Tag Archives: TOMRA

Metso Outotec on ore sorting’s potential ‘revolutionary change’

Metso Outotec stands out among the mining original equipment manufacturers for having publicly acknowledged ore sorting is on its radar.

The Outotec business had a relationship with TOMRA Sorting Solutions dating back to 2014 when the two companies signed an agreement that would see the particle sorting company supply Outotec-branded sorting solutions to the mining and metallurgical industry. Metso, meanwhile, has previously disclosed it was developing “breakthrough proprietary technology to address the demand of high throughput accurate sorting”.

Close to eight months after the two companies merged to become Metso Outotec, IM put some questions to Erwin Huber, Vice President, Crushing and Conveying Systems; David Di Sandro, Business Development Manager – Optimisation and Test Labs; and Rashmi Kasat, VP, Digital Technologies, Minerals, to find out the current state of play with ore sorting at the mineral processing major.

IM: Back in November at your Capital Markets Day, there was mention of ‘AI-powered Ore Sorting Solutions’ during a presentation. Can you expand on what this offering might include? What stage is it at in terms of commercialisation?

DDS: Ore sorting is one of the most exciting recent developments in our industry. With improvements in sensor capabilities and adoption of artificial intelligence (AI), this may well become the revolutionary change this industry needs to sustain itself in the face of diminishing grades and orebody quality.

EH: With our ore sorting solution development, we are targeting the ability to deliver complete offerings of hardware and sensor-fusion platforms as it relates to both bulk and particle ore sorting. These platforms would utilise AI to optimise the feed material for the downstream process. Metso Outotec is uniquely positioned to understand and optimise that plant feed stream with deep knowledge and almost complete technology coverage in both the concentrator and tailings processing areas.

We plan to bring new solutions to the market in the short term and continuously launch new technologies to increase capabilities and capacities when the developments are mature enough.

IM: Will these solutions leverage existing tools within the Metso Outotec product offering? Will they make use of existing agreements with other companies (for instance, the agreement with TOMRA that Outotec previously had in place)?

EH: Metso Outotec carries out its own development of these solutions, and some partnerships are part of it once sensoring and analysing different minerals and elements are not possible with a single or only a few technologies. Mining and concentration are becoming more and more a digital world where breakthrough innovation is finding its space towards efficiency and sustainable possibilities. Smart systems will enable improved equipment uptime, efficiency and remote diagnosis of process and maintenance, and will be the bonding element between our traditional offering portfolio and new technologies.

IM: Previously Metso has talked about the development of a bulk sorting solution: do these ‘AI-powered Ore Sorting Solutions’ fit into that category, or are they more particle sorting solutions?

EH: Bulk ore sorting enables material selection at high throughput flows and particle technology is limited by capacity while bringing the benefit of high accuracy on selectivity.

RK: Bulk sorting is in its early stages in industry and no single sensor can determine minerals content across all ore types and mine sites. This is where AI algorithms play a significant role in ‘self-learning’ ore characteristics, mine site by mine site. It also provides great opportunities to do sensor fusion and more accurately determine the minerals content based on outputs from various sensors and sensor types. AI augments our expert’s tacit knowledge and provides a more reliable way over time to analyse big data generated from online mineral analysis.

IM: Where in the flowsheet do you envisage these solutions going?

EH: The earlier we can remove the gangue from the flow stream, the better our energy efficiency will be by reducing the volume of waste material that is processed by downstream equipment. Deposits in advanced development allow for in-pit backfill bulk ore sorters that may be deployed behind mobile in-pit crushers, or before the coarse ore stockpile where backfilling is not an option. There are several pre-concentration technologies that can be applied at each stage of mineral processing and the ideal operation should combine those tools to remove the liberated gangue at multiple stages of the processing plant in order to achieve the most sustainable process (ie bulk/particle ore sorting, selective breakage, coarse flotation).

IM: Will the benefits of your solution be felt beyond the crushing and grinding stage? Do you intend to use the data generated from the ore sorting solutions to benefit the whole downstream flowsheet?

DDS: One of the benefits of ore sorting is more efficient removal of waste from the process feed. Under certain circumstances, this also means removal of deleterious material which otherwise would adversely affect downstream process performance such as flotation recoveries. In these cases, the downstream benefits are intrinsic. The key would be understanding the geometallurgical mapping of all rock types and their mineralogy, so a philosophy of ‘include or reject’ can be applied on a metallurgical response basis. This mapping can be improved with SmartTag™ and GeoMetso™ technologies from Metso Outotec.

EH: The ability to sort, the geometallurgical mapping and metallurgical response obviously feed back into the block model and allow for more options in the mine plan and life of mine resource recovery, for example with the deployment of low-grade stockpiles. This further enhances the sustainability of the mining operation.

IM: Is the market ready for and receptive to such a powerful ore sorting solution?

