Tag Archives: magnetic separation

Bunting on the importance of Permanent Overband Magnet selection for mineral separation

Permanent Overband Magnets are commonplace in mines and quarries, removing tramp ferrous metal and protecting crushers, screens and conveyors against damage. However, there are many different designs of Permanent Overband Magnet, developed to suit specific applications, with an understanding of installation being key to selecting the right one.

Bunting is a leading designer and manufacturer of magnetic separators, eddy current separators, metal detectors and electrostatic separators. The Bunting European manufacturing facilities are in Redditch, just outside Birmingham, and Berkhamsted, both in the United Kingdom.

Bunting designed and built the first Permanent Overband Magnets in the early 1980s and has since supplied thousands to companies operating across the world, it says. Although the basic technology has not changed, advances in magnet materials and manufacturing techniques have significantly enhanced the ferrous metal separation performance.

Overband Magnets lift and automatically remove tramp ferrous metal from conveyed mined or quarried rock. The permanent design features a magnet block mounted in a frame, with two or four pulleys, and a revolving self-cleaning rubber belt.

In operation, mined or quarried rock is conveyed underneath the Overband Magnet, which attracts, lifts and then removes damaging tramp ferrous metal. The size and type of magnetic system (Permanent or Electro) is dictated by the conveyor width, depth of material on the conveyor and the nature of the tramp ferrous metal.

Permanent Overband Magnets are commonly found on mobile plant such as crushers and screens.

Bunting’s range of Permanent Overband Magnets includes four different models to suit different installations. The heavy-duty PCB model suits quarry and small mining operations, operating at suspension heights of up to 400 mm on conveyors between 300 mm and 2,000 mm wide.

The PCB-C compact and lightweight model suits mobile plant installations, such as crushers and screens, and operations where space is limited. The PCB-C operates at suspension heights up to 250 mm, above 600 mm to 1,500 mm wide conveyors.

For installations where the Overband Magnet is located in a difficult location for regular maintenance, Bunting designed the QBC quick-belt change model. As the model implies, the self-cleaning belt is easy and quick to change, reducing downtime. This model operates at suspension heights up to 300 mm on conveyors between 600 mm and 1,500 mm.

The Tri-Polar Overband Magnet produces a different shaped magnetic field with increased power. Although commonly heavier, the deeper magnetic field means that the suspension height of the Tri-Pole is higher, up to 400 mm. The shape and depth of the magnetic field makes this model better suited for the separation of smaller or long and thin tramp ferrous metal.

Bunting concluded: “Selecting the correct Overband Magnet, in terms of permanent or electro and the specific model, is dictated by the application. Bunting’s applications engineers assess the ferrous metal separation objective (ie the plant being protected); the nature of the tramp ferrous metal (ie shape, size, etc); and the conveyed rock (ie size range, burden depth). These criteria assist the team in selecting the optimum Overband Magnet for any given application.”

Metso brings scalability to magnetic separation process with MSPUs

Metso has introduced modular Magnetic Separation Plant Units designed to streamline the flowsheet selection process, boost recoveries and simplify operation.

Alex Lagerstedt, Vice President, Plant Solutions at Metso, said: “As the industry leader in mining process technology and modularity, we are excited to launch the Magnetic Separation Plant Units. Besides easy installation and maintenance, the scalable units have been designed to provide unrivaled selectivity, resulting in high recovery of fine and ultrafine particles.”

Compared with a traditional delivery, the modular plant units result in the earliest time-to-volume, according to Metso. Thanks to maximised pre-fabrication in a controlled workshop environment and minimised site work, installation is safer, faster and of better quality.

The Magnetic Separation Plant Units feature a flexible scope to meet the needs of the end customer or EPCM. Delivery includes proven technology for the entire magnetic separation circuit with in-house testing for equipment sizing and flowsheet design, and it can also include automation, installation and commissioning advisory, training, maintenance and service.

Metso’s advanced magnetic separation equipment portfolio consists of SLon® Vertically Pulsating High Gradient Magnetic Separators, Metso High Gradient Magnetic Separators, and/or dry and wet Low Intensity Magnetic Separators. Additionally, the plant units can be equipped with OKTOP® feed tanks, slurry pumps, hoses and valves, and coupled with process control systems and various ancillary products and sampling systems.

Peter Jansson, Product Manager, Magnetic & Physical Separation at Metso, said: “Metso’s High Gradient Magnetic Separator portfolio features a wide range of processing options for many particle sizes and applications, ranging from iron ore concentrates, rare earth ores, battery and industrial minerals to tailings recovery. Combining these magnetic separators into plant units results in flexible and efficient flowsheets.”

