Metal Separation at IERC 2018

Bunting Exhibiting at 17th International Electronics Recycling Congress (17-19 January 2018)

IERC, the first major recycling event of 2018, is being held in Salzburg, Austria between the 17th and 19th of January.  For the first time, Bunting Magnetics will have a stand at the event.

During the 3 day congress, experts from around the world will discuss the latest issues facing the recycling world such as the Chinese ban on plastic waste imports and the continued drive towards electric vehicles.

Bunting Master Magnets at RWM17

Technology is always high on the agenda as new innovations make it possible to recover and separate an increasing number of valuable metals whilst reducing the amount of unusable waste.

Bunting has developed a wide range of Magnetic Separator technology.  Following the acquisition of Master Magnets in January 2017, Bunting is able to provide solutions to separate any metals.

Stainless Steel Separation

Stainless Steel becomes very weakly magnetic when bent or cut (as when passed through a shredder).  Bunting developed two new Magnetic Separators, the High Intensity Separation Conveyor (HISC), and the Stainless Steel Separation Conveyor (SSSC).  Both systems have ultra high magnetic fields that enable the attraction and deflection of Stainless Steel, enabling separation.  Production sized equipment was recently on display the RWM 17 exhibition in the UK.

Non-Ferrous Metal Separation

The Eddy Current Separator remains a vital part of any recycling process, separating and recovering non-ferrous metals.  Master Magnets have a number of Eddy Current Separator configurations enabling the separation of large and very small non-ferrous metals.  In 2017, Master Magnets manufactured and shipped a record number of Eddy Current Separators.  This is as a direct result of companies seeing their equipment’s superior separation capabilities.

General Ferrous Metal Separation

Separating metal at stages is the key to enabling the best recovery and purity of metal.  General Magnetic Separators are commonly used earlier in the process to recovery or remove ferrous metals and include:

Bunting Europe’s Managing Director, Simon Ayling, will be at the congress.  If you have a specific application, please see us on our stand.

In the meantime, for further information on Metal Separation or to assess the right Magnetic Separator or Metal Detector for a specific application, please contact us on:

Phone: +44 (0) 1442 875081
Email: sales@buntingeurope.com
Via the website

 

 

Getting Metal Out of Processed Vegetables

Ideal Locations for Magnetic Separators and Metal Detectors in a Vegetable Processing Plant

Processed vegetables are a vital part of the food chain.  Tens of thousands of bags of pre-cut carrots and freshly prepared kale are bought in supermarkets daily.  Frozen vegetables have been very popular since Clarence Birdseye invented the quick freezing method in 1924.  Also,  often-unnoticed processed vegetables are present in many everyday food items such as tinned soup, baby food, sauces, and ready-made meals.

However, processing vegetables takes a great deal of care and attention as the products are often delicate and can be easily damaged.

BUNT-2286 4 8.5x11 plants

As with all processed foods, there is always the risk of metal contamination.  Metal can be introduced at various stages in the process.  The design and positioning of the Magnetic Separator or Metal Detector has to also respect the delicate nature of the product.

Untreated Vegetables Feedstock

During the collection and transportation of the raw vegetables, there is always a high risk of metal contamination.  This can be remove using a Plate Magnet.  To avoid contact with the vegetables and eliminate the risk of damage, the Plate Magnet is suspended above the incline conveyor feeding the washer.  Metal is attracted up onto the face of the Magnet and held until cleaned.  This is ideal to remove larger metal items such as screws and nails.

Post Washing

The vegetables washing process frees dirt and other detritus including metal particles.  Prior to the washed vegetables being fed into a drier, a Permanent Magnetic Pulley, replacing the standard head pulley of a conveyor, attracts and automatically removes any free metal before entering the drier.  Again, there is no physical content between the Magnetic Separator and the vegetables.  After drying, the vegetables are fed into a dicing machine.

Prior to Dicing

Plate Magnet Tapered Step-9545
Plate Magnet Tapered Step

The blades on a dicing machine are delicate and expensive.  Metal contamination can cause significant damage.  To ensure that no metal is present, the dried vegetables are fed over the surface of a Plate Magnet.  This enables higher levels of separation that when the Plate Magnet is suspended as the material is passing closer to the area of maximum magnetic strength.  Any potential damage to the vegetables as they flow over the surface of the Plate Magnet is limited.  Metal is captured and then held under the lip of a tapered step on the surface of the Magnet.

