorting solutions, mining operations can not only improve the efficiency of their processing plants, but most importantly unlock value from stockpiled materials and even expand their resources, exploiting ore bodies with higher contamination or search for new mining opportunities in areas with higher iron or basalt content.

Further information:
TOMRA
www.tomra.com/mining

The priority at the top of the list of every diamond producer is to maximize diamond recovery, whilst optimizing costs as well as acting on the growing pressure to address corporate social responsibility and environmental issues.

TOMRA’s holistic approach and cutting-edge technologies have proven to deliver consistently exceptional recovery rates, significant cost savings, operational advantages and a smaller environmental footprint. In particular, its complete diamond recovery solution, unique on the market, is attracting fast-growing interest of diamond producers of all sizes – from large-scale operations to small mines – from different parts of the world. TOMRA is receiving increasing enquiries from existing and new customers, looking to update their plant or complete the process with TOMRA’s revolutionary Final Recovery sorter.

Live demonstrations reveal the full potential of TOMRA’s Final Recovery sorter

A key element of TOMRA’s full solution is the COM XRT 300 /FR Final Recovery sorter (Figure 1), which the company has been demonstrating at its Demo Rooms in Wedel, Germany and Johannesburg, South Africa. These demonstration facilities are proving particularly valuable for diamond operators, who have the opportunity to experience first-hand the unique benefits of this revolutionary and easy-to-operate compact final recovery sorter. They can watch accurate demonstrations of typical final recovery, sort house and single particle sorting functions, across various size fractions with either kimberlite or alluvial ore, and experience sorter outputs at various feed rates exhibiting actual on-mine conditions. The TOMRA operator can show them how their unique operational requirements would be addressed on a live easy-to-use HMI (Human Machine Interface) panel.

“The biggest advantage of these demonstrations is that the customer experiences the extremely low yield – that is the ultra-high diamond-by-weight concentrate – delivered by the sorter,” explains Corné de Jager, Diamond Segment Manager TOMRA Mining (Figure 2). “This in turn highlights the significant downstream benefits with regards to hand sorting and security. What’s even more impressive for them to see is the exceptionally low amount of gangue ejected with the diamond concentrate, even for the difficult-to-sort ultra-fine size fractions.”

TOMRA has also demonstrated the COM XRT 300 /FR sorter at the Electra Mining Show 2022, performing simulated operational production runs for the entire duration of the exhibition. The sorter was fed with fine alluvial ore, which had diamond dust tracers and diamonds added. “This realistic and live operation drew a never-ending stream on show goers,” says Corné de Jager. “The live demo show has resulted in numerous enquiries and sales. In fact, a ‘hands-on’ CEO of a large diamond operation had lengthy discussions with the TOMRA team on site. In front of the crowd, he asked us to process 1 kg of alluvial gravel and to include 150 diamond tracers and 10 diamonds. The sorter delivered a perfect result, ejecting all 160 added tracers and diamonds, with minimal ore particles. The crowd cheered, while the CEO shook hands with our TOMRA design specialist.” 

TOMRA’s unique complete partnered diamond recovery solution

TOMRA is the only manufacturer to offer a complete Partnered Diamond Recovery Ecosystem – a full recovery service from 2mm to 100mm with a flowsheet covering the entire process – from high-capacity Concentration (+4-100mm) to Final Recovery and Sort House applications (+2-32mm).  It includes a detailed analysis of the diamond producer’s requirements and operational needs, the collaborative development of an X-Ray Transmission (XRT) technology-based flowsheet, all the way to installation. After commissioning, TOMRA remains at the side of the diamond producer, to provide on-site and advanced remote support with specialized services and training. The complete solution can also include secure cloud computing benefits of the optional web-based TOMRA Insight service, that offers online and near real time performance metrics of all the sorters.

