Tag Archives: Kittilä

Procon laying the change management groundwork for mining tech adoption

Canada-based Procon has been implementing tried and tested technology for its employees and end customers for decades, resulting in improved operational safety and productivity outcomes.

It is now looking to make the leap and adopt new solutions from the mining technology sector, according to CEO John McVey, with the contract miner already into “phase three” of an “Industrial Supervisor training program”, focused on Procon’s front-line supervision and incorporating change management associated with this adoption.

Speaking to IM on the side lines of the HxGN LIVE Global 2023 event, in Las Vegas, and ahead of his panel appearance on Wednesday (in a panel titled ‘Down Under: Standing Up to the Challenges of Underground Mining’), McVey said the established contract mining model needed to change to accelerate the uptake of new technology in the market.

“Inherently when we bid for work it has to be competitively tendered in order to try and win a new contract,” he said. “You aren’t typically able to add many bells and whistles on if you want to win the work.

“This likely has to change at some point, with mining companies understanding the benefits that come with rolling out and applying these new technology ‘bells and whistles’.”

Procon has seen glimpses of an evolution – McVey references the introduction of battery-electric trucks at the Brucejack mine in British Columbia, Canada, where Procon is working, plus the use of autonomous load and haul equipment at the Kittilä operation in Finland (where Procon previously carried out shaft work) – but he said that today these were the exception, not the rule.

“Where we may also see more mining technology being adopted in the future is with these junior developers striving for higher ESG (environmental, social and governance) goals,” McVey said. “These clean, green metal developers – due to these ESG aims – are often backed by different types of investors that are less risk averse, or less tainted by the project capital and schedule blowouts experienced in previous commodity cycles.”

McVey’s appearance at HxGN LIVE Global 2023 this week is centred around finding out how the mining technology provider can help Procon’s workers and its clients underground, with safety- and productivity-led solutions coming high up the contract miner’s agenda.

“There is very rarely opposition to bringing in any initiatives that will enhance safety underground,” McVey said. “As a result, it is obvious to start here.”

When it comes to productivity, the company is interested in finding out how it could potentially deploy the Production Optimiser™ solution at certain sites. This advanced mining technology, developed by Minnovare, which Hexagon’s Mining division acquired last year, improves drill and blast efficiency and productivity in underground hard-rock mines by reducing collar deviation and, as a result, delivering superior setup accuracy at the collar. This increases the number of holes drilled to within tolerance at the toe, achieving optimum blasts and reducing dilution, according to Minnovare.

Production Optimiser has been deployed across the mining world, including at sites operated by contract miners Pit N Portal (owned by Emeco Group) and Barminco (part of Perenti).

In addition to productivity and safety, McVey is conscious the graduates coming through the pipeline that may enter the mining sector want to interact with the ‘new technology’ they have become accustomed to.

“They are used to playing computer games, interacting with apps and using technology on a daily basis,” he said. “If we are to encourage them to join the mining sector, we need to adopt some of this to increase our appeal.”

Here McVey mentioned the in-house development of an app, PSAFE, to log all incidents underground. This allows Procon employees to upload photos and reports in close to real time, to enhance reporting and analysis of these incidents.

“While a worker may be somewhat reluctant to write up a report after a long shift underground,” McVey said. “The app – which we are in the process of rolling out across all our sites – is enabling them to capture important information almost immediately, particularly ‘near-miss’ reporting which is critical in avoiding potential hazards and incidents.”

Again, this comes back to the change management piece that is so important to any new technology being adopted and used successfully.

McVey is hoping to learn from other mining companies and contractors at HxGN LIVE Global 2023 about how they are achieving ‘buy in’ from their employees for this new technology, to enhance Procon’s own change management processes and reduce the risk associated with applying new solutions at their sites.

Orica, Epiroc and Agnico Eagle carry out world-first development charging milestone at Kittilä

Orica and Epiroc, in partnership with Agnico Eagle Mines Limited, have successfully commenced live blasting with Avatel™ – the world’s first semi-automated wireless underground development charging solution at Agnico Eagle’s Kittilä mine in Finland.

