Tag Archives: Crushing

CSI to deploy ‘innovative’ screening solution at Roy Hill iron ore operations

CSI Mining Services (CSI), a wholly owned subsidiary of Mineral Resources Limited (MRL), has been awarded a mining services contract by Roy Hill at its iron ore operation in Western Australia’s Pilbara region.

This new contract builds on CSI’s long-standing relationship with Roy Hill, which has seen CSI provide crushing and screening works since early project inception. The new contract will see CSI deliver an expanded scope of work which includes crushing, screening and haulage services.

CSI says it is uniquely positioned as a key service provider to Roy Hill given its strong track record of exceeding performance targets and detailed understanding of the mine and its operational processes and procedures.

In delivering the new contract CSI will deploy an innovative new screening solution to deliver industry-leading efficiencies to the project. The screening solution is an exclusive product to CSI and is not available on the market, giving CSI a distinct design advantage.

Mineral Resources’ Chief Executive Mining Services, Mike Grey, said: “We are very pleased to be selected as preferred mining contractor by Roy Hill to provide safe and efficient crushing, screening and haulage services, following the successful completion of our previous contract.

“Our track record at the operation demonstrates that we can mobilise quickly and exceed production targets, while maintaining an industry leading safety record.

“Our mining services business has delivered strong growth year-on-year and this new contract for Roy Hill reinforces CSI’s position as a market leading mining services contractor.”

Roy Hill Chief Operating Officer, Anthony Kirke, said: “CSI has been a valued partner to Roy Hill since February 2017, initially providing crushing services, followed by the addition of screening and associated haulage services for our Direct Shipped Ore. CSI’s agility in responding to changing operational requirements, commitment to innovation and continuous improvement and alignment with our values have resulted in positive outcomes for Roy Hill.

“The award of this new and expanded multi-year contract reflects the strong relationship between our two companies and we look forward to the deployment of CSI’s new screening solution at our mine site.”

Metso Outotec expands India facility on track-mounted crushing/screening equipment demand

Metso Outotec is to invest in extending its current manufacturing capacity of mobile track-mounted crushing and screening equipment in Alwar, India.

The total Alwar production value is planned to grow by 30% from the current level and global track-mounted mobile machine capacity by 15%, the OEM said. Construction of the new factory facilities is planned to start in early 2022, and be completed by the end of the year.

The increased capacity in India will be used for the manufacturing of McCloskey mobile and Lokotrack equipment, employing approximately 200 additional people. After the extension is completed, the Alwar factory will be one of the biggest manufacturing sites of Metso Outotec, employing some 800 people, the company said.

“This is another step in developing our domestic and export business in India,” Markku Simula, President of the Aggregates business area of Metso Outotec, said. “At the same time, we are also investing significantly in engineering and R&D resources in Alwar and making it one of our global engineering hubs.”

FLSmidth set to showcase lithium engineering expertise at ioneer’s Rhyolite Ridge

ioneer Ltd has awarded a major engineering and equipment supply contract to FLSmidth for the development of the Rhyolite Ridge lithium-boron project in Nevada, USA.

The contract has been awarded on a limited notice to proceed (LNTP) basis, with the supply of the equipment packages being conditional on a final investment decision on the project by ioneer’s Board of Directors.

Under the contract, FLSmidth has commenced work on product engineering for the equipment packages, which include crushing and material handling equipment, plus lithium carbonate and boric acid dryers.

FLSmidth, Ioneer says, has significant experience in providing technology, equipment, engineering and services expertise to the battery minerals sector. It has a strong US presence and is committed to improving project efficiency while reducing environmental impacts on site.

FLSmidth has also introduced ioneer to Denmark’s Export Credit Agency (EKF) regarding potential financing options.

ioneer Managing Director, Bernard Rowe, said: “The contract with FLSmidth is one of the more significant supply packages we will award at Rhyolite Ridge and represents another step in the development of the project.

“FLSmidth is focused on providing environmentally sound engineering and technology solutions. This aligns with ioneer’s ambition to not only produce materials necessary for electric vehicles and renewable energy infrastructure, but to do so in an efficient and environmentally responsible manner through lowered emissions, significantly reduced water usage and a small surface footprint.”

FLSmidth Mining President, Mikko Keto, said: “This contract provides clear recognition of our experience, know-how, and world-class technologies for processing lithium. It is also important to note that our localised approach and strength in service and aftermarket were important factors for ioneer when it came to choosing a partner.”

The lithium and boron resource at Rhyolite Ridge is estimated at 146.5 Mt, including a reserve of 60 Mt. The company expects to mine and process 63.8 Mt over the 26-year mine life at an average annual rate of 2.5 Mt/y. This will see it produce, on average, 22,340 t of lithium carbonate (99% purity) (years 1 to 3), 21,951 t of lithium hydroxide (99.5% purity) (year four onward) and 174,378 t boric acid (life of quarry).

Metso Outotec, Mineral Resources deliver the next generation of crushing

What will crushing plants of the future look like? Mineral Resources Ltd and Metso Outotec have pondered that question and have since gone on to answer it with the delivery of a modular, scalable and relocatable plant at an iron ore operation owned by one of the world’s biggest miners.