TOMRA is today the world’s leading supplier of X-Ray Transmission (XRT) diamond recovery technology, having recovered some of the largest and rarest gemstones in history. The extremely precise detection and ejection of even the smaller particle sizes, proprietary image processing and large capacity of TOMRA’s XRT sorters deliver exceptionally high concentration factors and recovery rates in high tonnage diamond concentration applications. In fact, its promise to customers is simple: 100% detection in the specified size range, irrespective of luminescence profile or coating, and a guaranteed diamond recovery greater than 98%. This consistent performance has allowed diamond mines to revolutionize the entire process plant design.

In Final Recovery, the remarkable performance of TOMRA’s XRT proprietary ultra-high resolution sensor and precise ejection technology has revolutionized this stage of the process to efficiently deliver recovery rates greater than 99% along with an ultra-high diamond-by-weight concentrate with yields as low as 0.05%. This in turn has created a unique proposition for the significant reduction of traditional hand sorting, with higher capacities than existing single particle sorters.

Further information:
TOMRA
www.tomra.com/mining

TOMRA Mining invests in its operations in Australia to meet the rising demand for sensor-based sorting and be close to customers on the West Coast – the heart of the country’s mining sector – with the opening of a second office in Perth, the appointment of Jordan Rutledge as new Sales Manager based at the new location, and the extension of its local support and service team. The company also supports its Australian customers with its well-established office and Test Center in Sydney.

TOMRA Mining has a well-established presence in Australia with installations operating in a variety of applications including lithium, industrial minerals, polymetallics and gemstones.It has operated  in the country since the 1990s when Ultrasort entered the market, before being acquired by TOMRA in 2009. Over the years, its business has grown in response to the evolution in the industry: “The diamond, lithium, tin, tungsten, battery and strategic minerals sectors, as well as other progressive sectors that are open to new technology, have driven sensor-based sorting into the main mining process flow and design,” explains Gavin Rech, Technical Manager at TOMRA. “The focus on Environmental, Social and Governance and on reducing energy consumption has further contributed to this trend.”

Jordan Rutledge is appointed TOMRA Mining Area Sales Manager Australia

In order to meet the rising demand for its industry-leading technology, TOMRA has decided to invest further in its operation in the country. It has strengthened its team with the appointment of Jordan Rutledge as Area Sales Manager for Australia, who brings to the team her extensive experience and know-how. Having completed a BS and MS in Materials and Metallurgical Engineering from the Colorado School of Mines, as well as programs in Europe and China, she has spent her career in the mining industry focusing on mineral processing. She has worked on projects in North and South America, Asia, Europe, Africa and Australia. In the last 4 years, she has focused on North American projects for TOMRA Mining.

A new TOMRA base in the heart of Australia’s mining industry

Jordan Rutledge has led the opening of the new TOMRA Mining office in Perth (Figure 2). “Western Australia is the heart of the mining industry in Australia, and with the uptake of sensor-based sorting in the sector we are seeing a fast-growing demand for our technology,” says Jordan. “We have a large number of projects and investment going into sensor-based sorting, and we are gearing up for many more opportunities, particularly in the battery metals space, with the unique solutions that we can provide lithium mining operations. With the new office in Perth, we can be on the ground and visiting our customers on the West Coast very quickly, as they are just a short drive or flight away.”

A dedicated sales and service team

TOMRA Mining has also set up a dedicated team based at the new Perth office.  Jordan in charge of Sales, is joined by Project Coordinator Gianni Mazzella, who runs TOMRA Mining large-scale projects. Also on the team is Adriaan Olivier, Service and Project Manager APAC, who has been supporting TOMRA customers in South Africa and Sydney for the past 5 years, as well as two Service Engineers – with two more to come later in the year. The team will be working closely with the Sydney office and Test Center, with the backing of TOMRA’s global support structure.

“We identified a need to invest further in all the opportunities on the West Coast of Australia and to be closer to our customers in the area. This will facilitate the kind of close collaboration that is the hallmark of TOMRA Mining,” concludes Jordan Rutledge.

Further information:
TOMRA
www.tomra.com/mining

TOMRA Mining’s unique experience in the design and installation of large-scale ore sorting plants and its collaborative approach was the key to the successful design of the world’s largest lithium sorting plant. The installation has already started and is expected to reach completion in late 2023.

Pilbara Minerals owns the the world’s largest, independent hard-rock lithium mine. It is located in Western Australia and produces a spodumene and tantalite concentrate. By pursuing a growth strategy to become a sustainable, low-cost lithium producer, the company has become a major player in the rapidly growing lithium supply chain. This investment will ensure the expansion of its large-scale operation in order to meet the increasing demand for lithium driven by sustainable energy technologies such as electric vehicles and energy storage.

“This new facility to be constructed at our Pilgangoora Project will be the world’s largest lithium mineral ore sorting plant. TOMRA’s experience in large global sorting installations, innovative technology, and ability to provide local support were significant factors in our decision to work with them. From the start, the TOMRA team has been working side by side with us and our engineering partner DRA Global to deliver this important project” Dale Henderson, Managing Director and CEO, Pilbara Minerals

Processing contaminated ore: a key challenge for the lithium industry
As part of this expansion project, Pilbara Minerals turned to TOMRA Mining for assistance to address the key industry challenge in the processing of spodumene feed ore contaminated with barren host rock.

TOMRA has 50 years’ experience in sensor-based sorting technologies and has designed and built 90% of the world’s large-scale mining sorting plants with a capacity above 300t/h. These include plants such as the Ma’aden Umm Wu’al project, which is operating at 1850t/h, or the Lucara diamond operation which runs 15 sorters. Specifically for the Pilbara Minerals project, TOMRA Mining offers effective ore sorting solutions with high sensor resolution and ejection accuracy that ensure high lithium recovery and waste removal with a stable and consistent performance at high capacity.

Valuable expertise and collaborative approach
The TOMRA Mining team conducted a geological assessment of sample ores supplied by Pilbara Minerals. It revealed that the pegmatite deposit did have non-lithium bearing host rock intrusions. Some of these minerals have a high density like that of spodumene, which means that it is also concentrated when using Heavy Media Separation (HMS). This reduces the efficiency of the downstream floatation and contaminates the final product. Sensor-based sorting technologies, on the other hand, can measure the colour, density, and mineralogical variations in individual particles, enabling the accurate detection and removal of this barren material.

Working closely with the Pilbara Minerals metallurgical team, TOMRA conducted extensive testwork at the TOMRA Test Center in Sydney to check all the options and answer any questions arising during the tests.

The samples were run at capacity on production sorters and included repeatability and variation testing. The test work benchmarked the expected performance of the sorters and was used to establish the sort quality on each of the ore types that will be fed through the plant.

Primero Group, which was awarded the contract for construction of the project, has now started bulk earthworks for the sorting plant.

The TOMRA team was involved not only in the testing and supply of equipment, but also provided assistance with the plant layout and understanding of the implications of sorting on the upstream mining and downstream process of the ore. This involvement throughout the development process will add to efficient operational ramp-up and technical optimization.

Ongoing support with local team and global resources – de-risking adoption of a new technology
TOMRA’s capability to support the project with a dedicated Australian-based team and a global support structure has been a significant factor and is an important part of de-risking the installation of this new technology. The team is working closely with Pilbara Minerals through the installation process, commissioning and start-up, and will continue to provide on-site support once the sorting plant is up and running.

Further information:
TOMRA
www.tomra.com/mining

TOMRA Mining has launched a new ejection module for its proven COM Tertiary XRT sorter specifically developed for sorting small particle sizes. The COM Tertiary XRT Fines sorter (Figure 1), featuring the new TS100C module and the recently introduced image processing unit, is capable of sorting particle sizes down to 4mm in high-capacity applications with much higher energy efficiency, delivering a high-quality product at low operating costs. Field tests have shown that it can deliver a 70% reduction in energy use on a production scale.