DDS: As we all know, for good reason, our industry is full of early adopters rather than innovators. Most operations will need to see the technology succeed elsewhere before increasing their uptake of the technology. The initial implementation will likely occur in partnership with customers whose operations need this technology to be economically viable.

EH: The key is to understand the ore variability through the deposit and through the life of mine. Adopting ore sorting as an integrated processing step does not differ that much from testing and sizing flotation circuits, where small changes in ore properties can affect the overall recovery. It is important to understand these changes and how to react to them during operations.

The confidence level in sensor-based ore sorting testing will grow over time. We already see real-life examples where customers report on ore reserves based on lower cutoff grades due to ore sorting.

IM: Anything else to add?

EH: Despite the fact that the concept of ore sorting, and the sensors required to detect the valuable ore from the waste, have existed for several years, if not decades, the implementation of these systems in full-scale operations have been relatively restricted to particular cases with the right kind of orebody to make the process viable. Implementing ore sorting more broadly remains the challenge and requires the dual application of the right sensors working effectively with the right mechanical handling systems to detect and remove the waste stream efficiently and accurately. The skills required to solve these challenges are not just for the traditional mining and mineral processing engineers, but need to include a cross-disciplinary team addressing the issues from all angles.

This Q&A interview was carried out as part of the IM March 2021 annual ore sorting feature, to be published early next month

Hochschild’s Inmaculada set for ore sorting pilot plant

Hochschild says it has approved a $7 million budget to construct an ore sorting pilot plant at its Inmaculada gold mine in Peru in 2021.

The investment follows previous test work carried out with both TOMRA and Steinert. This saw the company conduct initial bulk testing in Germany with both companies and a 20-t pilot scale test with Steinert in Brazil.

The company also enlisted the help of Ausenco to carry out a prefeasibility study on applying ore sorting at Inmaculada.

In the company’s 2019 preliminary results presentation back in February, Ramón Barúa, Hochschild Mining Chief Financial Officer, said ore sorting could prove particularly useful at the Millet and Divina veins at Inmaculada.

He said, in addition to consulting with TOMRA, Steinert and Ausenco, the company had been working in-house to improve the sensors and the algorithm that separates the ore from the waste in these sorters, with the technology showing a clean separation between the quartz-based mineralisation and the andesite holding the rock at Inmaculada.

In its latest financial year results released today, Hochschild said of the ore sorting investment: “We believe this project may eventually deliver significant improvements in recoveries at the mine and potentially help to optimise other key projects in Hochschild’s portfolio.”

For 2020, the company recorded overall production of 289,293 oz of gold-equivalent at an all-in sustaining cost of $1,098/oz of gold equivalent. Inmaculada remained the cornerstone of the company, producing 176,086 oz of gold-equivalent.

Peel Mining’s South Cobar preliminary flowsheet to factor in ore sorting

Peel Mining says positive results from ore sorting test work at the Southern Nights and Mallee Bull deposits, part of its 100%-owned South Cobar Project, in western New South Wales, Australia, provide encouragement for the inclusion of this pre-concentration technology into future process plant design.

So encouraged by this testing is Peel that it has engaged GR Engineering to integrate ore sorting technology into an updated processing plant technical report for the project.

At the same time as this, Peel announced that GR Engineering had recently completed a preliminary process plant technical report for South Cobar that considers crushing, grinding, gravity, flotation and cyanidation process stages for the recovery of gold, silver, copper, lead and zinc from the various mineralisation styles within Peel’s deposits.

Meanwhile, the recently received positive preliminary ore sorting test work results from work undertaken on diamond drilling samples shows there is potential for improvements in the flowsheet.

The ore sorting test work, completed in conjunction with ongoing metallurgical studies, was undertaken by Steinert and TOMRA.

Steinert ’s test work on Southern Nights mineralisation demonstrated strong recovery and upgrade potential with two size range samples returning, on average, circa-93% Zn, circa-91% Pb, circa-91% Ag, circa-87% Cu and circa-82% Au recoveries to an average of circa-54% of the feed mass (circa-46% of feed mass rejection) increasing the lead and zinc grades by 61% and 64%, respectively.

TOMRA’s test work on Mallee Bull mineralisation achieved significant waste mass reductions while maintaining very high copper recoveries (≥95% for the higher-grade breccia copper and massive sulphide copper samples), the company said. A lower grade breccia copper sample upgraded from 0.59% Cu to 1.05% Cu with 77% Cu recovery and 56% mass rejection, it noted.

“Positive results from ore sorting at Southern Nights and Mallee Bull deposits provide encouragement for the inclusion of this pre-concentration technology into future process plant design and, as a result, Peel has engaged GR Engineering to integrate ore sorting technology into an updated processing plant technical report,” the company said.

Peel’s Executive Director of Mining, Jim Simpson, said: “The completion of the processing plant technical report by mineral processing solutions experts GR Engineering is a critical first step in understanding the potential composition of the milling infrastructure required for the company’s development plans.