Undersized Vegetables

Smaller sized diced vegetables are often taken on a different route.  They can be mixed with water, for ease of transportation, before being reintroduced into the process.  Immediately after dicing, the smaller particles fall through a Quicktron Metal Detector to remove any small ferrous and non-ferrous metals (including any broken blades from the dicer).  Water from the external source is passed through a Magnetic Liquid Filter Magnet to ensure that any rust or other ferrous metal contamination is not introduced into the process.  The Undersized Vegetables are mixed with the water and then re-introduced into the process.

Final Packed Product

Metron 05C Metal Detector
Metron Metal Detector

The final stage of weighing and packing includes 3 steps of Metal Removal and Detection.  Prior to weighing, the processed vegetables are passed over the surface of a Plate Magnet to ensure that all ferrous metal contamination has been removed.  After weighing, the vegetables fall under gravity through a Quicktron Metal Detector where any non-ferrous metals are removed.  Finally, after packing, the finished packed batch of processed vegetables are passed through a tunnel-type Metron C02 Metal Detector as a final check prior to shipment.

This is a typical example of a Vegetable Processing Plant.  However, each plant is unique and often a site visit is required to assess and recommend the best ways to ensure a metal-free end product.

For further information on removing Metal from Processed Vegetables using Magnetic Separators and Metal Detectors, please contact the Bunting technical sales team on:

Phone: +44 (0) 1442 875081
Fax: +44 (0) 1442 875009
Email: sales@buntingeurope.com
Web: http://www.buntingeurope.com

Other Food Plant Reviews include:

What is an Axial and Radial Magnetic Field?

Explaining Magnetic Separation

Rotary Magnetic Separators, such as the Bunting Drum Magnet and Magnetic Separation Pulley, are designed with a specific type of magnetic field.  The type of magnetic field has to be considered when looking at any application and when deciding which design will achieve a customer’s separation objective.

So what is an Axial or Radial Magnetic Field and why is it so important?

Axial Magnetic Field

Axial Magnetic Field Bunting Magnetics- Figure 1 – Axial Magnetic Field

This is when the magnetic field stretches across the width of the rotary Magnetic Separator.  Magnetically susceptible material entering into the field is attracted to the point of highest magnetic intensity (the pole) but is then dragged through an area of weaker field (between the poles) and onto another pole by the motion of the conveyor or drum.

This type of magnetic field is ideal when there could be a high level of entrapped non-magnetic material captured by the Magnetic Separator.  The motion of moving between the poles results in non-magnetic material being released as the magnetic item ‘tumbles’ in the field.  However, with this type of magnetic field there can be a reduced separation performance.

Radial Magnetic Field

Radial Magnetic Field Bunting MagneticsFigure 2 – Radial Magnetic Field

The Radial Magnetic Field has poles running in the same direction as the rotation of the conveyor or drum and with the flow of the material.  Magnetically susceptible material is attracted to the points of highest magnetic intensity (the poles) and held until it is dragged out of the magnetic field underneath the conveyor or Drum.

This type of magnetic field is ideal when the maximum level of separation is required, but there can be some carryover of non-magnetic material.  The fact that the captured magnetics always remain on the pole of highest magnetic intensity means that they are far more likely to be removed and, therefore, the radial design provides the best level of separation.

These types of Magnetic Fields are used in Magnetic Separators such as Magnetic Drums and Magnetic Pulleys.

For further details on the Bunting range of Metal Separation Equipment, please contact our technical sales team on:

 

Metal Found in Chocolate Eclairs

Sainsbury and Morrisons Remove Metal Contaminated Products from Shop Shelves

The announcement of a Food Safety issue at any major supermarket is always cause for concern.  The latest ‘metal in food’ safety announcement relates to chilled desert products, such as chocolate eclairs and profiteroles, supplied by Bakkavor to Sainsbury and Morrisons in the UK.

During the food manufacturing, it is widely accepted that metal will be introduced into the process.  The metal can arise from processing equipment (eg a broken screen, damaged pump) or from accidental introduction.  The metal can be ferrous, stainless steel or non-ferrous.

Ensuring that the metal is removed during the process or detected and removed as part of the final product is achieved by installing a series of Magnetic Separators and Metal Detectors.  Magnetic Separators are able to magnetically attract and hold ferrous metal and abraded stainless steel.  Stainless steel becomes weakly magnetic when work hardened (eg from wear) and can be attracted and held by strong Rare Earth Magnets in the form of Tube Magnets, Grate Magnets and Plate Magnets.