The milestone brings to life an industry-driven concept that dramatically improves safety at the face, which is one of the highest risk activities in underground mining today, Orica and Epiroc say.

Avatel enables a single operator to prepare and wirelessly complete a full charging cycle from the safety of an enclosed cabin while offering the best available blast outcomes through the integration of Orica and Epiroc’s flagship digital, automation and blasting technologies.

The first successful blast was loaded and fired on November 22, 2022, comprising 61 Orica WebGen™ 200 Dev wireless primers and 295 kilograms of Orica’s Subtek™ bulk emulsion loaded to a development face at the Kittilä mine.

Orica Chief Technology Officer, Angus Melbourne, said: “Together with Epiroc and Agnico Eagle we are extremely proud of the team in creating a solution that keeps people out of harm’s way during what is considered one of the highest risk activities for underground miners around the globe.

“With Avatel, we can now effectively manage risk for the people who spend the most time every shift directly exposed to hazards at the development face while delivering all of the blast optimisation benefits that Orica’s flagship technologies bring. The combination of digital, automation and wireless blasting technologies and by partnering with customers and peers, we can continue to solve the industry’s biggest challenges across safety, productivity and sustainability, together.”

Sami Niiranen, President for Epiroc’s Underground division, said: “This is a true milestone achieved for our industry where Epiroc in partnership with Orica have led the way to safer underground operation. By building on our recognised solutions and advanced Rig Control System, Avatel paves the way to safe productivity for the mining industry.”

Jari Näsi, Development Manager – Kittilä Mine, Agnico Eagle, said: “We are proud to create history here at Kittilä where the first mechanised and wireless development blast was initiated. There is always some risk when working close to the face; being able to do this work safely and efficiently from the cabin is promising, and mechanising the process will give a better blasting result.”

The first commercial implementation of Avatel will take place at Newcrest’s Cadia Valley Operations from December 2022.

Orica’s hardware and software platforms converging for Mining 4.0

Orica’s corporate vision of “mobilising Earth’s resources in a sustainable way” is being further realised through a host of developments from its Digital Solutions and Blasting Technologies divisions, IM reports.

Those involved in charging operations could soon benefit from the launch of Orica and Epiroc’s Avatel™ solution, which, in combination with the WebGen™ wireless initiation platform, offers the ability to remotely blast a development face.

At the same time, the company is busy with the sustainable production of emulsion, the integration of geological orebody information to optimise energy use for blasting, and the expansion of downstream mineral processing tools.

Avatel

Avatel is a combination of state-of-the-art hardware and software solutions designed to mechanise the blasting process.

It includes Orica’s HandiLoader™ emulsion process body, Epiroc’s M2C carrier integrating an RCS 5 control system with Orica’s LOADPlus™ control system, a WebGen 200 wireless initiation system and an automated WebGen magazine. Epiroc has also incorporated onboard dewatering and lifter debris clearing capability, while Orica’s SHOTPlus™ intelligent blast design software is leveraged to deliver superior blasting outcomes, Orica says.

Orica and Epiroc’s advanced technologies integrated into the Avatel system

These components help eliminate the need for personnel exposure at the development face throughout the charging stage of the mining cycle, keeping personnel out of the line of fire, by substituting inherently high hazard manual tasks with a mechanised development charging solution.

A prototype Avatel unit is set to commence operations at Agnico Eagle Mining’s Kittilä gold mine in Finland in the next few months. This follows “alpha trialling” of the complete prototype unit at Epiroc’s Nacka test mine in Stockholm, Sweden.

Adam Mooney, Vice President of Blasting Technology for Orica, said: “Our goal for Kittilä is to expose Avatel to a real mining environment, putting the unit through its paces in an active mine where safety, productivity and reliability are core requirements for success.

“We will gain a practical understanding of how Avatel will fit in with and benefit the entire mining cycle, while also taking the opportunity to measure the blasting improvements possible through the combined use of electronic initiation timing and the precise blast energy control available with Avatel.”

