Tag Archives: grinding

Futureproofing the world’s copper supply through technology use

Realising the vision of a world of clean energy brings the issue of metal supply into sharp focus, with major and sustained increases required to meet growing demands, Thermo Fisher Scientific’s Ellen Thomson* writes.

With copper, for example, there are predictions of a shortfall of 15 Mt per annum by 2034 based on the current output. Therefore, boosting the efficiency of mining operations has never been more important, and smarter technology is undoubtedly the way forward to achieve this. Real-time sampling and measurement right across the mineral processing value chain can arm miners with analytical data, enabling them to build a robust understanding of the performance of each plant and drive continuous improvement at every step of the process. This article takes a closer look at how several of these steps could be optimised, including ore grade measurement, sorting on the mill feed conveyor, particle size analysis in the grinding circuit, the addition of reagents in the flotation circuit and elemental analysis and impurity detection in the concentrate leaving the plant.

Copper miners face the challenge of satisfying the rising demand for metal, while hitting the industry’s 2050 net zero carbon target. This is likely to require significant changes in operations through processing low-grade ore more efficiently, fully exploiting existing deposits, and bringing new mines into production. Unfortunately, higher-grade ore – with a 2-3% metal concentration – has largely been depleted, and miners now often work with concentrations of just 0.5%, meaning greater quantities of ore must be processed to extract sufficient amounts of copper. Therefore, it is essential to seek fresh opportunities to improve processes across the entire mining value chain, so that the increasing demand for copper ore will be met well into the future.

Does your ore make the grade?

Enhancing mining efficiency begins as soon as raw material is extracted from the ground, and extends through the crushing process and the mill feed conveyor. It is important to accurately measure the grade of the plant feed as this will impact both the performance of the concentrator and the production costs of the final product. However, this can be challenging, as some deposits are highly heterogeneous and unpredictable. Bulk ore sensing and sorting are, therefore, crucial steps in improving the raw feed material consistency and concentrator efficiency, since they reduce the dilution of incoming feeds and redirect low or marginal grade material away from the concentrator at the first opportunity. These stages rely on highly accurate and precise analytical technologies to rapidly differentiate material grade and minimise the loss of valuable material, moving only economically viable ore further along in the process. A high spec analyser is vital to this part of the chain and enables small and lower-grade satellite deposits to be accessed more successfully, as well as increasing profits for established plants.

Cracking down on the grinding circuit

Grinding is an essential first step in mineral liberation, but there is often no clear understanding of what the target particle size should be for a given head grade. Producing finer particles liberates more metal, but also increases media and energy costs. More than 50% of the energy consumed at a mine goes into crushing and grinding, so over grinding has definite economic and environmental implications. It is crucial, therefore, for each mine to find a balance between particle size and circuit throughput that limits consumption of grinding media and energy, while still maximising metal yields.

Grinding just enough is critical – too fine means lower throughput and/or higher energy consumption; too coarse and recovery suffers

Once a target has been established, real-time analysis of particle size and head grade elemental composition – for example, by prompt gamma neutron activation analysis (PGNAA) using a cross-belt system such as the Thermo Scientific™ CB Omni™ Agile Online Elemental Analyzer – can have a significant impact on the efficiency of the grinding circuit. In addition, by standardising particle size and controlling composition through the plant feed and grinding stages, the stability in feed forward control is increased going into the next stage – the flotation circuit.

The CB Omni™ Agile Online Elemental Analyzer (Thermo Scientific) rapidly and accurately differentiates material that is at or below the cut-off grade for ore sorting, the company says

Fine-tuning flotation

Flotation is a complicated physicochemical process where reagents – such as frothers, collectors and pH modifiers – are introduced to promote separation. The flotation feed can vary in particle size and chemistry depending on how the grinding circuit is optimised, and may contain excess fines. Miners might choose to compensate by adding more reagents, which can sometimes be beneficial but can also incur greater financial and environmental costs. Therefore, it is important to tailor the dosages of the flotation reagents in response to the incoming ore grade and particle size.

Concentrating on monitoring impurities

Certain impurities compromise the value of a concentrate, but they are often overlooked. Detecting impurities in the concentrate ahead of shipping reduces the chance of rejection at the receiving site – and the subsequent financial losses – and has the potential to improve ore quality, strengthen a company’s reputation and reduce the risk of penalty charges. In fact, representative sampling throughout ore extraction to concentrate the production process should be considered, but this can be extremely challenging owing to concentrated slurries, high tonnages, long distances between sample and analysis, and the expense and complexity of tackling head constraints.