For the Magnetic Separation Plant Units, Metso says it can also provide an integrated service offering through its global network. The scope ranges from maintenance, modernisations & retrofits, process optimisation to spares and wears, training and Life Cycle Services.

The Magnetic Separation Plant Units are Metso’s sixth complete plant unit launch for concentrator plants. The previous launches include Stirred Mill and Horizontal Mill Plant Units, Flotation, Thickening and Filtration Plant Units.

ICL, Bunting-Redditch collaborate on new magnetic separators for Boulby mine

ICL is making significant upgrades to its magnetic separators at the Boulby mine in North Yorkshire, England, with the company having decided to replace an existing single air-cooled Overband Electromagnet with four modern ElectroMax Overband Magnets that have been designed and built by Bunting-Redditch.

The ElectroMax Overband Magnets are a major improvement over the previous model, providing a more efficient and effective way to separate magnetic materials from non-magnetic materials, according to Bunting-Redditch. This upgrade will help ICL improve its mining operations, resulting in higher quality minerals and a more efficient production process, the company says.

ICL Boulby is the largest employer in the East Cleveland and the North York Moors National Park and will continue to be part of the region’s economic and social landscape for decades to come. In 1968, ICL Boulby, then known as Cleveland Potash, started underground mining of potash and salt. By 2017, the mining company had mined 1 Mt of polyhalite at Boulby.

The project to upgrade the magnetic separators at Boulby started in May 2023 when Bunting’s Technical Sales Engineer, Tom Higginbottom, undertook an on-site review of the existing installation. Material transported on three feed conveyors converged onto one conveyor where the in-situ Overband Electromagnet, installed many years previously, was failing to capture some tramp ferrous metal including small bolts and heavy steel bars. The tramp metal damages processing equipment such as crushers and screens, resulting in significant repair costs and costly production downtime.

In operation, Overband Magnets sit over conveyors to magnetically attract and remove tramp ferrous metal from the mined material. A heavy-duty rubber belt rotates around two large pulleys mounted either side of the central electromagnetic block and transports captured ferrous metal away from the magnet face and into a separate collection area.

The underground location of the Overband Magnet meant any replacement had to be air and not oil cooled. Even the switchgear had to be oil-free.

Bunting’s applications engineers assessed the project and compared new designs of air-cooled Overband Magnets with the installed unit. At a suspension height of 450 mm, the new overbands would have over double the gauss, the unit of measurement of magnetic induction, also known as magnetic flux density. However, the force density factor, which relates to the rate of change in gauss and the ability to lift a ferrous metal part, was over four times higher.

Bunting’s engineers concluded that the optimum solution was to install four air-cooled ElectroMax-Plus Overband Magnets instead of a single large unit. Three of the ElectroMax-Plus Overband Magnets would remove tramp ferrous metal on the three feed conveyors, with the fourth replacing the existing Overband Magnet where the conveyors merged the material into a single stream.

The suspension height of all four ElectroMax-Plus Overband Magnets (model EMAX-X-140) is between 400 and 450 mm across a 1,400-mm wide conveyor belt. Each Overband Magnet weighs 3.3 t and measures 950 mm long, 1,641 mm wide (with the motor to drive the self-cleaning belt), and 764 mm high. The ElectroMax Overband Magnets also feature bearing rotation sensors, belt tracking switches and bespoke guarding.

Higginbottom said: “Working closely with the engineering team at ICL Boulby and understanding the application and installation was the key to determining the best solution.”

The order for all four ElectroMax Overband Magnets was placed in September 2023 with delivery agreed for January 2024.

MetsoOutotec-testing

Metso Outotec on the need for holistic testing

The Metso Outotec global network of testing, research and product development facilities covers the whole process flowsheet from comminution through separation, to filtration, refining and pyrometallurgical/hydrometallurgical processing.

It has centres all over the globe – in Australia, Brazil, Chile, Germany, Finland, Peru, USA and more – able to, the company says, offer extensive expertise and circuit simulation to a wide range of industries.

Metso Outotec’s research and testing services include evaluation of ore types, mineralogical characterisation, feed material testing, sampling, materials selection, analytical chemistry and flowsheet development.

To get a flavour of this extensive research and testing portfolio, IM spoke to Alan Boylston, Director, Process Engineering at Metso Outotec, and Rodrigo Grau, Technology Director – Minerals Processing at Metso Outotec, about the capabilities of two of the company’s facilities – York (USA) and Pori (Finland), respectively, while also touching on Metso Outotec’s global testing and research capabilities.