A separate unit, meanwhile, will head to Newcrest Mining’s Cadia copper-gold mine in New South Wales, Australia, later this year, for the first commercial deployment. This is currently undergoing pre-delivery commissioning at Epiroc’s customer centre in Burnie, Tasmania.

Cyclo

Not too far away in Papua New Guinea, Orica has successfully commissioned a Cyclo™ emulsion technology unit, which has been running at a customer site for around two months, according to Mooney. The unit in question has treated in excess of 100,000 litres of used oil, he said.

Cyclo combines the company’s emulsion technology with used oil processing technology to transform mine-site used oil for application in explosives. To provide the tight quality control and regular testing required to manufacture emulsions with such inputs, Orica has partnered with CreatEnergy to develop a standalone, on-site solution to treat used oil.

Orica initially scheduled Cyclo for market introduction in late 2022, but it scaled and sped up development and production plans to support customers’ operations and curtail material disruptions brought about by COVID-19.

The first automated containerised used oil recycling system was commissioned in Ghana late in 2021, with the Papua New Guinea unit being the latest deployment.

Cyclo – containerised, automated used oil recycling service at a customer site in Ghana, Africa

A Senegal Cyclo debut is on track for July given the unit is already in country and connected into the emulsion plant on site, Mooney explained.

The company also plans to bring to market a Cyclo unit suitable for Arctic conditions by the end of this year, with the solution already under construction.

Data to insights to intelligence

Aside from hardware and sustainable emulsion solutions, Orica has recently signed an agreement with Microsoft Azure predicated on creating data-rich and artificial intelligence-infused tools that enable productivity, safety and sustainability benefits on site, with Raj Mathiravedu, Vice President of Digital Solutions, saying such a tie-up enables the company to think of the blasting value chain in a much more holistic manner.

“Orica Digital Solutions’ purpose is to develop and deliver a suite of integrated workflow tools to enable the corporate vision of mobilising Earth’s resources in a sustainable way,” he said. “A key attribute to delivering this workflow is the journey that we need to incorporate from data to insights to intelligence.”

Mathiravedu says the company is looking to go beyond the traditional solutions pairing software and IoT devices for a discrete product to – with the help of Microsoft Azure capabilities – building “answer products” focused on improving workflows.

“These workflows can benefit from understanding how geology within the orebody intelligence space can help us determine the optimised energy required for blasting in a real-time production workflow,” he said. “We have started this journey and are already delivering value to our customers by integrating workflows from orebody to processing.”

One example of this is the company’s FRAGTrack™ suite of solutions, devised to provide blast fragmentation data with auto-analysis capability.

Delivered as part of the company’s BlastIQ Digital Optimisation Platform, FRAGTrack is able to capture real-time fragmentation measurement data for optimising drill and blast operations, improving downstream productivity and tracking of operational performance.

Originally developed for measurements on both face shovels and conveyors, the solution was expanded earlier this year with the launch of FRAGTrack Crusher for automated pre-crusher fragmentation measurements.

FRAGTrack Crusher installation at Stevenson Aggregates

There are several vendors offering fragmentation measurement tools throughout the industry, but Mathiravedu says Orica’s solution can carry out such analysis consistently and accurately – day or night – in extremely dusty and dynamic environments like mining.

“The FRAGTrack image processing technology can handle extremely dusty and lighting-affected conditions beyond any solutions in the industry,” Mathiravedu said. “It is also able to learn and adapt to specific operational environments like the dumping habits of different truck operators using artificial intelligence technology. Together with the integration with fleet management systems, it can provide a fully autonomous and integrated measurement solution.”

On conveyors, the FRAGTrack solution can reliably measure fines with increased accuracy compared with conventional systems that leverage curve-fit algorithms, according to Mathiravedu, with the advanced image and 3D processing techniques providing the ability to measure fragments down to 5 mm in size.