“The detail presented in the report by GR is impressive and the report will form the basis for ongoing preliminary studies for the refinement and improvement of the processing plant design as new information comes to hand.

“We are also very pleased with the potential of ore sorting as part of any future South Cobar project hub’s processing route with initial test work pointing to the amenability of both Southern Nights and Mallee Bull mineralisation to separation using 3D-XRT ore-sorting technology, allowing for the simultaneous rejection of barren or waste material whilst retaining the bulk of contained metal, and in the process, upgrading the value of the ore.”

Simpson added: “Apart from reducing the overall feed mass by the rejection of waste at early stage, other benefits of ore sorting include potentially upgrading lower-grade mineralisation and reducing the size of the processing plant offering potentially reduced capital, power, water and tailings storage needs.”

Lucara recovers second plus-300 ct diamond of 2021 at Karowe mine

Lucara Diamond Corp has announced another recovery of significance from its 100% owned Karowe Mine, in Botswana, with its TOMRA X-ray Transmission (XRT) sensor-based ore sorting units, again, helping the miner recover and keep the diamond intact.

A magnificent unbroken Type IIa 378 ct gem quality top white diamond was recently recovered from milling of ore sourced from the M/PK(S) unit of the South Lobe, Lucara reported. This recovery is the second plus-300 ct gem quality diamond to be recovered this year from direct milling of the M/PK(S) unit, a further testament to the strong resource and process circuit performance at Karowe, the company said.

Both the 378 ct and the 341 ct diamonds recovered this year came from the Coarse XRT circuit, Lucara said.

Eira Thomas, Lucara’s CEO, said: “The 378 ct joins a rare and special lineage of exceptional, high value diamonds recovered at Karowe and continues to highlight the wonderful diamond potential of Botswana. Continued and consistent recovery of large diamonds, such as the 378 ct and 341 ct stones, comes at a critical time and provides continued strength and additional foundation to the opportunity to finance and build the underground expansion at Karowe that will see mining continue for at least another 13 years after the open pit ceases operations in 2026.

“We look forward to a safe, productive and busy 2021.”

A 2019 feasibility study looking at a combined open pit and underground future at Karowe showed the company could double the mine life of the operation for $514 million in pre-production capital by developing an underground deposit.

TOMRA XRT units help recover unbroken 998 ct diamond at Lucara’s Karowe mine

TOMRA’s COM XRT 2.0/1200 ore sorters have aided Lucara Diamond’s Karowe diamond operations, in Botswana, once again, recovering an unbroken 998 ct high white clivage diamond from the 100%-owned mine.

The diamond, measuring 67 x 49 x 45 mm, was recovered from direct milling of ore sourced from the EM/PK(S) unit of the South Lobe, and follows a series of significant diamond recoveries during this recent production run, including several top quality clivage and gem-quality stones of 273 ct, 105 ct, 83 ct, 73 ct, and 69 ct in weight.

“The EM/PK(S) forms an important economic driver for the proposed underground mine at Karowe and continues to produce large gem-quality diamonds in line with expectations, a further testament to the strong resource performance at Karowe,” the company said.

Last year, a feasibility study showed the company could double the mine life of Karowe by establishing an underground mine for $514 million in pre-production capital.

The 998 ct diamond (pictured) was recovered in the MDR (Mega Diamond Recovery) XRT circuit that allows for diamond recovery post primary crushing and prior to milling. The MDR circuit has, in the past, treated material in the size range between 50-120 mm. This latest recovery represents the second plus-500 ct diamond recovered from this circuit in 2020, Lucara noted.

Year to date, Karowe has produced 31 diamonds greater than 100 ct, including 10 diamonds greater than 200 ct comprising of the 549 ct Sethunya, and the 998 ct diamond.

Eira Thomas, Lucara CEO, said: “Lucara is extremely pleased with the continued recovery of large high-quality diamonds from the South Lobe of the Karowe mine. To recover two plus-500 ct diamonds in 10 months along with the many other high-quality diamonds across all the size ranges is a testament to the unique aspect of the resource at Karowe and the mine’s ability to recover these large and rare diamonds.

“Operations at Karowe have continued through 2020 and operational challenges, due to COVID-19 restrictions, have been met with professionalism by the team. We look forward to a safe finish to 2020 and continued success at Karowe as we remain focussed on strong operations to ensure maximum resource performance.”

TOMRA connects ore sorters to the cloud with TOMRA Insight

After a successful launch in its recycling division, TOMRA is rolling out its cloud-based data platform, TOMRA Insight, to mining customers.

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

Following a successful launch last year by TOMRA Sorting Recycling, TOMRA is now also being made available to customers of TOMRA Mining and TOMRA Food. For all three industries, the platform is enhanced by new features and functionalities that make TOMRA Insight even more valuable than when it was launched to recyclers in March 2019.

The data from TOMRA Insight is gathered in near real time, stored securely in the cloud, and can be accessed from anywhere and across plants via a web portal available for desktop and mobile devices, according to the company.