Called ‘NextGen II’, the solution represents a ground-breaking approach to delivering safe and reliable production to the hard-rock crushing industry, Mike Grey, Chief Executive of Mining Services for Mineral Resources, says.

And it all started with a test for one of the company’s most technically minded individuals.

“We were sitting around the boardroom table with David De Haas, one of our key engineers on this project, and gave him the challenge to come up with a crushing plant that we could literally relocate anywhere very quickly, build on a very small footprint, and have it plug and play,” Grey told IM in a recent IM Insight Interview.

Mineral Resources, which counts CSI Mining Services (CSI) as a wholly-owned subsidiary, was in a unique position to deliver on this.

A provider of world-class tailored crushing, screening and processing solutions for some of the world’s largest mining companies, CSI specialises in build, own, operate (BOO) projects where it provides both the capital infrastructure and the operational expertise to ensure these crushing plants operate to their potential on site.

It carries out crushing services for Mineral Resources’ own mines, as well others across the mining sector.

Crushing collaboration

When offering such ‘crushing as a service’ type of contracts, the service must be underpinned by the best equipment possible.

Enter Metso Outotec.

Having initially commenced discussions with the global OEM in early 2019 (when it was still Metso), Mineral Resources, later that year, agreed with Metso on the design and delivery of a new type of crushing solution.

The pair recognised early on in these conversations that the industry was changing and they, as service and solution providers, needed to change with it.

The largest bulk commodity operations in the world are made up of multiple pits that get mined over time. As these operations expand, miners are left with a dilemma: extend the haulage time from the pit to the plant or build another plant.

The NextGen II crushing plant has provided a third option.

(Credit: Mineral Resources Ltd)

De Haas, collaborating with Metso Outotec, has delivered on the board’s brief with the design for a crushing plant able to produce 15 Mt/y using a modular design made up of several stations. The plant can move with the mining, being erected and taken down quickly without the type of in-ground services that can scupper such moves.

The first plant delivered under this collaboration is now operating in the Pilbara at a very well-known iron ore operation.

Customised crushing

Guillaume Lambert, Vice President of Crushing for Metso Outotec, provided some specifics.

“The NextGen II is a crushing and screening plant to crush iron ore and produce lump and fine products,” he said in the IM Insight Interview. “The process starts with a primary station made up of a Metso Outotec apron feeder (below left), followed by a vibrating grizzly scalper.” Then starts the size reduction process with a Nordberg C150 jaw crusher (below middle).

From this primary station, the ore goes to three secondary crushing stations, each comprised of an MF3072 banana screen (below right) and Nordberg HP400 cone crusher.

(Credit: Metso Outotec)

Fines and lump are the products from this secondary station, with the oversize arranged in close circuit with the screen, Lambert said.

The screen was designed specifically for the project – offering the compact dimensions that could fit inside the station’s footprint. Other customised add-ons included specialised cooling rooms for the lubrication units and extensive steel fabrication works.

Lambert added: “Really, the tailoring of design is around the modularity of the different stations. Each station is made up of several modules. All those modules can be pre-assembled and tested in a factory and transported by road to the site. This has been established to enable a fast erection process.”

This turned out to be the case with the very first NextGen II installation.

Despite a timeline setback caused by the global pandemic, the 1,500 t of steel needed for the plant construction was built in 16 weeks, starting in March 2020 and ready by July 25 of that year. It was shipped to CSI’s Kwinana facility in Western Australia for pre-assembly before delivery to site.

Final commissioning took place in early 2021, and the crusher has been working well since.

(Credit: Mineral Resources Ltd)

R U OK?

A distinctive blue colour, the plant reflects Mineral Resources’ commitment to mental health awareness and support, carrying the phone number and colour of Lifeline, a Western Australia-based charity formed to prevent suicide, support people in crisis and reduce the stigmas which can be a barrier to seeking help.

“It is really important for us to promote mental health; our fly-in fly-out workforce has matured over some years, but the challenges around working remotely remain,” Grey said. “It is important that we demonstrate we have the support mechanisms in place to support our workers and their families.

“The NextGen II plant is at the forefront of that – it is the first thing people see when they come to work and the last thing they see when going home. They can always reflect and make sure their work mates are OK.”

(Credit: Mineral Resources Ltd)

Support and service

The plant’s operating success has been helped by a local service and support network from both companies, with Metso Outotec providing critical spares and all large “rotable refurbishments” serviced by CSI’s Kwinana facility.

This is underwritten by a remote condition monitoring service that can see personnel and parts from both companies deployed to site at a moment’s notice.

This comprehensive offering has seen close collaboration between Metso Outotec’s Minerals (capital equipment) business, Service business and MRL’s own service team.

Understanding the challenges and potential delays for parts deliveries due to MRL’s remote location, the companies agreed to a specific consignment inventory close to the site to ensure parts availability and exclusivity for MRL to better support the operation.

In addition, a Metso Outotec service expert is present for maintenance and shutdown events to provide expertise and support to the MRL maintenance team.

Grey and Lambert said the collaboration has been a win-win for both companies.

“Working with Metso Outotec on this project has allowed us to define the scope together, rather than remotely,” Grey reflected. “That allows us to ensure we deliver to the timelines and then make any necessary changes on the run, hand-in-hand. We deliver the solution together.”

