Metal Recycling : Boosted Metal Separation with ElectroMax-Plus Overbands at W Maw

Bunting is one of the world's leading designers and manufacturers of magnetic separators, eddy current separators, metal detectors and electrostatic separators. Bunting's European manufacturing facilities are located in Redditch, just outside Birmingham, and Berkhamsted, both in the UK.

W Maw Recycling has over 17 years' experience in the domestic and commercial skip hire sector. The company's fully licensed waste transfer station in Rotherham is open to domestic and commercial customers holding a current waste carrier's licence.

W Maw used two permanent overband magnets to recover ferrous metal from the waste at the transfer station. However, the difficult nature of the waste and the presence of larger and heavier ferrous metals, such as hammer heads and disc brakes, meant that the separation performance was not up to scratch. The inability to separate the larger and heavier ferrous metal resulted in costly and time-consuming damage to shredders and other process equipment.

Bunting's Technical Sales Engineer, Tom Higginbottom, visited the site to inspect the installation. The challenging application led to the selection of two ElectroMax-Plus overband magnets.

The ElectroMax and ElectroMax-Plus range of electromagnetic overband magnets are up to 185% stronger than equivalent permanent overband magnets and 25% lighter. The lightweight yet powerful design is ideal for applications where space is limited or extra separation power is required.

The two ElectroMax-Plus overband magnets operate with a self-cleaning belt that rotates around the magnet to transfer and automatically discharge the ferrous metal attracted to the face of the electromagnet. The ElectroMax-Plus uses a simple frame with the cleaning belt driven and guided by two pulleys instead of four (as used in larger standard electro-overvoltage magnets). The result is a significant reduction in overall weight and size. In addition, unlike other designs of electromagnets and suspension magnets, the coil of the ElectroMax-Plus electromagnet is air-cooled, eliminating the need for conservator tanks.

At the Rotherham plant, the two ElectroMax-Plus overbelt magnets are installed on different waste processing lines. The ElectroMax-Plus 120 is positioned over a 1.2 metre wide conveyor and the second ElectroMax-Plus 140 over a slightly wider conveyor with a 1.4 metre wide belt. Both are suspended 400mm above the surface of the conveyor.
Due to the harsh nature of the application, both ElectroMax overbelt magnets are fitted with reinforced belts. These reinforced belts protect the surface of the cleaning belt from puncturing and excessive wear.
The installation of electro rather than permanent overband magnets brought an additional benefit. During maintenance of the overband magnets or other parts of the plant, the magnets can be switched off. This improved safety and reduced the difficulty and time required to carry out basic maintenance on the overband magnets, such as changing belts or replacing motors.

The ferrous metal recovered by the ElectroMax-Plus overband magnets is sent to a local shredder for further processing and cleaning. “Since the installation of the ElectroMax-Plus Overband Magnets we are no longer experiencing significant damage to our shredders,” explained Tony Scarlet from W Maw. “The magnets are pulling out really heavy and awkward ferrous metal, that the permanent magnets could not touch. They are doing a great job.”