The combination of FRAGTrack Conveyor and Orica’s ORETrack™ solution can provide not only particle size distribution information, but also critical information on ore grade and hardness for the milling operations in real time.

“The FRAGTrack platform architecture has been designed to be scalable to incorporate different sensor inputs along with its high-performance GPU compute capabilities,” Mathiravedu said, explaining that there could be further analysis solutions down the line.

Epiroc, Orica secure Newcrest Cadia trial for commercial Avatel charging system

Newcrest Mining is set to trial Avatel, a fully mechanised development charging system developed by Epiroc and Orica, at the Cadia operation in New South Wales, Australia, later this year, according to Tony Sprague.

Sprague, Group Manager, Directional Studies and Innovation at Newcrest, said this will be the first commercial trial of the Orica and Epiroc co-developed system anywhere in the world.

Orica and Epiroc, back in 2019, announced joint work on a semi-automated explosives delivery system, enabling safer and more productive blasting operations in underground mines. The companies said the partnership would “bring together the deep expertise and experience of two global industry leaders” to address the growing demand from customers mining in increasingly more hazardous and challenging underground operations.

Avatel includes Orica’s HandiLoader™ emulsion process body, Epiroc’s M2C carrier and RCS 5 control system, working with Orica’s LOADPlus™ control system and WebGen™ 200 wireless initiation system and automated WebGen magazine. Epiroc has also incorporated an onboard dewatering and lifter debris clearing system, while Orica’s ShotPlus™ intelligent blast design software is also being leveraged. These components help eliminate the need for traditional tie-ins and other physical wired connections from the charging cycle.

Orica has stated previously: “This first-of-its-kind innovation enables a single operator to prepare and charge explosives from the safety of an enclosed cabin, several metres from the face and out of harm’s way. Combined with Orica’s LOADPlus smart control system and Subtek Control bulk emulsion, customers can enjoy complete and repeatable control over blast energy from design through to execution.”

Trials with a prototype machine have been taking place at Epiroc’s Kvantorp Underground Test Mine in Sweden under controlled underground conditions. IM understands there are also plans for a machine to head to Agnico Eagle’s Kittilä Mine in Finland to complete extended underground trials in the production environment.

Newcrest’s Cadia operation is set to be the first site to trial the complete commercial offering at Cadia, commencing in the second half of 2022, according to Sprague.

Agnico’s Kittilä clocks up full year of autonomous haulage with Sandvik

Agnico Eagle’s automation journey at the Kittilä gold mine in northern Finland has recently seen the operation run a full year of autonomous truck haulage using Sandvik’s AutoMine® system.

The operation has been using the AutoMine automation system for Sandvik loaders in production for several years, but the autonomous truck haulage fleet milestone is more recent.

Kittilä, the largest gold mine in Europe, uses AutoMine on its Toro™ TH663i truck to keep running as long as possible. It is loaded by an autonomous Toro LH621i up to surface dumping.

Jari Kolehmainen, Production Manager at Kittilä Mine, said: “Nowadays our miners can monitor the machines’ operation and autonomous production cycles from the comfort and safety of the control room. The mine’s productivity and safety have increased, and we are excited to see what the future will bring, as we know that there is even more potential to be gained with Sandvik’s cutting-edge technologies.”

Back in February, Agnico said production in the December quarter came in around 6,000 t above forecast thanks, in part, to improved fleet management and an increased usage of automation. It said the operation had been testing autonomous trucks and tele-remote equipment and was targeting to achieve 50% of production drilling and 15% of hauling remotely in 2021.

Autonomous loading and hauling pays off at Agnico’s LaRonde, Kittila gold mines

Increased uptake of autonomous loading and hauling technology at the LaRonde (pictured) and Kittila gold mines has helped Agnico Eagle Mines post a record quarter of production for the last three months of 2020.

Payable gold production in the fourth quarter of 2020 was 501,445 oz at all-in sustaining costs of $985/oz, the company reported. This compared with 494,678 oz at an AISC of $1,039/oz in the prior-year period.