In 2022, the company announced a consolidation of its minerals testing services in USA into a single 5,500 sq.m facility in York able to eventually cover the full minerals value chain and support the mining industry worldwide. Pori, meanwhile, focuses on mineral technology, hydrometallurgical processes development, pyrometallurgy and ferroalloys technology and material technology. In other words, the company conducts laboratory and pilot test work, flowsheet development as well as validation and development of new technologies for the industry.

IM: Will the York facility now be seen as your ‘testing centre of excellence’?

AB: The York facility is a centre of excellence for testing, but we have many of these within the company. Our global presence, the knowledge and our expertise at each of these locations is one of the factors that sets us apart.

Each of our locations is a centre for excellence in its own field. Pori, for example, has extensive research capabilities, Sorocaba in Brazil focuses on comminution and beneficiation testing, while Lappeenranta Dewatering Technology Center concentrates on thickening and filtration. Each location is an integral part of our global testing offering. In addition to these, we have various facilities around the globe covering also aggregates and pyrometallurgical testing, research and development.

That being said, the effort we have made to expand the York Test Center gives us a much better advantage for research and testing in North America, compared to a few years ago. We can now do more pilot-scale testing, especially with equipment like our HRC™800e high pressure grinding roll (HPGR). We can also carry out pyrometallurgical testing, plus conduct magnetic separation tests. At some point in 2023, we also expect to add thickening and filtration testing to this remit. But this is a very high-level view of what we have to offer in the York location.

Metso Outotec has a global network of testing, research and product development locations

IM: Even with this consolidation in USA, are you expecting to collaborate with other global facilities when it comes to testing processes throughout the flowsheet?

AB: Yes, absolutely. For example, we have a project coming in right now where the sample was first in Tampere (Finland) for some crushing test work, before they split off a sample for us for grinding test work in York and then Pori is also receiving a sample for some broader mineralogy testing.

This speaks to why we are able to claim to have global capabilities. No matter the testing or research need, we are able to assist our customers to get the job done. This all goes towards one goal – the customer’s benefit.

IM: How do you see these testing capabilities interacting and benefitting from other modelling work you carry out in-house? For example, do you anticipate using these facilities and the likes of the Geminex digital twin in unison to offer clients physical and digital representations of flowsheet options?

RG: Modelling is very important for us. In each project we work on, modelling and simulation are at the heart. Here in Pori, we carry out flowsheet development and technology validation. One of the outputs of our work is to end with a simulation of an industrial plant. Going from that simulation into Geminex is just one more step we will be taking in the future.

AB: At the York lab, we are now moving to a SCADA-based system to run everything: when a sample comes in, it gets tagged and identified and we then automatically know what test to run. We have tablets to, for instance, setup all the parameters of a test for an HRC 800e. We can start and stop the test on that tablet and see the real-time information coming in as the test is being carried out. That data is also being stored for future use.

We’re undergoing a program right now to build out a database function where all the post processing of this data goes on in the background and can then be seamlessly integrated into things like our HRC simulation software. We are building the backbone to carry out that real-time digital twinning.

IM: Do you anticipate your global testing capabilities to lead to a higher uptake of Planet Positive solutions?

AB: With our customers having a huge focus on sustainability, I do. As an example, since we have had the pilot-scale HRC 800e available for testing, it has been fully booked. In 2023, we are preparing for a test plan where we could take the HRC product and go directly into a pilot Vertimill. Those are two Planet Positive approaches we are putting together in a single test plant to show how far we can push energy efficiency and media consumption reduction.

RG: I would definitely agree with Alan. And to add to that – for example at Pori, we do a lot of hydrometallurgical testing and piloting, and that is only increasing with the rising demand for lithium and other battery minerals. And our customers are really looking at how our equipment is reducing their carbon footprint and other sustainability benefits.

You will hear us say it time and time again, but this is definitely a trend that we are seeing at all of our facilities.

Metso Outotec testing and research capabilities cover the entire flowsheet – from comminution through the entire operation to pyrometallurgical/hydrometallurgical processing

IM: Will these expanded testing facilities also benefit your equipment and process R&D work?

AB: I think so. We built this lab to not just be a materials testing facility, but also a research hub, especially for grinding, but also for any other Metso Outotec business area needs. There is definitely a huge opportunity out there for us!

RG: And this rings true around the globe at all our facilities. For example, in separation, we have been testing the Concorde Cell™ flotation technology in Pori for a long time. And that is how we’ve approached development of a lot of our other innovations that go to market.

IM: How would you say industry testing requirements have changed over, say, the last five years?

AB: From our perspective, I am seeing more comprehensive test programs come through.