Lambert added: “Metso Outotec is an indisputable leader in crushing and screening technology, as well as plant. However, working with MRL, we learned a lot about improving the design of our station to maximise safety and improve accessibility in a very, very compact environment for high-capacity plant.”

In demand

This is unlikely to be the first and last next generation crushing plant to come out of the OEM/service provider collaboration.

While iron ore was the commodity of choice for the first installation, Lambert said there was potential for these types of plants featuring in base and precious metal operations.

“The NextGen II plant is very flexible,” he said. “Each station is individually plugged into the solution, and we can easily upgrade the crusher, the screen, etc throughout the year depending on capacity needs.”

Adding or removing some stations could see the throughput reduced or increased, with Lambert even talking about the ability to construct a 30 Mt/y plant that can be built, erected and relocated in the same way as the first 15 Mt/y plant.

“In addition, NextGen II, today, is designed for iron ore applications with lump and fine products,” he said. “If we want, we can add a tertiary crushing stage in order to produce only fines for iron ore. This can match with copper and gold operations also.”

There are plenty of gold miners extracting ore from multiple pits that could provide a strong business case for the installation of such a plant. Similarly, there is potential for this working at major open-pit copper mines.

Lambert concluded: “There is, for sure, global demand for modular crushing plants. Today, having a fast and safe erection process is a must in many countries and locations. In addition, we have more and more short-term operations emerging in very remote locations, so having the possibility to minimise civil works is key for a lot of our customers.”

To watch the full IM Insight Interview on ‘Mining’s next generation of crushing solutions’, click here.

Pilot Crushtec and Metso Outotec extend partnership

After five years representing global leader Metso Outotec in southern Africa, South Africa-based Pilot Crushtec has renewed its distributorship for another half decade.

Pilot Crushtec, despite periods of challenging economic conditions in recent years, has earned global accolades within the Metso Outotec distributor network, with Francois Marais, Director Sales and Marketing at Pilot Crushtec, saying the company has already won annual awards for Best Aftersales Distributor and for Best Sales Growth.

“We value this partnership with one of the world’s leading brands and have demonstrated through our solid performance the positive synergies that we leverage,” Marais says. “The years from 2017 through to 2019, in particular, saw exceptional growth year-on-year for both our Metso Outotec offering and our business as a whole.”

He highlights that the two companies’ offerings in the crushing and screening market complement each other very well, and they share a commitment to high quality products, service and support.

“For customers, the renewal of our distributorship confirms their faith in our products and strengthens their security of investment going forward,” he says. “It assures the market once again that their capital investments are being well supported through our extensive parts holdings and service excellence.”

The new agreement covers additional products and territories within the region, facilitating a wider offering in terms of new equipment and aftermarket aspects. According to Adam Benn, Director Capital Sales, North EMEA, Russia & CIS and Southern Africa at Metso Outotec, there was no hesitation in renewing the distribution agreement with Pilot Crushtec.

“Having just celebrated its 30th anniversary in business, Pilot Crushtec has built a strong reputation,” Benn says. “This applies not only to their supply of equipment and associated services, but their experienced team’s hands-on knowledge and can-do attitude to opportunities and challenges.”

He emphasised Pilot Crushtec’s investment in time and resources training their teams and their customer base – an effective strategy for keeping skills current and for listening to customers’ development needs. With technical facilities that, it says, rank among the industry’s best, the company manufactures plant locally while also offering a one-stop repair and refurbishment solution.

“Having a distribution network that is close to its customers is a fundamental part of Metso Outotec’s group strategy,” he says. “In addition to being well located, our distributors need to keep a good inventory of equipment and parts, which is something that Pilot Crushtec prioritises as a vital cornerstone of their business strategy.”

Metso Outotec boosts end-user service offering in central, southern Sweden

Metso Outotec has signed a distribution contract with Mining and Construction Equipment Sweden AB and Värnamo Krosskonsult AB that will see the two Sweden-based firms distribute Metso Outotec’s mobile and stationary crushing and screening equipment, as well as crusher wear parts, to mining and aggregate customers in southern and central Sweden. The pair will also provide service support such as start-ups and repairs in the regions.

Roar Vasbø, who is heading Metso Outotec’s sales and service in the Nordics region, said: “We’re very pleased to enter this cooperation. For the customers, it means better and faster local service. For us, it means that we can improve customer experience and reach out to more potential customers in the region, especially contractors.”

Fredrik Wennberg, Managing Director of Mining and Construction Equipment Sweden, said: “Our aim is to serve the markets as one-stop-shop. We offer service, parts, equipment and know-how close to the customer.”

He added: “Flexibility is very important to our customers, especially for the contractors. We offer rental possibilities and stock units so that the customers are able to get their equipment quickly.”

Kristofer Almén, Managing Director of Värnamo Krosskonsult, concluded: “This is a great opportunity for us to be able offer Metso Outotec aggregate equipment to greenfield projects or to brownfield stationary plant projects. It will strengthen our competitiveness and help us serve the market better.”

The main location is Värnamo with equipment and parts stock, and a service workshop. Sales offices are in Stockholm, Värnamo and Ystad. The staff includes around 20 personnel in service, sales, and construction engineering.