Felix Flemming, Vice President and Head of Digital at TOMRA Sorting, said: “By capturing and using valuable data, TOMRA Insight is transforming sorting from an operational process into a strategic management tool. This tool is constantly becoming more powerful as we continuously develop it in response to customers’ needs and priorities. New functionalities and features are released every three weeks – a routine during which TOMRA works closely with customers in pursuit of shared objectives.”

Data captured by TOMRA Insight provides valuable performance metrics that help businesses optimise machine performance.

Operating costs are reduced by simplifying spare part ordering and offering flexible access to data and documentation, according to the company. Downtime is reduced by monitoring machine health and performance in near real time, identifying gaps in production and analysing potential root causes. This allows management to move to predictive and condition-based maintenance, preventing unscheduled machine shutdowns.

Throughput, meanwhile, is maximised by evaluating variations and optimising sorting equipment, accordingly. Sorting to target quality is enhanced by having accurate material composition data to enable decisions to be based on more detailed information.

For the mining and mineral processing industries, TOMRA Insight’s ability to collect detailed data from TOMRA’s sorting machines means that previously hidden information can lead to improvements in efficiencies and profitability.

Data captured by TOMRA Insight is analysed on behalf of customers by TOMRA Mining engineers, and key findings shared in confidential reports supplied to customers on a monthly basis. This arrangement has the advantage of combining objective statistical analysis with the interpretive skills of a service team familiar with the customer’s unique challenges, TOMRA says.

“TOMRA Insight’s data-gathering helps mineral processors in near real time and in retrospect,” the company said. “Machine operators are empowered to take prompt action in response to changes in material composition on the line and managers are empowered to make operational and business decisions based on more complete information.”

Comparisons between multiple sites or lines can now be made more accurately and difficult-to-reach processing operations can be remotely monitored from more convenient locations, the company said. This functionality is especially useful in the face of widespread travel restrictions related to COVID-19.

One early, pre-launch user of TOMRA Insight is the Black chrome mine in South Africa (pictured above), one of two mining projects that form the basis of the Sail Group’s plans for long-term sustainable chrome production. Since TOMRA Insight was connected to sorting machines here at the start of 2020, the data platform has convincingly proven its effectiveness, TOMRA said. Among the gains made so far are improvements in process monitoring and streamlining, more efficient line-feeding and machine running times, and reduced downtime.

Albert du Preez, Senior Vice President and Head of TOMRA Mining, said: “By accessing information, TOMRA Insight is unlocking new opportunities. Mineral processors can now move from making decisions based on experience and local observations to decisions based on experience and hard facts. This means TOMRA Insight can help reduce waste rock and downstream processing costs, enabling processors to earn more dollars per tonne.”

To build on these benefits, TOMRA Mining is working closely with customers to continuously develop TOMRA Insight. The future will bring the addition of more features and functionalities, which customers will automatically receive as part of their Service Level Agreement.

TOMRA makes recovery promise to diamond miners

TOMRA is offering diamond mining customers a guaranteed diamond recovery of greater than 98% with the use of its sensor-based ore sorting technology.

The company is making this guarantee alongside a promise of 100% detection in the specified range, irrespective of luminescence profile or coating.

As the company says, maximising diamond recovery while optimising costs is the top priority for every diamond producer.

“With TOMRA’s holistic approach and cutting-edge technologies, both can be achieved to deliver outstanding results,” it said, adding that its X-ray Transmission (XRT) diamond recovery technology has helped recover some of the largest and rarest gemstones in history.

TOMRA says it approaches every project as a partnership with the customer to deliver a complete solution that meets their operational and business requirements.

This begins with a detailed analysis of the customer’s requirements and operational needs.

TOMRA – Operations Hub Johannesburg

Working collaboratively, it assists in developing a tailor-made flowsheet redesign that combines its XRT technology with its Near Infrared (NIR) and Laser solutions as needed. This collaborative approach continues throughout the project, with testing at its Test Center in Germany and, on-site, as required, through to installation and beyond.

More recently, this approach has been enhanced with the development of a remote testing option.

“The complete solution can also include the web-based TOMRA Insight platform that turns all the sorters into connected devices for monitoring and tracking the system’s performance,” the company said.

Once the system is fully operational, TOMRA offers its Service Level Agreement to ensure its solution continues to deliver the desired results.

“The tailored agreement can include on-site presence as required, seven days a week product support, application engineer visits, tiered urgency support, targeted site response, training, as well as spare and wear parts coverage to ensure maximum uptime and protect the customer’s investment,” the company said.

Advanced technologies adding value

TOMRA’s XRT technology recognises and separates material based on its specific atomic density. It uses a cutting-edge X-ray camera with DUOLINE® sensor technology to measure spectral absorption information.