Instead of, say, one certain test, it is an entire test program with specific timings around evaluations and the ability to develop the flowsheet through the testing required. There is more collaborative designing of the flowsheet taking place through testing than there was five or 10 years ago.

RG: It is certainly more comprehensive now than it previously was.

For example, we carry out early engagement with our customers in Pori and start developing a flowsheet and evaluating the ore types.

The amount of material that is tested nowadays is much bigger than it was before. Obviously, it is not just limited to this example, because, as Alan mentioned before, we’ve got this connection between all our facilities to ensure our customers get exactly what they need from their testing program.

Also, our customers think about different drivers in the process very carefully and want that reflected in the test work. That could be more evaluation on the water they consume. They also look at the energy expended, on top of the expected recoveries and metal grades.

There is more emphasis on sustainability, even at these early stages, in addition to looking at how the ore types may change over time and what impact this will have on the processing requirements.

This is where our extensive simulation and modelling capabilities are leveraged for the biggest impact.

IM: Anything else to add?

RG: Pori and York are but a fraction of the expertise of the wider Metso Outotec research and testing portfolio; one that continues to expand in line with customer requirements. We don’t just cover mining, either – like our equipment offering, we provide research and testing services for the whole flowsheet.

And we are continually improving our capabilities in this space for our customers. So, stay tuned for the future and where we can take research and testing!

Eriez promotes Jaisen Kohmuench to COO position

The Eriez® Board of Directors has appointed Jaisen Kohmuench to the newly created position of Chief Operating Officer (COO), a role that will see Kohmuench manage all of the company’s major operations, including Eriez-USA, Eriez Global Flotation and Eriez international businesses.

Kohmuench, already within the Eriez corporate leadership team, will continue to work closely with corporate executives and functional leaders to ensure Eriez’s sustained strategic growth, the company said.

Over the past two decades, Kohmuench has made significant contributions to Eriez, steadily ascending in the organisation across multiple business areas and geographies. He served most recently as Vice President-International, a position he held for three years before accepting this latest promotion to COO.

Kohmuench earned bachelor’s, master’s and doctorate degrees in mining and minerals engineering from Virginia Polytechnic Institute and State University. He has spent the entirety of his career with Eriez, joining the company in 2000 as a Process Engineer.

Eriez President and CEO, Lukas Guenthardt, said: “From his earliest days in research and development, through his role managing the US Flotation group and later in an overseas assignment as Managing Director for Eriez-Australia, Jaisen has distinguished himself as a talented leader with tremendous financial and operational acumen. He has developed and directed immediate and long-term business plans and profitable growth initiatives across Eriez’ global magnetic, flotation and service operations sectors.”

Among his many notable career achievements, Kohmuench is credited as an inventor on more than a dozen patents and has authored numerous technical papers for prominent scientific and technical journals.

“With Jaisen’s guidance and the support of his highly skilled worldwide team, Eriez is well-poised to successfully propel our business into the future,” Guenthardt said.

Metso Outotec highlights magnetic separation expertise

Metso Outotec has introduced a magnetic separators portfolio that, it says, caters to a wide variety of applications with the separators’ flexible modular design enabling superior separation selectivity and improved recovery of fine and ultra-fine particles.

Metso Outotec High Gradient Magnetic Separators are designed to recover weakly magnetic material from non-magnetic matter and can be used for many applications including the processing of iron ores, rare earths and other weakly magnetic minerals, which are not normally treatable by ordinary magnetic separators.

The Low Intensity Magnetic Separators, which are designed to recover magnetic material from non-magnetic matter, are part of Metso Outotec’s Planet Positive product offering. The separators use physical separation and require no chemicals in the process. The Low Intensity Magnetic Separators feature modular design with several frames and process tank designs and use a common magnetic drum for ease of selection of the best machine for each individual application, the company says.

Metso Outotec’s offering also includes the SLon® Vertically Pulsating High-Gradient Magnetic Separator, which processes fine, weakly-magnetic minerals. The units are wet, high-intensity magnetic separators that use a combination of magnetic force, pulsating fluid and gravity to process minerals.

Jan Jirestig, Product Manager, Magnetic Separators, Metso Outotec, says: “We have a long history in magnetic separation, and we delivered the first separator back in the 1890s. Since then, we’ve developed and delivered thousands of magnetic separators worldwide. We are continuously developing our products, securing our position at the forefront of the magnetic separation industry.”

Primero completes WHIMS project at Fortescue’s Christmas Creek iron ore op

Primero Group says it has completed the construction of a Wet High Intensity Magnetic Separation (WHIMS) processing plant at Fortescue Metals Group’s Christmas Creek iron ore mine in Western Australia.

The plant is expected to improve product grade and mass recovery from the desands unit at the Christmas Creek Ore Process Facility #2.

The flowsheet is based on a simple and robust configuration, where wet screen undersize at a nominal -1 mm is treated in open circuit through a low intensity magnetic stage, followed by a vertical WHIMS stage to produce a concentrate stream and a tailings stream, which can be integrated with the existing process and auxiliary equipment. The vertical WHIMS project entails the redirection of the wet screen undersize stream from the existing scrubbing circuit to feed the brownfield magnetic separation plant.

“We can proudly say that despite the impacts of COVID-19 and the fast-tracked nature of the project, the plant was successfully delivered and commissioned in less than 12 months – meeting all safety and project key performance indicators,” the company said.

Primero put the project’s success down partly to the “enhanced opportunity for collaboration early contractor involvement (ECI) provides”.

It added: “A flexible approach to project development that ensures the needs of all project stakeholders can be met prior to detailed design and implementation in a lump sum engineering procurement and construction (EPC) environment. This constructive, relationship-based contracting continued throughout construction, commissioning and now operation – demonstrating the power of the ECI contracting model when coupled with Primero’s unique, vertically integrated EPC capability.”

Steinert to bolster sorting system test capacity in Pulheim

Steinert is to introduce additional sorting lines for mining and waste recycling at its new test and development centre in Pulheim, Germany, the company says.

The new lines are being installed in an effort to better achieve the company’s aspiration of “test before you buy”, allowing it to “respond with ever more accuracy to the sorting aims of extraction, purity and profitability for each sorting task”, Steinert said.

Steinert’s sorting solutions are used throughout the mining industry as a way of pre-concentrating material ahead of milling.

The metal sorting line of the new test and development centre will official go into operation on September 22. This milestone will be marked with a virtual event held on that day.

By opening the new building, the company is trebling its testing capacity, allowing it to be more flexible in responding to customer demands, it said.

“The processing sequence deployed in the sorting systems is the same as that used in a real industrial plant,” Peter Funke, CEO of the Steinert Group, said. “We are delighted that even more customers can try out our technology, from magnetic separators to sensor-based sorting systems, such as X-ray transmission, X-ray fluorescence and near-infrared (NIR),”

The research and development team is also moving to the same building in Pulheim, seven kilometres away from STEINERT’s headquarters in Cologne, allowing customers to derive even more benefits from the latest developments, the company said.

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.”

Bunting ups the mineral separation ante with ElectroStatic Separator

Bunting has launched a new separation device that, it says, significantly broadens the company’s separation capabilities, opening new opportunities for optimising mineral reserves.

The development of the ElectroStatic Separator comes in response to enhanced material separation requirements in the recycling, plastics and minerals industries, Bunting said.

It uses tungsten electrode wire to generate electrostatic charges to separate dry liberated particles, exploiting the difference in electrical conductivity between various materials in a feed material to produce a separation.

“The separation depends on a number of key material characteristics including conductivity, moisture content and size range,” Bunting said. “In many applications, often due to the fine particle size, the ElectroStatic Separator is the only technology that enables a separation (eg -2 mm granulated cable scrap).”

The technology also replaces less environmentally friendly separation processes such as froth flotation in mineral processing applications (eg separation of rutile from silica sand), according to the company.

In operation, the technology uses the difference in conductivity between insulators (eg plastics) and conductors (eg copper and aluminium) to obtain a separation on an earthed roll. A vibratory feeder evenly feeds a material mix onto the top of a rotating earthed metal roll, with the rotating roll transferring the material under an electrode bar inducing an electrostatic charge. Non-conductive materials (ie insulators) adhere to the earthed roll via an image force, while the conductors lose their charge quickly and, under centrifugal force, are discharged, according to Bunting. This enables a separation.

ElectroStatic Separators provide material segregation in plants processing minerals, producing plastics, and recycling secondary metals, the company says, with differences in conductivity found in recycled materials and minerals sufficient to enable excellent levels of separation.

“Indeed, this includes the separation of metals with different conductivity,” the company said.

The mineral processing industry commonly uses ElectroStatic Separators in conjunction with high intensity magnetic separators such as Bunting’s own Rare Earth Roll Magnetic Separator and Induced Magnetic Roll Separator, it said. This combined separation process is used when processing beach sands, for example.

The new separator is available as a single or double staged system in feed widths of 500 mm, 1,000 mm and 1,500 mm to suit a specific application.

The Bunting Centre of Excellence in the UK includes a laboratory-scale model of the new ElectroStatic Separator, according to the company.