Sorting small particle sizes to add value to the process

The new high resolution TS100C ejection module (Figure 2) features a new type of ejector that is four times faster. Together with the new high performance 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.

The fast and highly precise ejection module uses significantly less compressed air to eject the particles and reduces the energy consumption dramatically. Extensive test work was conducted at the TOMRA Test Center, both with artificial material mixtures and real-world sample material. The tests showed a spectacular reduction in air consumption compared to industry standards, as well as an improvement in product purity of around 15%. With the consequent cut in operating costs, sorting small particle sizes down to 4mm with the COM Tertiary XRT Fines sorter is not only viable, but adds value to the process.

“We are receiving a rapidly growing number of requests from customers to sort smaller particles,” comments Ines Hartwig, Director Product Management at TOMRA Mining (Figure 3)). “One of the biggest drivers of cost in sensor-based sorting is the energy used for the compressed air for the ejectors. The new TS100C ejection module successfully addresses this issue and provides an effective solution to this increasing demand. It is a groundbreaking invention to create more higher-value product and reduce product loss.”

Tried and tested in industrial production

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 35mm at about 20t/h.

“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,” explains Ines Hartwig. “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 completed several trials, carefully documenting the energy savings and sorting efficiencies. The results were remarkable: 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 to 30t/h with comparable results.

Experience small particle size sorting first-hand

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. Mining operators can view the tests online or experience them first-hand at the Test Center.

Further information:
TOMRA
www.tomra.com/mining

Free-to-download publication spotlights how sorting data can now be easily accessed and understood to gain commercial advantage

TOMRA Mining has published a new eBook to help mines enhance efficiencies and profitability by using information gathered by sorting machines. The easy-to-read, 21-page booklet, titled ‘When Sorters Become Data Generating Machines’, explains how businesses can “connect to possibilities” with the TOMRA Insight data platform, and the competitive advantages this gives.

The eBook starts by reminding us that sensors in sorting machines can do a lot more than identify whether products or materials on a line should be accepted or rejected. As the book says: “They collect and store every piece of information about what they see. And this information can tell you a lot about how your machine is performing, about the products that pass through it, and your process.”

The eBook makes the encouraging point that turning TOMRA’s sorters into connected devices isn’t difficult, and businesses can benefit from digital sorting data with minimal impact – all that’s needed is wiring and a stable internet connection. The data solution’s software stores and processes the data coming from sorters and presents this in near real-time in a dashboard-style monitoring and reporting system. This is compatible with SCADA systems – but whereas SCADA controls the process and visualizes related alarms, performances, and control parameters, the digital sorting dashboard enables advanced analytics based on much larger data sets and time series.

Two types of data can be generated by sorters. Data at Rest contains non-real-time information about machines, such as service reports, spare parts history, and manuals. Data in Motion contains a continuous flow of dynamic data originating from the sorting activity, including alarms, sorting throughput, and statistics. It is the Data in Motion which becomes a powerful reporting and decision-making tool.

The eBook identifies four categories of process data. Feed composition statistics visualize what the machine sees, giving a good view of the nature and quality of the products or materials in the infeed stream. Material distribution statistics visualize the distribution of material on the machine over time, monitoring whether machines and processes are running optimally. Sorting statistics visualize the sorting fractions, serving as a powerful tool for quality management and helping to match product characteristics to customer requirements. And machine health data provides information about the machine’s operational status and condition, preventing unnecessary downtime.

This deep mine of information is accessible and actionable through TOMRA Insight, the cloud-based data platform available to TOMRA machine users as a subscription-based service. The eBook explains how digital sorting data gathered by TOMRA Insight is secure – and how, by putting this data to good use, sorting can be transformed from an operational process into a valuable strategic management tool.

‘When Sorters Become Data Generating Machines’ is downloadable here free-of-charge.

Further information
TOMRA Mining
www.tomra.com/mining

The integration of TOMRA’s ore sorting technology at the mine is a story of close collaboration between two companies that share the same philosophy: make the most of natural resources towards a circular economy. Its success is testament to TOMRA’s capacity to listen to the customer and develop tailored solutions for mining companies of all sizes – from large international concerns to small local operations with limited budgets.

Mina Esperanza de Caravelí, owned by MTP and operated by Minera Croacia, is a polymetallic gold copper vein deposit with a mining rate of 150 metric tons per day. It is located in the district of Atico, in the Nazca – Ocoña geological gold belt in the southern part of Perú, and contains narrow veins with a rosary formation, of which over 30 have been discovered so far. The mineralization is located in vein fill fractures of hydrothermal origin and mesothermal in appearance. In 2019, Minera Croacia contacted TOMRA to explore a solution to extract value from low grade ore that was being discarded for not being economically viable, and address the environmental issue of metals left in the dumps.

TOMRA and Minera Croacia share an approach to mining that recognizes the key role of mining in the transition to a circular economy. “Mining operations need to find ways to optimize the use of natural resources while reducing waste and their impact on the environment as much as possible. With TOMRA’s ore sorting technologies this is possible,” says Marco Fernandez Concha, Senior Geologist to Minera Croacia.

A close collaboration for a precisely tailored solution

Minera Croacia is a small mining company for which a sensor-based ore sorter is a significant investment: “When we purchase important equipment, we need to analyze the solution in great detail because we can’t afford to make mistakes,” explains Emilio Uribe, Senior Metallurgical Advisor at Minera Croacia. “We need it to work and deliver the results we want from the start. TOMRA has adapted to our needs as a small business with limited resources. They have been an important advisor, giving us all the support we needed with highly qualified and knowledgeable staff. They have really committed to the project and found the solution that meets our operational needs and is financially viable for us.”

The teams from TOMRA and Minera Croacia worked closely to precisely analyze the requirements and identify the best solution. TOMRA’s Test Center in Wedel, Germany conducted three series of tests on samples from the mine to narrow down the requirements. A technical team from Minera Croacia attended the final session, which gave them a better understanding of what TOMRA’s XRT technology could do for their operation.  “This project stands out for presenting different types of ores from different locations,” explains Christian Korsten, who at the time was the Test Center’s Manager. “Usually we test one or two different ores for a customer, but with Minera Croacia we had different metallogenic veins. They were all a little bit different in mineralogy, sensor response, and in the customer’s objectives for each.”

Excellent communication between the two companies’ teams was crucial to the successful outcome – especially since Covid-19 travel restrictions limited the opportunities for face-to-face meetings. Mathilde Robben, TOMRA Key Account Manager, ensured Minera Croacia received the support and advice they needed throughout the process: “We did it all through online meetings. The management team and staff at Minera Croacia were always to the point and friendly, and together we completed this fast-track project”.   Christian Korsten agrees: “Minera Croacia had very clear objectives. All our questions were answered in a perfect, fast and professional manner, and the same applies to the discussion of the test results. This project was one of my favorites in almost 10 years in the Test Center.”

TOMRA COM Tertiary XRT sorter extracts maximum value from low-grade ore

Following the detailed analysis of the test results and Minera Croacia’s requirements, Mathilde Robben proposed the TOMRA COM Tertiary XRT sorter as the solution: a machine perfect for the particle size range of the dump material (-25mm / + 10mm and -40mm / + 25 mm) and an investment that fits Minera Croacia’s budget

The test results made a clear business case for the sorter. They showed that for 1300 tons of Run of Mine material containing gold and copper, 21% are fines (-10mm) and screened out. This results into a concentration of gold and copper in the fines and therefore, this material does not need to be sorted. Of the rest of the material, 34% is enriched, going from a grade of 2.7 g/t Au Eq. to 5.12g/t Au Eq. – almost double.

This leaves 45% of the material discarded as waste with very low metal content, 0.41g/t Au Eq., which addresses the environmental issue, as it contains virtually no contaminants. This also shows that maximum value has been extracted from the material, as there is virtually no gold left.

“The test has shown that TOMRA’s sorter can create value from material that would have gone to the waste dump, from 33% of the ROM that is too low-grade for processing to be financially viable,” says Emilio Uribe, very satisfied with the results.

The TOMRA COM Tertiary XRT sorter is now installed and operating since December 2021 re-processing the mine’s 800,000 tons of historic dumps. It is delivering on all counts for Minera Croacia: it is now able to increase the grade of the dump material that was not considered economic, it has reduced freight costs of the operation as it is now transporting less low grade material to its processing plant, and it has successfully addressed the environmental impact of its waste materials.

“All the calculations we made when we evaluated this investment are being fulfilled. The sorter’s performance is perfectly consistent with the test results, and we expect it to pay for itself as planned within two years – including the other components and infrastructure of the circuit,” concludes Emilio Uribe.

The company’s management is so impressed with the results achieved, that it is considering investing in further sorters for low grade  ROM ore with the aim of extracting value from mineral that is currently considered marginal.

Further information:
TOMRA Minig
www.tomra.com/mining

TOMRA Mining provides effective solution for the extreme conditions at the Bluestone Mines Tasmania JV (BMTJV) Renison tin mine in Tasmania (Figure 1), with its XRT sensor-based sorting technology unlocking significant value and delivering environmental benefits.

The Renison mine is 50% owned by Metals X through the Bluestone Mines Tasmania Joint Venture (BMTJV). It is the only major tin project in production in Australia with a mining rate of close to 1Mtpa, although the concentrator is restricted at 750,000tpa. The extreme humidity, with an annual rainfall of over 3,000 mm, and the highly acidic processing water with pH around 4.5, creates unique challenges for the sorting process, the equipment, and waste management, which BMTJV resolved with TOMRA’s help.

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 3-stage crushing, screening and cleaning. The particles are split into two fractions – 10 to 25mm and 25 to 60mm – which are fed into two TOMRA X-Ray Transmission (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.

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. The first was the need to upgrade their tin feed to the plant: “The Renison Tin operation wanted to achieve economies of scale, putting more tons through the front end of the plant without upgrading the back end downstream – we wanted to do more with less,” explains Ben Wraith, Principal Project Metallurgist at BMTJV (Figure 2). 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 (Figure 3) and the waste issue with a COM Tertiary EM 1200 sorter.

A team from BMTJV visited the TOMRA Test Center in Sydney, where they observed what the XRT sorter operating at capacity is capable of and experienced first-hand the exceptional accuracy of TOMRA’s XRT sensor. “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,” says Gavin Rech, Technical Manager at TOMRA (Figure 4). “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.”

TOMRA XRT sorters: the right solution for Renison’s specific conditions

The two COM Tertiary XRT 1200 sorters went into operation in 2018. Initially, BMTJV’s strategy focused on low reject grades, devoting less attention 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 ore delivered from underground, further affected the sorting process.

In 2019, a new investigation was opened into the ore sorting performance and led to a change of direction: “a paradigm shift away from targeting low reject grades, towards sorting as aggressively as possible, moving from a tin recovery-based operating strategy to a mass reduction one,” explains Ben Wraith. “We are getting 20 to 25% mass reduction, so 75 to 80% of the materials are going into the wet plant, and we are still achieving 97 to 98% tin recovery overall across the crushing circuit. 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 is best for Bluestone’s application: this configuration gives us the ability to process 15 to 20% more tin units without having to upgrade the downstream concentrator.”

TOMRA’s XRT sorters have proved to be a sound investment that is delivering significant returns: “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 to 20%, and thus tin production, so the unit cost per ton of tin produced is reduced by almost 10%,” says Ben Wraith. They have shown to perform consistently, giving BMTJV the confidence in forecasting: “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: “the decision to buy new machines was easy,” says Ben Wraith. “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.”

Ben Wraith is particularly looking forward to TOMRA Insight: “It will enhance everybody’s understanding and experience of the machines. It will be more of an analytical platform for our metallurgy and maintenance staff, providing ample opportunity to gain valuable information that can be analyzed and optimized over time. The one feature I am personally interested in 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 that their technical teams will be well prepared ahead of site visits for maintenance or optimization.

A close collaboration to achieve the best results

Throughout the process, BMTJV worked closely with TOMRA. “TOMRA has been working with the site maintenance team to tailor solutions to our operating environment, which has been invaluable,” says Ben Wraith “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 fine tune it to our site-specific requirements. They assisted the site with troubleshooting, optimization, discussing the nuts and bolts of the issues as they arose and finding a solution that works.”

Further informations:
TOMRA Minig
www.tomra.com/mining

TOMRA’S XRT sensor-based sorting technology unlocks significant value for Gem Diamonds at its Letšeng Diamond Mine. It delivered an effective solution for coarse fractions in historical tailings dumps, recovering 15 times the initial investment in four years. This success has led to the installation of the first TOMRA final recovery sorter in the world, now in its final commissioning stage. Projects to further upgrade the mine’s recovery plant with more TOMRA XRT sorters are in the pipeline.

Gem Diamonds, a leading global diamond producer of large high value diamonds, owns 70 % of the Letšeng mine, located in the Maluti Mountains of Lesotho (Figure 1). It is one of the largest open pit diamond mines in the world, it processes ore from two kimberlite pipes – the Main pipe (17.0 ha) and the Satellite pipe (5.2 ha) – and is known for the recovery of Type II diamonds. The ore is treated through two plants with conventional crushing, scrubbing, screening and Dense Medium Separation (DMS) processes. The DMS concentrate is split into three fractions that are sent to be processed with XRT (X-Ray Transmission) and XRF (X-Ray Fluorescence) technologies.

In 2017, the company undertook several activities to unlock the mine’s full potential and contacted TOMRA Mining, Wedel/Germany, to explore ways of improving its coarse recovery process.

Jaco Houman, Senior Manager Technical and Projects at Gem Diamond Technical Services, explains: “We had quite a lot of historic tailings material. We had a view that, since we had commissioned a new coarse recovery in 2015, we weren’t quite getting all the diamonds we were looking for. We worked with our supplier to improve, but we felt we had reached a ceiling point. That’s when we decided to augment the installed base and contacted TOMRA.”

Gem Diamonds rented a TOMRA COM Tertiary XRT sorter, which was deployed in the second half of 2017 to process historic tailings. The initiative was a success and the TOMRA sorter delivered on all the objectives Gem Diamonds had set: “During the six month rental of this unit, we got a better understanding of our primary recovery efficiencies, we were able to conduct off-line auditing and scavenging activities, we increased our diamond recovery and revenue, and we effectively introduced bulk treatment of historical recovery tailings”, Houman explains. TOMRA’s XRT sorter exceeded all expectations: “The unit showed that it recovers consistently from the tailings material. The value that came from it spoke volumes about the technology and the potential that could still be obtained with the material available. It cemented the realisation that we needed a recovery unit for scavenging, auditing and second-pass recovery.”

On the back of the excellent results achieved with the rental unit, Gem Diamonds purchased a TOMRA COM XRT 2.0 (Figure 2) sorter to replace the rental unit at the end of the contract. Featuring a bigger ejection chamber, higher belt speed and throughput, this unit was perfectly suited to the large diamond recovery set up the company was looking for, and they didn’t have to wait for it to deliver:

“In January 2018, we had pretty much just finished commissioning this unit and we recovered the biggest stone Letšeng had ever seen, the 910 ct Lesotho Legend. There was no question about performance after that,” says Houman. “Since 2017, we have recovered six diamonds that were sold for more than 1 M US$ with the two TOMRA XRT sorters.”

Since installing the TOMRA COM XRT 2.0, the mine’s +5 mm historic material has been depleted and the company is now focusing on scavenging and auditing the existent tailings. Houman explains: “About 10 t/d of coarse fractions are stockpiled per export period, and we do roughly eight exports a year. Over an average of about 45 d, we accumulate 450 to 500 t, which we process at the end of the export period. We are seeking confirmation that all economical value has been recovered and that nothing has been missed in our recovery process. By having this unit in place, we are now able to recover all the diamonds that are present in our concentrate, either through a first or a second pass.”

With its performance, the TOMRA COM XRT 2.0 sorter has more than paid for itself, as Jaco Houman points out: “To date, we have recovered about 15 times the investment value over the four years it has been in operation.”

Gem Diamonds has been so impressed with TOMRA’s XRT technology that they have become early adopters of its ground-breaking final recovery solution, purchasing a TOMRA COM XRT 300 /FR sorter before it was even launched, so that the Letšeng mine is home to the first unit to be installed in the world.

Having found an effective solution for coarse recovery with the TOMRA COM XRT 2.0 sorter, Gem Diamonds turned their attention to the fines recovery circuit. “We sent some samples for testing to an independent facility and our assumptions of under-recovery in certain size fractions were confirmed,” says Houman. “We wanted to find a solution to increase our revenue from the treatment of historic material. We were looking for a compact machine we could use as a final recovery sorter, and the TOMRA COM XRT 300 /FR performs very well in that duty, or even as a single particle sorter. Also, it is a sorter that will treat a super-concentrate and work very well as a scavenging unit.”

“The diamond industry had been waiting for 20 years for a way to introduce XRT directly into the diamond final recovery instead of the bulk concentration stages where the DMS modules exist,” explains Ryan Szabo, Sales and Project Manager Diamonds at TOMRA. “The TOMRA COM XRT 300 /FR is a compact sorter that can function within the diamond recovery and sort house environment, and it is the first to accurately sort diamonds based on their properties and not their proxies, achieving market leading recovery with the highest recovery factor to date. This made it ideal for Gem Diamonds’ requirements at the Letšeng mine.”

TOMRA’s final recovery sorter is now in the commissioning stage, and performing well, as Houman states: “We are getting consistent recovery from the TOMRA COM XRT 300 /FR, which is performing to our expectations from this perspective. The overall throughput has not been attained due to deficiencies in the drying system upstream, which are making feeding the sorter at higher throughput rates difficult. However, design corrections are in the process of being implemented and I am confident that we will be able to demonstrate performance of the final recovery sorter at the higher capacities.”

The installation of the TOMRA COM XRT 300 /FR is the first in a series of three projects that Gem Diamonds is planning in order to upgrade its recovery plant with the addition of further TOMRA XRT sorters. The company is also working on a project for the construction of a second recovery circuit that would combine the TOMRA COM XRT 2.0 sorter currently on site, a new TOMRA COM Tertiary sorter and a COM XRT 300 /FR sorter to create an off-line scavenging facility. This will be followed by a third project, which will look at implementing TOMRA XRT technology through the remainder of the final recovery.

The last four years have seen the successful introduction of TOMRA’s XRT technology at the Letšeng Diamond Mine, where it has provided effective solutions in different stages of the process, improving the operation’s profitability and efficiency. For Houman, this success stems not only from the advanced technology, but also from TOMRA’s approach to serving its customers: “What I like about TOMRA, is that for them it’s not just about selling you a piece of equipment. If the equipment doesn’t work in the solution or the system that you want, they’d walk away from the sale. For me, this testifies to the fact that they have a vested interest in the success of your business.”

Further information:
TOMRA Sorting Mining
www.tomra.com/mining