TOMRA’s proprietary high-speed X-ray processing unit uses the data to produce a detailed “density image” of the material. The result is a high level of purity in sorting materials, irrespective of size, the degree of moisture or surface pollution present, TOMRA says. This makes TOMRA’s XRT high-capacity sorters effective in the recovery of free, liberated diamonds at high feed rates up to 300 t/h.

TOMRA’s NIR sorters recognise and separate kimberlite and waste rock based on their chemical composition. This technology is useful in upgrading lower grade run of mine and stockpiles, producing a kimberlite concentrate for further processing, the company says.

Marie-Claude Hallé had first-hand experience of how TOMRA’s solutions can add value to diamond mining operations when she held the role as Marketing Operations Manager for diamond exploration and producing company, Stornoway Diamonds.

“You have to really envision that TOMRA has actually changed the game in terms rough diamond recovered around the world and allowed producers to access large exceptional quality goods that perhaps in the past would be crushed to pieces,” Hallé said.

Customised solutions for kimberlite, lamproite and alluvial applications

With its customised approach, TOMRA says it can deliver on its promise of guaranteed results both in hard-rock kimberlite/lamproite and alluvial deposits – each of which presents their specific challenges.

In kimberlite, the challenge is to recover “needle in a haystack” diamonds, which requires controlled crushing of kimberlite ore to avoid damaging or breaking the diamonds, the company says.

“High waste dilution impacts the crushing energy needed and further increases diamond breakage risk,” TOMRA says. “Utilising TOMRA NIR technologies, we can remove non-diamond bearing material, not only improving the crushing profile of the ore, but also increasing the value of each tonne of ore processed. TOMRA NIR waste sorting technology can make diluted marginal kimberlite deposits economic.”

Additionally, complex, energy- and water-intensive kimberlite liberation processes, and the cost of transportation for crushing and processing, are challenges facing modern diamond miners today.

“TOMRA’s XRT and NIR technologies, which offer extremely high concentration factors, allow the production of hand sortable, ultra-high grade concentrates in as little as two stages compared to up to seven in traditional methods,” the company claims.

The challenge of economically mining low-grade alluvial deposits is due to their typically lower grade and the sporadic nature of the deposits.

The high recovery performance of TOMRA’s XRT technology enables single-stage or double-stage diamond recovery, offering a drastically lower operating cost and capital investment so that mining marginal deposits becomes economically viable, according to TOMRA.

“Another advantage of TOMRA’s XRT solution is that it can operate as a dry process, which dramatically reduces its environmental impact and operational complexity,” it says. “Besides, it opens the door to new opportunities, making it possible to mine deposits in arid areas where water access is minimal.”

TOMRA XRT machines have proved effective in alluvial operations, the company says.

One such case is that of the Lulo mine in Angola, operated by Lucapa Diamonds, where TOMRA XRT technology is used to process material between 18 and 55 mm in size and allows the recovery of diamonds of up to 1,100 ct – and where it has recovered Angola’s second-biggest diamond on record, a 227 ct stone in 2017.

Stephen Wetherall, Lucapa Diamonds Managing Director at the time of the recovery, said: “The recovery of the 227 ct diamond using the new XRT circuit justifies our investment in TOMRA’s large diamond recovery technology, which has more than paid for itself with the recovery of this one stone alone.”

Optimised flowsheet

TOMRA is in the unique position of being able to offer diamond operations a full XRT recovery flow sheet to 2 mm that delivers concentration factors up to 1 million with a much-reduced number of concentration stages, it says.

Geoffrey Madderson, Diamond Segment Manager for TOMRA Sorting Mining, explains: “TOMRA XRT technology replaces multiple stages of diamond concentration by virtue of its ability to concentrate diamonds to a hand sortable product after only a single step. This concentration factor allows for the removal of multiple recovery steps, drastically reducing both the capital investment and operational costs to recover diamonds.”

Geoffrey Madderson, Diamond Segment Manager for TOMRA Sorting Mining

TOMRA’s XRT technology can replace traditional methods such as dense media separation (DMS), wet magnetic separation and XRL final recovery with single-stage solutions for +8 mm and double-pass for -8 mm +4 mm particles, it claims.

“TOMRA’s solution eliminates up to seven concentration stages, dramatically reducing the complexity of the supporting plant and infrastructure,” the company says. “This results in significantly lower power and water consumption, which not only reduces costs, but also the environmental impact of the recovery process.”

An additional benefit of TOMRA’s solution is that it is a fully automated process, so there is no manual handling during pre-concentration and recovery, which has positive implications on security and eliminates human error, resulting in greater accuracy, the company says.

Recoveries

TOMRA’s sorters process these volumes with great efficiency, finding more diamonds than other, traditional separation methods – including coated and low- or non-luminescent diamonds, the company says.

The performance of its XRT sorters is independent of the “heavies” content in the feed, and is ideal for processing high-yielding ores unsuitable for DMS. The result is an exceptionally high recovery rate, it claims.

“TOMRA guarantees >98% recovery: that is how confident we are in our technology,” Madderson states.

With TOMRA’s sorting solutions, diamond producers can install large diamond recovery systems with a small capital investment and operate with a fraction of operating expenditures per tonne compared with traditional recovery methods such as DMS and XRL, it claims. In addition, the economic recovery of ultra low-frequency exceptional diamonds of +32 mm is now possible.

“TOMRA’s ability to deliver not only a technology that can detect such large diamonds, but also an economical process solution for the recovery of ultra-rare, exceptional diamonds is what sets it apart from its competitors,” Madderson said.

“This is the reason that, to date, TOMRA XRT has become synonymous with the recovery of extraordinary diamonds from all around the world.”

AEX Gold has high ore sorting hopes following TOMRA Nalunaq tests

Greenland-focused AEX Gold may have found an effective way to distinguish between high-grade gold-containing quartz veins and host amphibolite at its Nalunaq gold project after testing with a TOMRA ore sorting machine produced positive results.

A 500 kg bulk sample of mineralised Main Vein (MV) material, collected from the historical underground workings at Nalunaq, was used for a preliminary performance test at TOMRA’s test facility in Wedel, Germany, with the performance test report confirming that Nalunaq’s mineralised material is “highly amenable” to ore sorting technology, according to AEX Gold.

Laser sorting technology showed favourable results in the preliminary performance test, with total gold recovery ranging between 90.2% and 99.4% and with mass rejections of waste ranging from 58-62% of the incoming feed stream, the company said.

While a second test, planned for 2021, will focus on optimising the detection parameters to increase confidence in gold recovery, AEX already believes ore sorting technology, once optimised, could offer a cost-effective processing solution to supplement the company’s existing plans.

Nalunaq is a past-producing underground mine located in south Greenland. Having produced around 350,000 oz of gold between 2004 and 2009, it has demonstrated a low-cost production potential from past operations, the company says.

Redevelopment plans include developing a mining camp and ancillary facilities to establish a regional hub; carrying out 2,000 m of underground drifts into mineralisation with long hole stoping, operated by a contractor; locating a 300 t/d crushing, milling and gravity recovery plant (65-70% Au recovery) outside of the mine to provide operating scalability and store tailings for future re-processing; refurbishing an existing, permitted leaching plant, located underground, to increase gold recoveries to 95% once free cash flow positive; and adopting new technologies to improve recovery, reduce dilution, and minimise processing costs.

Eldur Olafsson, CEO of AEX, said: “Ore sorting has the potential to be a cost-effective solution for processing Nalunaq’s mineralised material. We are pleased to continue progressing on the development of the Nalunaq project by involving industrial cutting-edge technologies in our development strategies.”

Gold at Nalunaq is mineralised in a MV, which averages 0.7 m in width and exhibits a typical ‘nugget effect’. Past mining operators have used a combination of selective resue mining and conventional long hole stoping, which resulted in an average true mining width of 1.2 m, according to the company.

“Therefore, the mined material includes a significant quantity of amphibolite host rock (devoid of gold and considered as dilution),” the company said. “It is anticipated that ore sorting could be effective at Nalunaq due to the contrast in density and colour between the high-grade gold-containing quartz veins (white) and host amphibolite (dark grey).”

Filling the mineral processing flowsheet gaps

Crushing, grinding, flotation, solvent extraction, electro winning, tailings management…Metso Outotec covers it all.

The new mineral processing entity might be less than a week old, but many in the industry would have, no doubt, had some burning questions to ask since the planned merger was announced on July 4, 2019.

IM had a chance to put some of these questions to Stephan Kirsch, President Minerals business area, Metso Outotec, gaining an initial impression of what the combination of the two companies means for the Minerals business he heads up.

IM: What big mining industry challenge will the combined group be better placed to tackle? What equipment/solutions/expertise within the group are the most important in achieving these goals?

SK: One issue – although not technology-focused – is community engagement.

Some mining operations in the world face challenges in terms of engaging with local communities and returning benefits to them. There is a social responsibility for mining companies, as they are the operators, but also for mining industry supporters involved in such projects.

That said, the vast majority of the mining industry runs initiatives that ensure communities understand mining companies are not just there to extract the iron, copper or gold and make money from it. They give back to local stakeholders and help improve community standards.

Stephan Kirsch, President Minerals business area, Metso Outotec

From a technology perspective, an industry issue we are well equipped to tackle is tailings management. With our combined offering, we look very seriously into solutions that can involve dewatering, dry stacking, and the reprocessing of tailings.

You asked about the products involved in solving these challenges…that includes filtration technologies, bulk materials handling products for conveying and stacking, and then various ore sorting technologies for the reprocessing.

Another trend to highlight is the use of energy or, more specifically, the need to reduce power consumption. There is some work to do here.

When you go and buy a car, you tend to focus on the fuel consumption. The mining industry, however, aims for high installed power because there is a sentiment that more power in the mill means more product out of the mill, more fines and, as a result, better downstream recoveries. In a way that is true for technologies like horizontal mills, ball mills and SAG mills, but when you turn to different, newer technologies it is not always the case.

One of these technologies is HPGRs which were introduced in the minerals industry in the mid-80s. Today, HPGRs are used in high tonnage, competent, abrasive ore applications due to their lower specific power draw and other downstream benefits compared to conventional technologies.

One can add to this, conserving other natural resources such as water. Water scarcity is obviously a problem and we should look at the recycling of process water wherever possible (that is where the filtration technology comes into play again) at the same time as examining more energy-efficient flowsheets.

There is quite a bit we can do to solve some of these challenges from a mineral processing perspective, but, the problem is, the industry remains conservative and anything new takes time to be implemented sustainably.

IM: I know Metso has previously talked about creating a bulk ore sorting solution for industry. Considering this, do you as Metso Outotec expect to continue leveraging the agreement Outotec has in place with TOMRA to carry out more sensor-based ore sorting projects? Alongside this, will you continue with your own bulk sorting projects?

SK: Early removal of tailings/overburden from the processing plant feed has been the operator’s dream for probably a century! This concept of preconcentration has been a consideration for many years, but in the last 30 or so years, technologies with different sensors have been developed to help with this separation process.

It is the ability to use sensor technology to single out particles on a conveyor belt at an appropriate speed and quantity that is the industry challenge. After all, when it comes to mining, we are talking about bulk materials that must be processed, not single elements like you have in the recycling and food sectors where much of this sensor technology originated from.

You need to look at the operating economics of such plants. When I say economics, I am factoring in throughput and recovery rates: you want a high tonnage and you don’t want to waste your ore, which is already low grade compared with what was being mined, say, 30 years ago.

The answer to your question is that Metso has been looking into preconcentration technologies for some time – we have R&D projects and partners looking at it. The same is the case with Outotec. Going forward, we will analyse this and make a call on whatever is the best combination to continue with such work.

Personally, I am a big believer in segregating waste as early in the process as possible to save energy downstream. But there are technical challenges to this.

IM: Both companies have been expanding their modular offering in recent years (Metso with its flexible FIT™ stations and the smart Foresight™ stations/Outotec with its modular paste backfill plants and HIGmill): is a lot of your mining and metals R&D currently focused on reducing the footprint of your solutions?

SK: Our R&D budget – as you probably heard on the webcast last week – is quite significant when put together. As Metso Outotec committed to keep both of our budgets unchanged, the spend comes to about €100 million ($112 million). A market survey we carried out revealed that, in terms of R&D spend, we are at the top of the industry.

Then, we must spend this money wisely wherever we see it being applied most economically for the benefit of our customers and for Metso Outotec. The modular crushing stations you mention are an area of interest we started developing years ago. We see good potential for this modular offering and will continue to develop it.

As for the percentage of the budget we will dedicate to it, this will – like all R&D projects – be analysed alongside others for crushing, grinding and all separation technologies with a strong focus on product innovations, digitalisation and sustainability.

IM: As you hinted at earlier, do you see tailings management being one of the combined group’s core strengths?

SK: It is one big focus area for us, but only one.

Crushing and grinding, which I mentioned earlier, is another strong area. We are a market leader in some of the crushing technologies we offer, and high up the industry when it comes to grinding technologies. We plan to really expand on this side.

I mentioned HPGRs where we have brilliant, world-class technology, but are missing the installed base. With 20-25 years of HPGR experience, I know we have the technology to make a difference, we just need to effectively bring it to market.

The whole re-grind space is really a future area for us to pursue due to industry-wide issues of falling grades, the need to reduce power consumption and fine grinding requirements.

Back to the original question, I expect Metso Outotec to be a strong player for dewatering and tailings management solutions.

IM: Outotec has a much more developed downstream business in areas like hydrometallurgy and smelting, etc in mining than Metso – will this remain a core part of the combined group?

SK: The front-end strength of Metso for mineral processing plants and the wet processing business focus of Outotec shows how well both companies complement one another. From a technical perspective, this is one of the reasons why the merger of Metso and Outotec makes much sense.

IM: In what segments of the mining and metals market do you see the most complementary solutions within Metso and Outotec?

SK: When we brought these two companies together it is amazing how many renowned international mineral processing experts came with it. We can provide much more comprehensive services to the industry because we can look at the entire flowsheet – from run of mine ore, to metal.

Why is this so important for our customers? You can bundle equipment together to make tenders and dealing with OEMs more economical for mining companies. But, more than that, we can bring a much larger pool of experts to a project to interact and talk with each other to provide the right innovations. This is the ‘one plus one equals three’ effect.

We can also look at balancing the equipment so, for example, the primary crusher is appropriately configured to produce the right ore for the secondary crushing process and the screens are amply sized to effectively carry out their job. That then leads to finding the optimal operating point for the HPGRs and milling equipment and then the downstream processing segment. This type of equipment balancing is highly interesting for the market, creating win-win situations for customers and us as an OEM.

IM: Do you see your relationship with mining customers changing because of this holistic approach?

SK: Yes and no. There are companies that will appreciate this wider offering and there are others that will continue to come to us as part of a more traditional way of tendering for mineral processing equipment.

I see a trend where larger companies are coming back to reliable OEMs because the availability, sustainability and reliability of equipment is much more important than saving a dollar in capex in the first place. That is a trend we have seen strengthen even more recently with COVID; we all know when a plant is not running, it costs operators hundreds of thousands of dollars per day in lost revenue.

Yet, there are always customers that say capex is king. They will do everything they can to tender it most competitively from a capital expense perspective, regardless of the long-term total cost of ownership benefits choosing another solution will have.

IM: How will your digital offering be strengthened through the combination?

SK: At Metso, we started, especially in South America, with a strong operation and presence in terms of remote control and remote operating and maintenance support for processing plants.

The service solutions that have been developed and established in some countries, specifically for Metso and for Metso equipment, in the new company will, of course, be transferred into the installed base of Outotec (for example, a facility previous owned by Outotec in Espoo, Finland, is now a Metso Outotec Performance Center facility).

We often heard from customers: ‘We have great equipment from the Outotec side, but we have never experienced the great Metso services.’

What is so encouraging to see is that there is demand from the industry for such a combination of equipment and services.

IM: Where do you see an overlap of solutions (for instance, possibly crushing and grinding equipment (SAG/AG/ball mills), vertical crushing tech (Vertimill/HIG mill)) or flotation (Outotec has a greater market share but Metso supplies some interesting options like column flotation, plus is the leader in flotation camera monitoring with VisioFroth)? Historically, have you been competing against each other for contracts in these market segments?

SK: As you know, for 12 months or so, there was intense scrutiny from the regulatory authorities to find out if the companies could merge or not because of an overlap, and the answer that came back is yes.

From a regulatory authority perspective, there is no overlap, and, from a technical perspective, I view it in a similar way.

One prime example to give would be the Vertimill (below, left) and the HIGmill (below, right). If you look at both in detail and you talk to customers – which has happened when we have our project meetings and negotiations – you often find that the applications being examined are so specific that both mills, although close when it comes to operating process, have their own sweet spots.

                      

Most of the cases where we, as Metso and Outotec, won or lost a tender, the argument was not around price or sentiment; it was always technical where, for example, the feed was too coarse for the HIGmill, or the end product needed to be so fine that the Vertimill was ruled out.

We, therefore, want to continue offering both technologies; we will not shelve one because we believe there is room for both solutions.

IM: Could this combination then enable you to offer a more customised solution for customers?

SK: That is where the benefit (from the combined Metso Outotec) for the industry really kicks in; our customers are not just getting standard solutions; some tailoring is involved. They will be able to get more specific and solution-oriented, performance-balanced pieces of equipment.

IM: Would you like to add anything else?

SK: I need to say that I am quite excited about the opportunities for the new company, Metso Outotec. There are benefits for both us and the wider industry.

Personally, I am humbled to be elected to run such a large organisation of industry experts and high-quality equipment. It is exciting times ahead.

Novo Resources to take Steinert ore sorter into the field

Novo Resources says it is in advanced discussions with Steinert Australia to procure a 1 m wide KSS 100F LIXT fine mechanical sorting unit, to be deployed at its wholly-owned Purdy’s Reward and Comet Well JV gold projects, in Western Australia, during the 2020 field season.

The sorter will be manufactured by Steinert in Germany with an expected 18-week delivery time to Australia, Novo said.

Approvals are being prepared for field testing of up to 10,000 t of material from Purdy’s Reward, Comet Well, and 47K, respectively (total up to 30,000 t). Novo also plans to utilize this sorter to test field exploration samples delivered from its other projects including Egina, it said.

Field test work will be designed to better understand gold grades, the extent and location of mineralised conglomerate units, evaluate mechanical sorter gold recovery at production throughput rates and of various sorted size fractions, and provide critical input concerning operational costs, the company explained.

The company has previously carried out ore sorting test work in the lab on samples from its Reward and Comet Well JV gold projects.

Rob Humphryson, Novo’s CEO and a Director, said: “We have achieved outstanding laboratory level mechanical sorting test results utilising both Steinert and TOMRA sorters. It is now time to field test productivity and performance. This Steinert unit will be equipped with technology that is capable of testing material from all our coarse gold projects.”

Humphryson said the decision to initially deploy a Steinert unit into the field was more a reflection of “local, non-technical factors” than any distinct differentiation of capabilities between the two suppliers’ sorters.

He added: “Should field testing of mechanical sorting prove successful, it is likely that the final utilisation of this technology will involve a hybrid solution involving equipment from both suppliers. In light of this, we intend to maintain a close working relationship with both suppliers.”