Multi-stream analysers – like the Thermo Scientific MSA 3300 Slurry XRF Analyzer – are commonly employed in the mining industry, and can seem like an excellent, cost-effective solution. However, multiple streams can reduce efficiencies and lengthen the time to results – leading to less responsive control – and so their low upfront cost should be carefully balanced with their long-term implications. Choosing high quality analytical equipment that requires minimal manual input and has a proven record of reliability could help overcome these challenges and offer a better long-term solution. For example, a dedicated online sampling and elemental analysis station, such as the AnStat-330, provides a versatile and compact solution for addressing issues related to the process control of critical streams, time to results, the distance from sampler to analyser and the requirement for a metallurgical accounting quality sample.

 

 

The MSA 3300 Slurry XRF Analyzer (Thermo Scientific) measures up to 12 streams, with full stream separation retained throughout, Thermo Fisher says
The Anstat-330 Slurry Online Sampling and Elemental Analysis Station (Thermo Scientific) comes with options for additional process functionality, including distribution and pebble screening

Future-ready mining technology

It is vital to detect and understand why mining processes may be operating sub-optimally to know how to improve them. Relevant, reliable digital information is the foundation of an efficient operation and investing in more effective and continuous analysis is a key strategy for increasing return on investment. Digital twins, for example, integrate and collect data from sensors into a cloud platform to construct a complete and fully representative digital version of the concentrator. This allows miners to model different scenarios – such as changing process parameters – without interrupting the real-world activities of the mine. They aid in decision making and help to prevent unnecessary expenditure, as well as identifying any operational bottlenecks. Mining companies could potentially achieve 20 times – with some estimates up to 40 times – return on their initial investment through implementing digital twins, and more easily establish advanced, automated process control, increasing efficiency and depopulating mines.

Digital innovations are undoubtedly going to transform the mining industry and will help to reduce resource consumption and meet future sustainability goals. Without reliable, timely feedback, process control will always be on a ‘trial and error’ basis, which is no longer sufficient if miners are to fulfil the increasing copper demand ahead of us. Thermo Fisher Scientific supports the mining industry in adopting such technologies to enable dependable, timely and, often, real-time measurements that provide the data that miners need to track metal values, all the way from exiting the mine through to concentrate shipping.

*Ellen Thomson is PGNAA & Minerals Senior Applications Specialist at Thermo Fisher Scientific

ABB adds cloud functionality, app use to Ability Predictive Maintenance for grinding

ABB has released a new version of ABB Ability™ Predictive Maintenance for grinding which allows users to obtain real-time notifications on gearless mill drive (GMD) systems from a mobile app.

The upgrade also means that ABB Ability Predictive Maintenance for grinding is now cloud-based instead of sited on premises.

The Grinding Connect mobile app, available for iOS and Android, allows mine operators to monitor performance at any time and from any place.

“ABB Ability Predictive Maintenance for grinding provides easy access to GMD system parameters and allows visualisation of performance considering past activity and real-time data and assesses future maintenance requirements,” ABB said. “It aims to extend the lifetime of grinding assets through better use of resources and to support non-stop operation and to avoid unforeseen downtime.”

The update facilitates greater data gathering, according to the company, with the data sample per mine increased and analytics and trends more reliably defined. The solution offers a new user experience with fully customisable dashboards, alarms and events all available on the mobile app.

ABB says GMDs are the preferred grinding solution at mines characterised by higher-capacity production and low-grade ores. By eliminating bolt-on mechanical components such as ring-gears, pinions, couplings and gearboxes, GMDs offer ore producers unrivalled availability, efficiency and durability, while reducing operating costs, according to the company.

Angeles Fernandez, Global Product Manager for Grinding Service in mining at ABB, said: “A gearless mill drive is a major investment and its availability is essential for the process. Unscheduled shutdowns and system failures can lead to significant losses in production.

“ABB Ability Predictive Maintenance for grinding is a state-of-the-art service for analysing system data, assessing the current condition of the equipment and applying predictive methods. The new version is unique in the market and the new Grinding Connect app means you can check that your GMD is performing through your phone or tablet – it is as familiar as the many personal apps we use for monitoring our health, catching up with the news, or checking on the home or children.”

The world’s first gearless mill drive was delivered by ABB in 1969 and is still in operation. Since then, the company has sold more than 150 units in 23 countries and currently has over 50% market share.