MLG Oz bolsters NSR Jundee work, adds Norton Gold Fields and Mincor to contract mix

MLG Oz says it continues to experience historically high levels of tendering opportunities for its suite of mining services, with three new integrated site services and haulage contracts recently added to its remit across its Western Australia operations.

MLG, which listed on the ASX earlier this year, says it offers a range of value added services from bulk haulage, crushing and screening, aggregate and sand supplies through to export logistics.

At Northern Star’s Jundee gold operation in Western Australia, the company has been awarded preferred contractor status for an expansion of its services, providing integrated site support and haulage capacity at the mine. Subject to negotiation and execution, this new three-year contract is expected to commence around August and deliver some A$12 million/y ($9.2 million/y) in revenue.

The scope of works will consist of integrated site support to the company’s mill feed operations from both its Jundee central underground mines and its regional satellite operations, MLG said. It will see the ASX-listed contractor conduct all crusher feed, bulk haulage and site civil works for the operations under its integrated operating platform.

MLG has added two new clients to its roster, too – Norton Gold Fields and Mincor Resources.

Norton Gold Fields has chosen MLG as its successful tenderer to provide integrated site support services and haulage for its Paddington gold operation over a three-year period expected to commence in September. Revenue from this opportunity is estimated to be around A$14 million/y, with formal contract documentation anticipated to be finalised in the coming weeks.

And, in line with MLG’s desire to broaden its service offering across different commodities and, in particular, the battery metals space, it has executed a contract with Mincor Resources for the provision of the logistics services associated with its Kambalda nickel operation. The contract is expected to deliver approximately A$3 million/y in revenue over four years and is expected to commence in the March quarter of 2022.

Reviewing these contract awards, MLG Founder, Managing Director and majority shareholder, Murray Leahy, said: “We are very pleased to be given the opportunity to continue to support and grow with Northern Star which has been a long-standing customer of MLG.

“We are delighted that the Norton Gold Fields Board has selected MLG to support the Paddington processing facility. The mill is 35 km northwest of Kalgoorlie and aligns very strongly with our existing Kalgoorlie network.

“Our new contract at the Kambalda operations is an important first step for MLG in developing a longer-term relationship with Mincor in support of its goal of being a key supplier of nickel to the emerging battery metals market.”

In addition to announcing these contract awards, MLG also provided a market update on its crushing and screening activities.

It said: “MLG’s crushing and screening operations, which account for 20% of MLG’s forecast financial year 2021 revenue of A$241.6 million, have experienced a reduction in available material to process from several clients across the last quarter of financial year 2021, due to production constraints at various client operations. We anticipate this will negatively impact the crushing and screening revenue in the first half of financial year 2022. Despite this, and given the company’s current pipeline, including as evidenced above, the board expects the overall impact of this to be mitigated in the second half of financial year 2022.”

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.”

The Axora take on crushing and comminution

As we are continually told, comminution is one of the most energy intensive single steps in the resource extraction business.

One estimate is that it accounts for 36% of all the energy used in the extraction of copper and gold, which is only a shade over the 30% proposed as an average by another industry expert for all mining and mineral processing industries.

It also accounts for an estimated 3% of the global energy requirement for metal production.

These energy requirements are shocking from a sustainability and greenhouse gas emission perspective; they are also extremely costly regarding operating expenses on site.

It is with this in mind that IM touched base with Joe Carr, Industry Innovation Director of Mining at Axora.

A spinoff from the Boston Consulting Group, Axora has emerged as a business-to-business digital solutions marketplace and community for industrial innovators. It says it allows industrial companies to discover, buy and sell digital innovations and share knowledge in its community, powered by an advanced marketplace.

“We exist to transform industries to be digital, safer, more sustainable and efficient,” the company states on its website.

Having recently gone to press with the annual crushing and comminution feature (to be published in the IM April 2021 issue), IM spoke with Carr to find out what the Axora marketplace has to offer on the comminution and crushing front.

IM: What are the main issues/concerns you continuously hear from your mining clients when it comes to designing and maintaining comminution circuits? How many of these problems/issues can already be solved with existing technology/solutions?

JC: One of key issues in this area we hear from our customers at Axora is the blending quality of the input ores.

Joe Carr, Industry Innovation Director of Mining at Axora

This could be particularly relevant in the sulphide space, for instance.

I did some work years ago on Pueblo Viejo for Barrick. When I was there, one of the things we were working on was blending the sulphides as we were feeding the mill from numerous satellite pits with very different sulphide grades. Because we were processing the ore with an autoclave, high-grade sulphides would cause a temperature spike and the low-grade sulphides would lower the temperature. This constant yo-yoing of the feed into the autoclave was terrible for the recovery of metals against the plan.

Generally, the old school way of blending is setting up stockpiles of ore based on whatever variable you want to manage at your operation. You would put a defined amount of each into the primary crusher on the understanding this would create a ‘blended’ feed for the processing plant.

With the information we have at our fingertips today, this process seems outdated.

You could, for example, use HoloLens or another VR system in tandem with the shovel operator to be able to see exactly what material he or she is excavating. That can then be linked back to the geological block model, with this material then tracked in the trucks and onto the run of mine stockpile, before heading to the plant.

This is where something like Machine Max comes in. Machine Max is a bolt-on IoT sensor that tracks where your trucks are in real time – where they have been and where they are going. The processing piece requires block model integration into a mine plan system. If you have the building blocks in place – the networking, sensors, additional infrastructure, etc – Machine Max could, when integrated with this model, allow you to attempt real-time ore tracking.

“If you have the building blocks in place…Machine Max could, when integrated with this geological block model, allow you to attempt real-time ore tracking,” Joe Carr says

The issue is not that the technology doesn’t exist, but that the mining industry hasn’t yet cracked putting all of this together at an industry-wide scale, available to all miners.

You can carry out a project like this or go totally the other way and have a machine-learning or artificial intelligence algorithm in the plant that is constantly reading the incoming feed. These could be based around the block model inputs, or a digital XRF solution, which is able to constantly tweak or adjust the plant settings to the feed specifications. Process plants are generally setup to handle one type of feed. This is usually only tweaked in retrospect or for short periods of time when the mine plan moves into a different mining horizon.

We also have a comminution solution that understands the feed coming in and optimises the mill and power settings to get the optimal grind for flotation, maximising recovery at the back end. While the input is typically set up to be grind quality and hardness for optimal flotation, there is no reason why you couldn’t configure it for, say, sulphides going into an autoclave, tweaking the autoclave heat settings dependent on the feed.

Once that system is set up, it becomes a self-learning algorithm.

Saving operational costs is another pain point for mining companies we always hear about.

We have a solution on our marketplace from Opex Group, which is looking to optimise production while reducing power. Coming from the oil & gas space, this AI algorithm, X-PAS™, offers the operator an opportunity to adjust the settings while still achieving the same required outputs. This is tied to CO2 reduction, as well as power cost reductions.

Opex Group’s AI algorithm, X-PAS, offers the operator an opportunity to adjust the plant settings while still achieving the same required outputs

In mining, the plant is your largest drawer of power, hands down. Generally, if it is not powered on the grid, it is powered by diesel. Opex Group’s solution can save up to 10% of power, which is a significant amount of fuel and CO2.

The solution reads information from your pumps and motors, analyses the planned output of your plant using all the sensor feeds, and tweaks the variables while sustaining the required output. The algorithm slowly learns how you can change configurations to reduce power, while sustaining throughput. This results in lower power costs, without impacting the output.

Importantly, instead of automating the process, it offers the saving to the operator sat in the control room. Operators, in general, are incredibly reluctant to pass over control to an AI algorithm, but when faced with such power saving opportunities, they will often elect to accept such a change.

And, of course, plant maintenance is always on the agenda.

This is where Senseye, which has been used in the car industry by Nissan and the aluminium sector by Alcoa, is useful.

Essentially, this provides predictive maintenance analytics. It is also a no-risk solution with Senseye backed by an insurance guarantee. It is sold on the basis that if you do not earn your money back within the first 12 months, you get an insurance-backed refund.

There could also be openings in the plant for Razor Labs’ predictive maintenance solution, which is currently increasing the uptime of stackers, reclaimers and car dumpers for iron ore miners in the Pilbara.

IM: When it comes to future comminution equipment design, do you expect digitalisation, wear liner innovations, or equipment design to have more of a bearing on operational improvements at mine sites? Phrased another way; is more emphasis being given to refining and extending the life of existing products with digital technologies and wear solutions, than the design of brand-new equipment?

JC: We believe there is always going to be a focus on retrofit and extensions. Once a mill is built, changing the equipment, upgrading, etc is very hard and time consuming. The logistics of getting a new SAG mill to site, for example, are mind boggling. New technology will always come for new sites, but most of the world’s mining capacity is already in place. I would expect most digitalisation to focus on two areas:

  1. Getting more and longer life from all the assets. For example, extending liner life, reducing operating costs and shortening downtime between refits; and
  2. Drawing insights from the existing asset with a view to sweating it. No mill ever stays at nameplate; there is always an increase in production. One or two percent more throughput can put millions onto the bottom line of a company. No mill wants to be a bottleneck in the cycle. In a mine there are always two goals: the mine wants to produce as much ore as possible to put the pressure on the mill, and the mill wants to run as fast as possible to put pressure on the mine.

When it comes to extending liner life, we have a solution worth looking at.

One of the companies we work with out of Australia has an IIoT sensor all tied to wear and liner plates. It is a sensor that is embedded into a wear plate and wears at the same time as the wear plate itself wears. It provides this feedback in real time.

So, instead of the standard routine changeout, it gives you real-time knowledge of what it is happening to these wear parts.

We have a great case study from Glencore where they installed the sensors for around A$200,000 ($152,220) and it saved several million dollars. The payback period was just weeks.

Where I want to take it to the next level is pairing the wear plate monitoring technology on chutes and ore bins and looking into SAG mills and crushers. Relining your SAG mill or primary gyratory crusher is a massive job, which takes a lot of time and cuts your productivity and output by a huge amount. Wear plates are made as consumables, so if you can use 5% less over the space of a year, for instance, there are huge cost and sustainability benefits. You can also more accurately schedule in maintenance, as opposed to reacting to problems or sticking to a set routine.

IM: When compared with the rest of the mine site, how well ‘connected’ is the comminution line? For instance, are gyratory crushers regularly receiving particle size distribution info for the material about to be fed into it so they can ‘tailor’ their operations to the properties of the incoming feed?

JC: Generally, not really. The newer, better financed operations tend to have this. Taking the example above, when designing a plant flowsheet, the close side settings are used. But are they updated on the fly to optimise the plant? Not really. Most processes are designed with a set number of conditions to operate at their maximum.

Most plants dislike, and are not set up to handle, variation in their system, according to Carr

Most plants dislike, and are not set up to handle, variation in their system. They like consistent feed quality and grade to achieve maximum recoveries. Over the next few years, the companies that develop the best machine learning or AI models to run plants in a more real time, reactive way will see the biggest growth. A mill will always say it’s the mine that needs to be consistent, but the nature of geology means that you can never rely on this. As one geologist I knew said, “geology, she is a fickle mistress”.

IM: Where within the comminution section of the process flowsheet do you see most opportunity to achieve mining company sustainability and emission goals related to energy reductions, water use and emissions?

JC: In terms of emissions, at Axora we are actively looking at technology that can help across the entire plant. There was a great paper published in 2016 around this specific topic ‘Energy Consumption in Mining Comminution’ (J Jeswiet & A Szekeres). The authors found that the average mine used 21 kWh per tonne of ore processed. Given diesel produces 270 g per kWh, this means a plant produces 5.6 kg of CO2 per tonne of ore processed, on average. For a 90,000 t/day site, this might represent 510 t of CO2 per day (186,000 t/y), just for processing. To put that into context, you would need 9.3 million trees to offset that level of carbon.

If the industry is serious about lowering its carbon footprint, especially Scope 1 and 2 emissions, then the focus has to come into the process. There are easy wins available from proven solutions in other sectors for companies that want to take them.

eHPCC: the future of grinding in mining?

A lot has been made of the potential of high pressure grinding rolls (HPGRs) to facilitate the dry milling process many in the industry believe will help miners achieve their sustainability goals over the next few decades, but there is another novel technology ready to go that could, according to the inventor and an independent consultant, provide an even more effective alternative.

Eccentric High Pressure Centrifugal Comminution (eHPCC™) technology was conceived in 2013 and, according to inventor Linden Roper, has the potential to eliminate the inefficiencies and complexity of conventional crushing and/or tumbling mill circuits.

It complements any upstream feed source, Roper says, whether it be run of mine (ROM), primary crushed rock, or other conventional comminution streams such as tumbling mill oversize. It may also benefit downstream process requirements through selective mineral liberation, which is feasible as the ore is comminuted upon itself (autogenously) in the high pressure zone via synchronous rotating components. Significant product stream enrichment/depletion has been observed and reported, too.

As IM goes to press on its annual comminution and crushing feature for the April 2021 issue – and Dr Mike Daniel, an independent consultant engaged by Roper to review and critique the technology’s development, prepares a paper for MEI Conferences’ Comminution ’21 event – now was the right time to find out more.

IM: Considering the Comminution ’21 abstract draws parallels with HPGRs, can you clarify the similarities and differences between eHPCC and HPGR technology?

MD & LR: These are the similarities:

  • Both offer confined-bed high-pressure compression comminution, which results in micro fractures at grain boundaries;
  • Both have evidence of preferential liberation and separation of mineral grains from gangue grains at grain boundaries; and
  • Both have an autogenous protective layer formed on the compression roll surfaces between sintered tungsten carbide studs.

These are the differences:

  • eHPCC facilitates multiple cycles of comminution, fluidisation and classification within its grinding chamber, retaining oversize particles until the target product size is attained. The HPGR is a single pass technology dependent on separate materials handling and classification/screening equipment to recycle oversize particles for further comminution (in the event subsequent stages of comminution are not used);
  • Micro factures around grain boundaries and compacted flake product that are created within HPGRs need to be de-agglomerated with downstream processing either within materials handling or wet screening. In some instances, compacted flake may be processed in a downstream ball mill, whereas, in eHPCC, preferential mineral liberation is perfected by subsequent continuous cycles within the grinding chamber until mineral liberation is achieved within a bi-modal target size (minerals and gangue). The bi-modal effect differs from ore type to ore type and the natural size of the minerals of interest;
  • The preferential liberation of mineral grains from gangue grains generally occurs at significantly different grain sizes, respectively, due to the inherent difference in progeny hardness. eHPCC retains the larger, harder grains, hence ensuring thorough stripping/cleaning of other grain surfaces by shear and attrition forces;
  • eHPCC tolerates rounded tramp metal within its grinding chamber, however does not tolerate high quantities of sharp, fragmented tramp metal that create a non-compressible, non-free-flowing bridge between roll surfaces, which risks the damage of liner surfaces;
  • The coarse fraction ‘edge effect’ common in HPGR geometry is not an issue with eHPCC. In fact, the top zone of the eHPCC grinding chamber is presumed to be an additional portion of the primary classification zone within the grinding chamber. The oversize particles from the internal classification process are retained for subsequent comminution;
  • The maximum size of feed particle (f100) entering the eHPCC is not limited to roll geometry as is the case with HPGRs (typically 50-70 mm). eHPCC f100 is limited to feed spout diameter (for free flow) and dependent of machine size ie eHPCC-2, -5, -8 and -13 are anticipated to have f100 60 mm, 150 mm, 240 mm and 390 mm, respectively. The gap between rolling surfaces is greater than the respective f100; and
  • eHPCC technology shows scientifically significant product stream enrichment.

IM: What operating and capital cost benefits do you envisage when compared with typical HPGR installations?

MD & LR: Both operating and capital cost benefits of the eHPCC relative to HPGR technology are due to the eHPCC not requiring the pre-crushing and downstream classification equipment required by HPGRs.

The eHPCC operating cost benefits are associated with eliminating maintenance consumables, downtime, reliability issues and energy consumption associated with the equivalent HPGR downstream equipment listed above.

The eHPCC capital cost benefits are associated with eliminating the real estate (footprint) and all engineering procurement and construction management costs associated with the equivalent HPGR upstream/downstream equipment listed above. eHPCC flowsheets are likely to be installed as multiple ‘one-stop’ units that maintain high circuit availability due to ongoing cyclic preventative maintenance.

IM: Where has the design for the eHPCC technology come from?

LR: It was invented in early 2013 by me. I then pioneered proof-of-concept, prototyping, design and development, culminating in operational trials in a Kazakhstan gold mine in 2020. A commercial-grade detailed design-for-manufacture has since been undertaken by a senior team of heavy industry mechanical machine designers and engineers.

IM: In your conference abstract, I note that the eHPCC technology has been tested at both laboratory and semi-industrial scale with working prototypes. Can you clarify what throughputs and material characteristics you are talking about here?

LR: The first iteration of the technology, eHPCC-1, was tested at the laboratory scale from 2013-2015. This proof-of-concept machine successfully received and processed magnetite concentrate, copper-nickel sulphide ore, alkaline granite, marble and a wolfram clay ore dried in ambient conditions. The typical throughput was between 200-400 kg/h depending on the feed size, particle-size-reduction-ratios (dependent of grain size) and target product size. The feed size was limited to a maximum of 25 mm to ensure free flow of feed spout.

Alkaline granite: eHPCC-2 coarse product (left) and fine product (right)

MD & LR: From 2016-2020, we moved onto the semi-industrial scale testing with the eHPCC-2 (two times scaled up from eHPCC-1). This was designed for research and development (R&D) and tested on magnetite concentrate, alkaline granite, and hard underground quartz/gold ore. The throughput capabilities depended on the geo-metallurgical and geo-mechanical properties of feed material, such as particle size, strength, progeny (grain) size and particle size-reduction-ratios (subject to confined bed high pressure compression). Larger-scale machines are yet to be tested against traditional ‘Bond Theory’ norms.

The eHPCC, irrespective of the outcomes, should be evaluated on its ability to effectively liberate minerals of interest in a way that no other comminution device can do. The maximum feed size, f100, at the gold mine trials was limited to 50 mm to ensure free flow through the feed spout. R&D culminated in pilot-scale operational trials at the Akbakai gold mine (Kazakhstan), owned by JSC AK Altynalmas, in 2020, where SAG mill rejects of hard underground quartz/gold ore were processed. The mutual intent and purpose of the tests was to observe and define wear characteristics of the eHPCC grinding chamber liners (roll surfaces). These operational trials involved 80% of the feed size being less than 17 mm and a variety of targeted product sizes whereby 80% was less than 1 mm, 2 mm, 2.85 mm and 4.8 mm. The throughput ranged from 1-5 t/h based on the size.

IM: What throughputs and material characteristics will be set for the full-scale solution?

LR: There will be a select number of standard eHPCC sizes. Relative to the original eHPCC-1, the following scale-up factors are envisaged: -2, -3, -5, -8, and -13. These are geometrical linear scale-up factors; the actual volumetric capacity is a cube of this factor, with adjustments for centripetal acceleration. Currently -13 times seems to be the maximum feasible size of the present detailed design philosophy, but there are no foreseeable limitations in terms of feed materials with exception to moist clay. Clay was successfully processed after drying the feed in ambient temperatures during testing. Further testing of moist clays blended with other materials that can absorb the moisture as they comminute would be desirable.

IM: Other HPGRs can also be equipped with air classification technology to create dry comminution circuits. What is the difference between the type of attrition and air classification option you are offering with the eHPCC?

MD & LR: Two modes of comminution occur in the particle bed of eHPCC repetitively and simultaneously. First, confined bed pressure compression breakage occurs at a macro level that promotes shear/compression forces greater than the mineral grain boundaries. Second, Mohr-Coulomb Failure Criteria (shear/attrition) that completes the separation of micro fractures on subsequent cycles takes place.

The nip angle between the rotating components of eHPCC technology never exceed 5°. During the decompression and fluidisation portion of the cycle, the softer species – which are now much smaller – are swept out of the fluidised particle bed against centrifugal and gravitational forces by process air. The larger species, influenced by centripetal acceleration, concentrate at the outer diametric and lower limits of the conical rotating grinding chamber, continuing to work on each other during each subsequent compression phase.

HPGRs are limited to one single-pass comminution event, requiring downstream external classification and subsequent recycling/reprocessing of their oversize and/or flake product.

IM: How will it improve the mineral liberation and separation efficiency compared with other grinding solutions that combine both?

MD: eHPCC technology could compete with the Vertical Roller Mill and Horomill, however, eHPCC is likely to be more compact with high intensity breakage events contained within the all-inclusive system of breakage, classification and removal of products.

IM: When was it most recently tested and over what timeframe?

LR: The eHPCC-2 pilot plant was mobilised, setup and commissioned in March 2020, but its operation was suspended until June 2020 due to COVID-19 quarantine restrictions and a need to cater to abnormal amounts of ball fragments in the feed, the latter of which pushed the treatment of tramp metal to the extreme. The machine operated for the months of June and July using liners constructed of plasma transferred arc welded (PTAW) tungsten carbide (TC) overlay. During this period, a total of 795 t was processed at various targeted product sizes, with, overall, an average throughput of 3 t/h (nominally 265 operating hours) processed.

Side view of pilot system including feed hopper and weigh-scale feeder (right), feed conveyor (middle foreground), control and auxiliaries (middle background), eHPCC-2 (left foreground), dust bag-house (left background) and product conveyor and stockpile (not shown left background)
Front-end loader filling feed hopper with SAG mill rejects f80 18 mm

The PTAW-TC overlay was deemed unsustainable as it was consumed rapidly and demanded continuous rebuilding due to the high pressure intensive abrasive wear on the convex cone. The pilot plant operation was mostly suspended during the month of August while an alternative tungsten carbide studded liner, analogous to HPGR studded rolls, was manufactured for simulating a trial of this studded liner philosophy. The studded liner philosophy was operated in the eHPCC-2 in Kazakhstan for sufficiently long enough to ascertain the creation of the autogenous protective wear layer of rock between the studs, with the simulation trial deemed a success. The design philosophy shall be adapted on the commercial-grade eHPCC.

eHPCC-2 TungStud™ as-new (left) high-pressure-air-cleaned (middle) and brushed (right)

The pilot plant was demobilised from the Akbakai site laydown area on September 10, 2020, to release the area for construction of a non-related plant expansion. The operational experiences of the pilot plant at Akbakai provided valuable knowledge and experience pertaining to mechanical inertia dynamics and design for eliminating fatigue within eHPCC components.

IM: Aside from the test work on trommel oversize at the Kazakhstan gold mine, where else have you tested the technology?

LR: eHPCC has no other operational experiences so far. Investment and collaboration from the industry to progress the commercialisation of eHPCC is invited. The commercial-grade eHPCC-2.2 is designed and ready for manufacture.

IM: Is the technology more suited to projects where multiple streams can be produced (fines, coarse piles, etc)?

LR: eHPCC is configurable to meet the demands and liberality of a diverse spectrum of feed materials and the potential downstream extractive processes are complementary to eHPCC product streams. Therefore, it would be incorrect to categorise it as more suitable in any one niche; it is configurable, on a case-by-case basis, to meet the liberality of the specific progeny of the feed.

IM: What energy use benefits do you anticipate by creating a one-step comminution and classification process over the more conventional two-step process?

MD & LR: The energy saving benefits include:

  • Elimination of tumbling mill grinding media consumption;
  • Elimination of the liberal wastage of randomly directed attrition and/or impact events that indiscriminately reduce the size of any/all particles (gangue or precious mineral) with the conventional tumbling mill; and
  • Elimination of energy consumption of the materials handling systems between the various stages of comminution and classification, be it dry belt conveying, vibrating screens, classifiers, cyclone feed pumps, cyclones and their respective recirculating loads that can be upward of 300% of fresh feed.

IM: Do you anticipate more interest in this solution from certain regions? For instance, is it likely to appeal more to those locations that are suffering from water shortages (Australia, South America)?

MD & LR: We suspect the initial commercialisation growth market to be from base metals producers seeking to expand or retire existing aged/tired comminution classification capacity, followed by industry acknowledgement of the technology’s potential to shift the financial indicators of other potential undeveloped projects into more positive territory. This latter development could see the technology integrated into new projects.

In general, the technology will appeal to those companies looking for more efficient dry comminution processes. This is because it offers a pathway to rejection of gangue at larger particle sizes, early stream enrichment/depletion and minimal overgrinding that creates unnecessary silt, which, in turn, hinders or disrupts the integrity of downstream metallurgical extraction kinetics, and/or materials handling rheology, and/or tailings storage and management.

LR: There are a number of rhetorical questions the industry needs to be asking: why do we participate in the manufacture and consumption of grinding media considering the holistic end-to-end energy and mass balance of this (it’s crazy; really why?)? Why do we grind wet? What are the barriers preventing transition from philosophising over energy efficiency, sustainability etc and actually executing change? Who is up for a renaissance of bravely pioneering disruptive comminution and classification technology in the spirit of our pioneering forefathers?

The more these questions are asked, the more likely the industry will find the solutions it needs to achieve its future goals.

Dr Mike Daniel’s talk on eHPCC technology will be one of the presentations at the upcoming Comminution ’21 conference on April 19-22, 2021. For more information on the event, head to https://mei.eventsair.com/comminution-21/ International Mining is a media sponsor of the event