Homing in on LaRonde Complex (including the LaRonde mine and the LZ5 Mine), in Quebec, Canada, Agnico put the good performance at LaRonde – production of 105,729 oz during the quarter, down from 112,704 oz in the prior-year period when gold grades were 7.3% higher – down partially to the automation strategy that, the company said, had helped improve productivity and allow continuation of mucking activities during non-entry protocols related to seismicity.

In 2020, 13% of tonnes mucked from stopes at the LaRonde mine were carried out in automation mode and, in December 2020, a record 39% of the production mucking at the LaRonde mine was carried out from surface, which included 100% of the production mucking from the West mine area.

At LZ5, in 2020, 14% of tonnes mucked and hauled to surface were accomplished in automated mode with operators based on surface. This surpassed the 15% target the company had set. For 2021, it is expected 17% of the tonnage will be mucked and hauled remotely to surface and the production rate is expected to be sustained at around 3,000 t/d. “The LZ5 automation team will continue optimising the automated mining techniques,” Agnico said.

Agnico said the target for 2021 is to muck over 17% of the total tonnage for the LaRonde Complex from surface. The company said it is also carrying out work to perform production drilling using automation.

In a January presentation, Agnico stated that 10 LHDs and four trucks had been equipped with Sandvik’s AutoMine® system. Back in 2018, Sandvik announced that the LaRonde mine would become the first operation to use AutoMine with LTE communication network underground on a production scale.

To continue tailings deposition through the LaRonde Complex life of mine, Agnico is also constructing dry-stack tailings facilities, which are expected to be operational by the end of 2022. Dry stacking will help limit the footprint of the new tailings facility and improve the closure of the main tailings ponds, Agnico said.

Moving to Finland at the Kittila gold mine, the use of automation also paid off.

The company said Kittila continued delivering strong performance in the December quarter of 2020, with production above forecast by around 6,000 t. This also coincided with the commissioning of the expanded mill at Kittila, which is now ramping up towards the design capacity of 2 Mt/y.

The mine delivered a record full-year ore production of around 1.85 Mt in 2020, according to the company.

“This performance (in Q4) is driven by an improved fleet management and an increased usage of automation,” Agnico said.

Kittila has been testing autonomous hauling trucks and tele-remote equipment and is targeting to achieve 50% of production drilling and 15% of hauling remotely in 2021, it said.

On top of this, Agnico said the mill had consistently increased availability and the company was evaluating the implementation of advanced process control in 2021.

Robit to supply drilling consumables to Agnico Eagle’s Kittilä gold mine

Robit and Agnico Eagle have signed a long-term cooperation agreement for drilling consumables supply to the Kittilä gold mine, in Finland, with the deliveries to start on May 1, 2021.

The company previously supplied diamond button bits to Kittilä mine for production drilling, thus, the mine and conditions are familiar to Robit, it said.

Tommi Lehtonen, CEO of Robit Group, said: ”We are happy to start this cooperation, which is a result of a long-time work and is an important reference to the company. It is also an investment in the domestic market. We are excited of this collaboration, which, in addition to product supply, offers an opportunity to develop our products together with one of the leading mining companies.”

Jari Kolehmainen, Production Manager at Kittilä mine, Agnico Eagle Finland Oy, added: “We are delighted with this agreement and expect a long-term and close collaboration. Together we have an opportunity to develop drilling consumables, eg diamond button bits and Sense Systems products, to serve customer needs even better.”

Kittilä mine is the largest gold mine in Europe. It extracts annually about 1.6 Mt of ore, yielding about 7,000 kg of gold. At current production volumes, the mine’s known ore reserves are expected to produce gold until 2034.

Kittilä mine leverages SIMS electrification experience as Boltec E Battery units start-up

Having tested out Epiroc’s battery-electric vehicles over the past two years as part of the SIMS project, Agnico Eagle Finland’s Kittilä gold mine has now started up its own Boltec E Battery bolting units.

The European Union-funded SIMS project and the related field tests of Epiroc’s battery-powered mining machines turned the eyes of the mining world to Kittilä, in northern Finland.

As part of the project, which took place during 2017–2020, Epiroc’s ‘green machines’ – the Boomer E2 Battery, Scooptram ST14 Battery and Minetruck MT42 Battery – were put through their paces.

Andre Van Wageningen, Manager of Technology and Development at the Kittilä mine, said: “The collaboration with Epiroc has been great and Epiroc has taken away all the concerns we had regarding battery-electric equipment. I believe that we also have supplied a very good test site.”

Tommi Kankkunen, General Manager of the Kittilä mine, added that the benefits with battery-electric equipment are obviously the reduction of fossil fuels and the reduction of carbon footprint, but also major advancements made to health and safety for its employees.

After the tests, the mine purchased its first battery-powered rigs, Boltec E rock bolting rigs selected as the first battery-powered units in line with the mine’s investment plan. The important drivers behind the decision were sustainability of the rigs and the opportunity to create a better work environment, according to Epiroc.

The first bolting rig arrived at the Kittilä mine in early November, with another similar bolting unit joining the club a couple of weeks later.

According to Jari Kolehmainen, Production Manager at Kittilä, the first messages were very positive: “The performance of the machines is at least at the same level as that of diesel machines. Productivity has improved with the development of equipment.”

The arrival of this new equipment will also benefit operators’ wellbeing at work as exhaust fumes, heat, vibration and noise have decreased.

“For example, a rock bolting rig is moved several times during a shift, and, in the past, it has always meant starting diesel engines and blowing up an exhaust cloud,” Epiroc said.

Also, in terms of maintenance, the equipment lacks a large component (diesel engine), and, as a result, oil and filter changes are omitted. Also, for fire safety, the use battery-powered machines mark a step forward in the absence of hot surfaces of the diesel engine and moving oils.

Air quality improves piece by piece when diesel-powered equipment is replaced by battery-powered equipment, according to Epiroc.

Kolehmainen said: “Especially on the loading and haulage side, the change in air quality is clear. In the future, we want to reduce our carbon footprint and move towards zero-emission technology, as well as move forward in wellbeing at work.

“The SIMS project showed that battery technology has made great leaps forward.”

In terms of infrastructure requirements, the mine’s electricity network should accommodate the electrification of the equipment. Battery-powered machines also require a battery replacement location.

Epiroc added: “Agnico Eagle Finland’s Kittilä mine wants to profile itself also towards the introduction of other new technologies in addition to battery-powered equipment. A remote control room has been completed for the mining office, from which several machines are controlled simultaneously.

“Since the beginning of October, it has been a permanent turn for two people to operate mining machines remotely. The mine firmly believes that investing in new technologies will bring long-term benefits.”

New Metso Outotec Courier on-stream analyser could reduce gold losses

Metso Outotec is launching its next-generation Courier® 6G SL on-stream analyser for direct measurement of gold, platinum and other valuable metal concentrations from ore feed, concentrate, and tailings streams.

The new analyser enables accurate real-time elemental analysis measurement critical for establishing efficient process control to improve process stability and maximise recovery, it says.

It builds on the Outotec Courier 6X SL analyser with a more powerful X-ray tube and measurement channels optimised for direct on-line measurement of gold and other elements from calcium to uranium, the company says. This makes it particularly suitable for applications where gold is recovered with other metals such as silver or copper.

The system can measure up to 24 individual process streams – each with an individually adjustable measurement time – to ensure optimal measurement accuracy and sampling frequency in even the most complex polymetallic flotation circuits. It can also provide direct measurement of gold concentrations down to 0.2 g/t

The new next-generation on-stream analyser combines Wavelength Dispersive X-ray Fluorescence and Energy Dispersive X-ray Fluorescence technologies with a high-power X-ray tube for unparalleled measurement performance, Metso Outotec claims. It also features an automatic internal reference measurement for guaranteed stability under changing environmental conditions.

Lauri Veki, Metallurgist at Agnico Eagle’s Kittilä operation in Finland, said: “Agnico Eagle Kittilä has used the new on-stream analyser for flotation control and optimisation since October 2019. Measurement information provided by the Courier 6G SL has enabled more efficient control of the pre-flotation circuit and helped to reduce gold losses.”

Bunting ups the Electro Overband Magnet stakes for Agnico’s Kittilä gold mine

The largest Electro Overband Magnet ever built at the Bunting manufacturing plant in Redditch, England, is destined for installation at the Agnico Eagle-owned Kittilä gold mine, in northern Finland.

Over a 12-month operating period, the Overband Magnet will lift and separate damaging tramp metal from around 2.7 Mt of conveyed ore, protecting crushers, screens and other up-stream process plant, according to Bunting.

One of the world’s leading designers and manufacturers of magnetic separators for the recycling and waste industries, Bunting has European manufacturing facilities in Redditch, just outside Birmingham, and Berkhamsted, both in the UK.

The Electro Overband Magnet uses high-strength magnetic forces to lift and then automatically discard tramp ferrous metal present in conveyed ore, Bunting says.

“In operation, the large Electro Overband Magnet is suspended in a crossbelt orientation across the non-magnetic head pulley of a conveyor transporting mined ore,” the company explains. “Any tramp ferrous metal entering the deep and strong magnetic field is attracted to the face of the electromagnet and lifted up and onto the surface of a continuously-moving self-cleaning rubber belt.

“Reinforced and heavy-duty rubber wipers on the belt catch the captured metal, transferring it to the side and away from the conveyed ore. As the wipers move the ferrous metal out of the Overband Magnet’s magnetic field, it drops under gravity into a collection area.”

This latest Electro Overband Magnet is part of a major plant expansion and upgrade at Kittilä, Bunting said. This will see ore production go from 1.6 Mt/y to 2 Mt/y, with gold output expected to rise by 50,000 oz/y to 70,000 oz/y when completed.

When initially contacted, Bunting engineers worked closely with the mine operator to design a bespoke Overband Magnet for the difficult application, it said. Design considerations included the width of the conveyor, the volume of conveyed ore, and the size and shape of the tramp ferrous metal. With these details, the Bunting design team calculated the minimum magnetic field and force density for optimum separation using an in-house developed Electro Overband Magnet Selection program.

These criteria provided the basis for the design of the electromagnetic coil by the Bunting-Redditch engineering team.

The final design is a model 205 OCW50 Crossbelt Electro Overband Magnet, with the 17 kW electromagnetic coil, generating the strong magnetic field, cooled using recirculated oil. Efficient cooling of the electromagnet is critical as the magnetic force decreases proportionally to the rising temperature of the coil, Bunting said.

The Overband Magnet is 4.2 m long, 3 m wide and 2.2 m high, and weighs just over 13 t.

The Electro Overband Magnet is designed for positioning in a crossbelt orientation over the non-magnetic head pulley of a 1,600 mm wide conveyor, inclined at 12° and travelling at 0.75 m/s. The conveyed ore has a particle size range of between 70-400 mm, Bunting said, varying in conveyed capacity between 450-765 t/h (equating to 2.7 Mt/y).

“The tramp iron ranges widely in size and nature and includes steel rebar (2,400 x 20 mm diameter), cable bolts (600 x 15 mm diameter), steel mesh, and broken drill bits,” Bunting said. “With a maximum working gap of 600 mm (distance between the magnet face and the bottom of the ore conveyor), the Electro Overband Magnet is designed to lift and separate the tramp metal through a splayed burden of up to 500 mm. This requires a substantially deep and strong magnetic field and related force density.”

Adrian Coleman, General Manager of Bunting’s Redditch facility, said large mining projects, such as this, often require bespoke solutions.

“Over 40 years, we have gained considerable experience in designing and building large Electro Overband Magnets,” he said.

“However, this was the largest we have ever manufactured at Redditch, presenting many challenges, which were overcome. And the design and manufacturing process all took place during the COVID-19 crisis.”