Metso Outotec refines grinding mill selection options with Horizontal Mill Plant Units

Metso Outotec is launching what it says is yet another unique solution in its range of minerals processing plant islands: the Horizontal Mill Plant Units.

The pre-engineered plant units provide optimised grinding performance and simplify project management through easy circuit selection and flowsheet implementation, according to the company. At the same time, they ensure safe operability and maintainability thanks to state-of-the-art design.

The plant units feature Metso Outotec’s technologies including grinding mills, slurry pumps, hydrocyclones, conveying equipment, automation and service support. The scope of the unit can be tailored according to project requirements (brownfield or greenfield, open or closed circuit), the company said.

Fernando Marques, Global Product Manager at Metso Outotec, said: “Choosing the right solution for a grinding process can be a complex task. In addition to financial and technological aspects, miners must also evaluate executional and operational factors. Our modular Horizontal Mill Plant Units have been developed to make it easier for customers to select and execute the best solution for their grinding needs. Our pre-engineered modules provide a safe and optimised solution for many grinding applications.”

The units combine Metso Outotec horizontal mills, classification, pumping and automation technologies with a wide range of services and operation support. It takes sustainability and grinding performance to a new level by optimising the usage of energy, water, grinding media and consumables, Metso Outotec said. Other benefits include access to grinding and classification expertise to support flowsheet implementation; pre-engineered modules for simple and rapid execution; a process performance guarantee; easy process optimisation thanks to automation and digitalisation features; and sustainable technology with safe operability and maintainability.

Metso Outotec to deliver bauxite grinding package to NALCO alumina refinery

Metso Outotec has been awarded a contract for the engineering and delivery of a bauxite grinding package to National Aluminium Company’s (NALCO) Damanjodi Alumina Refinery as part of NALCO’s fifth stream expansion project in Odisha, India.

Typically, the value of this type of an order is in the range of €12-15 million ($14.2-17.8 million). The order has been booked in the company’s Minerals June quarter orders received.

Metso Outotec’s delivery includes basic design of bauxite silos and engineering and supply of two ball mills with a capacity of 434 t/heach, apron feeders, agitators, slurry pumps, instrumentation, as well as site advisory services.

Kamal Pahuja, President, Middle East and India at Metso Outotec, said: “We are extremely happy to continue our co-operation with NALCO. This is the third order we have received for their current expansion project in Odisha. The other two orders include two energy-efficient flash evaporation plants and two alumina calciners along with a hydrate filtration plant.”

Metso Outotec ball mills, Vertimills heading to Mapa’s Liberia and Burkina Faso gold mines

The Turkish conglomerate, Mapa Group, has awarded Metso Outotec a contract for the delivery of key grinding technology to its gold mine expansion projects in Liberia and Burkina Faso.

The value of the order is approximately €19 million ($23 million), and it has been booked in the company’s Minerals June quarter orders received.

Mapa is a major conglomerate working in various industrial and construction sectors, including mining.

Mustafa Bülent Karaarslan, COO of the Mapa Group, said: “For us, good support, reliable project execution, and sustainable equipment and process performance are essential. Alongside the existing good relationship between the companies, they’re the reasons why we selected Metso Outotec for these projects.”

Metso Outotec will deliver identical grinding lines to both sites, consisting of state-of-the-art Premier™ ball mills (one pictured) and energy-efficient Vertimill® VTM-3000 stirred mills, each line featuring a capacity of 400 t/h. The deliveries are expected to take place in January 2022.

Mert Katkay, Head of Minerals Sales for Metso Outotec in the Middle East and Turkey, said: “We are excited that Mapa has chosen us to deliver the key equipment for the expansion of these two projects in Liberia and Burkina Faso. Previously, we have delivered the key crushing, screening and grinding equipment to these two mines.”

Weir Minerals wins large comminution order from Nigeria iron ore mine

Two of the largest screens built by Weir Minerals Africa are being designed and manufactured in South Africa as part of a process solution for an iron ore mine in Nigeria.

According to Tiisetso Masekwameng, General Manager Comminution at Weir Minerals Africa, the flowsheet accepted by the customer includes equipment for screening, washing, and grinding supplied by Weir Minerals.

“Within our scope of work are the two largest Enduron® double-deck banana screens built by Weir Minerals,” Masekwameng says. “This is made possible by the depth of design expertise in our Separation Technology Group, an eight-strong team conducting research and development.”

Steven Hunter, Separation Technology Group Leader at Weir Minerals Africa, says the two 51 t Enduron double-deck banana (DBHG 43/97) screens (one pictured) for this project were built upon the designs of the existing Weir Minerals screens range. These large machines measure 4.3 m wide and 9.7 m long and can process 1,750 t/h.

“The customer’s production requirements demanded this considerable size, so we optimised the design by minimising mass without compromising structural integrity,” Hunter says. “We conducted extensive finite element analysis on the whole machine but focused on the main structural elements, ensuring that the units were fit-for-purpose while still being light enough to be driven by the exciters.”

The size of the units still demanded the design and manufacture of Weir Minerals Africa’s largest exciter yet – the Enduron LTX 10. With 120 t of excitation force (at maximum setting), these units will drive the screens at a stroke of 9.4 mm and a gravitational force of 4.6 G.

Hunter said the screens are ready to be fitted with Weir’s IIoT platform, Synertrex. “This allows the machines to be monitored remotely; the system can measure the machine’s performance and any deviations arising that may require proactive attention,” he explained.

The order for Nigeria also includes two Trio® jaw crushers, two Trio cone crushers, two large 2 m by 8 m Trio apron feeders, two Trio pan feeders, eight Enduron vibrating screens and an Enduron HPGR.

For the clay washing circuit, Weir Minerals Africa will supply the mine with a Trio twin-shaft blade mill and Trio twin-shaft coarse washers as well as Warman® slurry pumps.

Metso Outotec delivers ‘next evolution’ in high pressure grinding rolls with HRCe

Metso Outotec has launched the “next evolution of the high pressure grinding roll”, with the delivery of its HRC™e HPGR.

The original HRC HPGR was launched back in 2014 by Metso (now Metso Outotec), pioneering the use of flanges and non-skewing design. The grinding performance that brings energy efficiency, lower circulating loads and increased throughput is now strengthened with an additional evolution in design, Metso Outotec says.

The new HRCe comes with a decreased installation capital expenditure compared with the original HRC. Changes in design allow for maximum productivity with proven technology that leads to superior grinding efficiency.

Christoph Hoetzel, Head of Grinding business line at Metso Outotec, said: “We are very excited about the new HRCe, which combines proven technology and customer-focused evolutions. Metso Outotec is the only OEM that has been able to design and develop reliable flanged HPGR technology that has demonstrated superior performance for many years in the mining industry. We will continue utilising our proven technology but have evolved the design to maximise value for our customers and superior grinding efficiency.”

The high throughput comes from the elimination of the edge effect with the flange design, which will ultimately maximise the amount of crushed material, the company says. With the anti-skew assembly, customers will find faster restarts and no downtime from skewing events, according to Metso Outotec.

The HRCe also comes with a large feed size acceptance of 60-120 mm and improved energy efficiency compared with similar HPGRs, the company says. It also boasts typical capacities of 1,810-6,930 t/h.

Key benefits of the new HPGR include:

  • Improved energy efficiency of up to 15%;
  • Lower circulating load of up to 24%;
  • Increased throughput of up to 19%;
  • Elimination of edge effect from combination of proven flange design and anti-skew assembly; and
  • Elimination of downtime caused by skewing events.

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.

Outotec adds HIGmill to list of modular mining solutions

Outotec is modularising its high intensity grinding mill solution as it looks to improve safety, speed up return on investment and minimise plant footprints when it comes to grinding mill installations.

The Outotec HIGmill plant (HMP) is a standalone, modular solution for fine grinding that addresses these conflicting requirements, the company says.

Consisting of a vertical HIGmill unit and pre-engineered auxiliary equipment modules to reduce engineering, delivery, construction, and commissioning time and cost, it still provides a safe solution with the flexibility to meet various process, layout, and regulatory requirements, according to the company.

These modules are preassembled in the factory to reduce safety risks and maintain the highest possible quality while also reducing on-site construction time and cost.

“The modules and vertical HIGmill can be arranged in a compact footprint to suit the specific site layout, minimising layout and engineering work,” Outotec said.

The HMP includes an Outotec PSI® 500i particle size analyser for continuous online process monitoring and feedback, while the HIGmill provides process flexibility by adjusting the speed to match the energy input for the required product particle size. This, the company says, minimises the risk of operational challenges and reduced recoveries resulting from variable process conditions.

Bjorn Nielsen, Director – Product Management, Grinding at Outotec, talking about the benefits of using the HIGmill®, told IM earlier this year: “The Outotec HIGmill has several key advantages over other fine and ultra-fine grinding technologies. The vertical arrangement means that gravity helps to compress the media bed, ensuring high contact loads between media symmetrical energy transfer throughout the charge. As a result, the HIGmill has a very broad operating range – energy efficiency is very similar for a range of media charge levels and operating speeds.

“This operating flexibility lets us deal with variations in feed particle size while maintaining efficient operation – there is no point having the most efficient equipment in the world if it cannot be continuously operated at its most efficient.”

Riddhika Jain, Product Manager at Outotec, said the HMP combines Outotec’s leading fine grinding technology with faster installation and a compact footprint while maintaining safety standards.

“This standalone modular solution comes in easily installable pre-assembled sections to speed up returns on investment,” Jain added.

Like Outotec’s other modular solutions – such as the VSF®X modular concept and Modular Paste Backfill Plant – the HMP helps optimise delivery lead time and site construction planning. The delivery scope typically consists of a HIGmill, cyclone, hoppers, pumps, media crane, steel modules, switch room, pipes, valves, instruments, and control system.

NRRI and Weir Minerals offer up HPGR alternative to Minnesota Iron Range operators

The University of Minnesota Duluth’s Natural Resources Research Institute (NRRI) is helping introduce high pressure grinding roll (HPGR) technology to Minnesota’s Iron Range.

Working with Weir Minerals, NRRI acquired an industrial-scale Enduron® HPGR to carry out testing on a variety of ores with this process. This is the only large scale HPGR dedicated to research in the US, NRRI claims.

The NRRI explained: “Traditional taconite pellet-making processes use a rod mill to get the rock to the consistency of coarse sand, and a ball mill to grind the rock into a fine powder. This technology is still in use on Minnesota’s Iron Range by some facilities.

“A taconite plant may have as many as 18 rod mills with one rod alone weighing as much as 500 Ib (227 kg). Tumbling around in the mills with the hard taconite wears away the rods and balls and need to be replaced frequently.”

This is a costly and energy-intensive process and the waste rods and balls are a disposal problem, according to NRRI.

NRRI researchers think there’s a better and more efficient way of carrying out this grinding process with the use of HPGRs.

Tim Lundquist, Weir HPGR Manager for North America, said: “NRRI has done a lot of testing for many of our projects. The proximity to the Iron Range is key, but we’ll also bring in material from all over the US, Canada, and elsewhere when it makes sense. Our preference is to work with NRRI whenever possible due to their flexibility, expediency and expertise.”

Unlike rod or ball mills, HPGRs reduce particles by compressing and crushing the feed between two counter rotating, parallel rollers with a small gap between them. This forces the rocks against each other. There are no rods or balls that need replacing and it reduces energy consumption by about 40% for certain ore types, Breneman said. It also substantially reduces water consumption compared with rod and ball mills.

Reducing energy, eliminating costly grinding media, and higher machine availability will make the Minnesota iron industry more cost competitive while also offering the opportunity to reduce greenhouse gas generation, NRRI said.

NRRI Metallurgical Engineer, Shashi Rao, Lead Researcher on HPGR-related projects at NRRI Coleraine, said: “It’s really helpful to the industry to have their ores tested in our large HPGR before replacing their rod or ball mills.

“We’re able to determine if the ore is amenable to high pressure roll crushing, identify the mineral composition, and test a variety of pressures and roll speeds. Third-party testing is very important.”

Keeping the project moving ahead during the COVID-19 pandemic required extra steps and protocols, according to NRRI. This work was coordinated by NRRI Project Engineer, Jeff Kinkel.

“The machine is isolated to one specific area,” Kinkel said. “We adhered to strict sanitation and masking requirements and communicated daily with the contractor doing the installation.”

NRRI acquired the HPGR technology via Weir Minerals from the shuttered Magnetation LLC operation and both organisations are sharing the cost of maintenance.

“This is a great example of a partnership project,” Kevin Kangas, NRRI Coleraine Director, said. “We’ve been working on this for over two years and it’s exciting to have the global interest in this capability.”

The process is now in place at a Minnesota Iron Range facility with a Weir Minerals Enduron HPGR.

On average, 53% of a mine site’s energy consumption is attributed to crushing and grinding ores, accounting for almost 10% of a site’s production costs, according to information from Weir Minerals. NRRI’s HPGR is manufactured in the Netherlands by Weir Minerals.