Tube Cartridge Magnets Bunting Magnetics-5

Commonly, Magnetic Separators are installed as the food is being processed and Metal Detectors are used towards the end of the process, often just before and after packing the food product.

As processes and products change, a regular review of the plant is required to check that the Magnetic Separators and Metal Detectors are located in the optimum position to capture any problematic metal.  This is often Magnetic Separation Audit with the findings recorded as part of the Quality and Safety Management procedure.

Other news articles discussing Metal Contamination in food include:

For further information on Magnetic Separators and Metal Detectors used to separate and detect metal in foodstuffs, please contact us on:

Phone: +44 (0) 1442 875081
Email: sales@buntingeurope.com
Web: http://www.buntingeurope.com

 

Misconception of Ferrous Metal Removal before an Eddy Current Separator

4th of 5 Misconceptions About Eddy Current Separation

This is the 4th in a short series of blogs discussing misconceptions about Eddy Current Separation.  Eddy Current Separators are used extensively throughout the recycling industry to separate non-ferrous metal (e.g. aluminium beverage cans, shredded aluminium and copper etc) from non-metallic materials.

Bunting Eddy Current Separator-5

All Ferrous Metal Need to be Removed

Despite the Eddy Current Separator being a separation system based on magnetic principles, there is often a question about whether it should be used to also remove ferrous metals.

In its simplest form, the Eddy Current Separator is a conveyor with a magnetic rotor acting as a magnetic head pulley.  Due to the laws of physics, the Magnetic Rotor will attract ferrous metal and so could be used to separate magnetically susceptible materials.  However, there are some limitations:

  1. With Eddy Current Separators that have Concentric Magnetic Rotors (ie the magnetic rotor spins uniformly within an outer non-magnetic shell), it can be difficult to discharge magnetic material from the belt. Due to the high speed rotating magnetic field, magnetic material that has not been discharged and remains vibrating at the bottom of the rotor can get hot and, when the conveyor belt stops, can burn through the plastic of the belt.  This can then damage the shell and the magnetic rotor;
  2. The Eccentric Magnetic Rotor design is more forgiving as the rotor sits in a corner quadrant of the non-metallic shell and so magnetic material leaves the magnetic field as it is pulley around by the conveyor. This ferrous metal is discharged underneath and often into the non-metallic fraction;

Successful metal recovery and separation is achieved by focusing on specific materials at key points in the process and this means removing as much ferrous metal prior to the Eddy Current Separator as possible.  This then leaves the Eddy Current to focus on separating non-ferrous metals from non-metallic materials.

Typically ferrous metals are removed and recovered prior to the Eddy Current Separators with:

Other blogs in this series on Misconceptions about Eddy Current Separation include:

For further details on the Bunting range of Eddy Current Separators, Magnetic Separators and Metal Detectors please contact Carlton Hicks (carltonhicks@buntingeurope.com) or our technical sales team on:

3 Types of Ferrous Metal Found in Plastics Recycling

Metal Removed by Magnetic Separators

Metal is a major cause of equipment damage, production downtime and poor end product quality, especially when recycling materials such as plastic.  So what types of metal can be found?  Here are 3 examples taken directly from a UK plastics recycling plant.

  1. Fine metal shards and even dust – The metal found on the face of this ultra strong Rare Earth Plate Magnet is quite fine and has been lifted up out of conveyed material.  Fine iron is difficult to separate and can cause significant wear to plant and also contaminate the final product.  In this particular installation, Plate Magnets were used both suspended above the conveyor and positioned in chutes (where material flows over the magnet face), but fine iron can also be removed using Drum Magnets;Fine_Iron_on_a_Bunting_Plate_Magnet
  1. Nuts, Bolts and Screws – This is a more typical example of metal contamination that tends to be either present in the delivered reclaimed plastic or introduced into the process from plant wear or during maintenance.  Nuts, blots and screws cause significant damage to process plant and can be costly in terms of equipment repair and production downtime.  In this installation, these ferrous metal items were removed from the product stream using a Magnetic Pulley although Drum Magnets are also used;Metal Found in Plastic Recycling Bunting Magnetics-2
  1. A Large Spanner – An extreme, but not unusual, example of metal contamination.  The damage that a tool such as a spanner can cause is huge in terms of cost and downtime.  Introducing a spanner into a shredder or granulator could have disastrous consequences.  The spanner in this photograph was separated using a Magnetic Pulley.  On other plants both Drum Magnets and Twin Pole Overband Magnets are commonly used;Metal Found in Plastic Recycling Bunting Magnetics-3

We are putting together a library of metal items that have been found in process lines and would welcome your feedback and photos.  Please send us your stories to press@buntingeurope.com and we will add these to this news blog on our website.

For further details on the Bunting range of Magnetic Separators and Metal Detectors please contact our technical sales team on:

Metal Recovery from Old Landfill Tips

Wheatway and Cotswold Recycling Use Bunting Magnets to Remove Steel from Old Landfill

A single Cross Belt Overband Magnet and five Magnetic Separation Pulleys supplied by Bunting Magnetics have been installed by Wheatway of Gloucester on mobile screens owned and used by Cotswold Recycling Company Limited, based near Bristol.  The screens are being used as part of a process to rework an old landfill site.

Cotswold Recycling has a two-year project for re-processing landfill on an old site near Reading, Berkshire.  The landfill originated from industrial and commercial waste and is being reworked and the area cleansed to enable the building of houses.  They are using a range of Powerscreen mobile screens to size and segregate the material.  Cotswold Recycling was established in 2001 and offer up-to-date crushing and screening equipment to hire or on contract.  Their equipment enables effective recycling, reducing costs and producing a re-useable product.

IMG-20130227-00025

The landfill site had approximately 400,000 tonnes of material that required processing.  Originally closed in the mid 1990’s, the site had been used for industrial and commercial tipping for over 15 years.

One issue facing Cotswold Recycling was efficiently removing any steel and ferrous metals from the material.  The company was already working closely with Wheatway, who specialises in providing engineered solutions and spares to the crushing, screening and recycling industry.  Wheatway was tasked with assessing the application and contacted Bunting Magnetics Europe Ltd.  Wheatway had previously worked with another magnetic separation manufacturer and decided to work with Bunting due to their excellent sales support and service.  Bunting proved to be flexible when working with Wheatway, something that was essential due to the nature of the project.

Initially, Wheatway designed a tower structure incorporating a Cross Belt Overband Magnet.  This was positioned between two screens and separated ferrous metals by lifting them off a 800mm wide connecting conveyor belt inclined at 30º.  The Bunting Cross Belt Overband Magnet was a twin-pole design, rather than mono-pole, resulting in a far superior level of separation.  Although there was an excellent level of separation, Wheatway then considered how to make a more flexible and mobile solution as the mobile screens were constantly being repositioned.  Wheatway contacted Bunting and then purchased five Magnetic Pulleys, one for each of the mobile screens.

The Magnetic Pulleys replaced the head pulleys of the conveyors on the output of the screens.  Bunting manufactured the Magnetic Pulley by mounting strong permanent ferrite magnets onto a steel carrier that is then encased by a tightly fitting stainless steel shell.  The magnets produce an axial magnetic field that rotates with the normal motion of the pulley.  This enables entrapped material to be freed and reduces the carryover of non-magnetic material into the reclaimed ferrous metals.  The Magnetic Pulley is a simple and very effective way to separate ferrous metals, especially when the particle sizes are below 50mm and can be designed to be retrofitted on most conveyors.

MP2

For the installation, Wheatway designed a stainless steel splitter plate, which was then bolted onto the existing framework without any need for any additional holes or modification of the screen frame.  All the screened material would then pass up the belt and any ferrous metals would be attracted to the pulley and discarded under the pulley, whilst all non-magnetic materials continued to cascade under a normal trajectory out and away into a separate pile.

Wheatway designed the retrofit to ensure that there was no reworking of the framework and utilised existing holes and fittings.  This meant that a team of three people, including Colin Smith of Wheatway and Richard Cooper of Cotswold Recycling, was able to install all the magnetic pulleys and the chutes in one day.

Each Magnetic Pulley is fitted underneath a 900mm wide conveyor belt carrying approximately 50 tonnes per hour of minus 40mm material and, depending on the area of the landfill being processed, removes up to 5% magnetics.  The magnetics are then passed on for further processing to recover, clean and reuse the steel and other ferrous metals.

Richard Cooper of Cotswold Recycling commented on the Bunting equipment, stating, “The magnetic pulleys are very good and are working remarkably well, especially considering what’s going over them.”

Bunting Magnetics design and manufacture a wide range of Metal Separators for the recycling industry and will be at the RWM exhibition at the NEC in Birmingham in September.

For further details on the Bunting range of Eddy Current Separators, Magnetic Separators and Metal Detectors please contact Carlton Hicks (carltonhicks@buntingeurope.com) or our technical sales team on: