The suspension electro magnet separates tramp ferrous metal prior to a metal detector
Atherton materials handling has installed Bunting suspension electro magnet in Melton, UK, on its calcium carbonate quarry to remove tramp ferrous metal prior to a metal detector. This reduces the amount the metal detector has to be used and therefore increases productivity.
Magnetic separator manufacturer Bunting was contacted by Atherton as the metal detector was being activated too frequently. Bunting’s technical sales engineer, Tom Higginbottom, visited the site to review the installation along with the Atherton team.
The original metal detector, a model TN77 series, was supplied by Bunting and identified tramp metal that could cause damage to crushers, screens, and conveyors. The quantity of metal contamination caused the metal detector to frequently trip leading to the conveyor being stopped often to remove the metal, reducing productivity.
A suspension magnet was suggested to be added prior to the metal detector to remove tramp ferrous metal which is magnetic. This leaves the metal detector to identify remaining non-ferrous tramp metal.
Tom Higgingbottom said: “We worked closely with the Atherton material handling team to find a solution for their client. The final solution not only maintains and improves important protection against tramp metal damage, but also makes it easy and safe to operate and clean the suspension electro magnet.”
Materials were transported in a 100mm deep and 600mm wide troughed conveyor, making a suspension electro magnet suitable due to its strong, deep field which is powerful enough to attract tramp ferrous metal from the bottom of the burden.
Weighing just over a tonne and cooled by oil, the model 60 OCW 20 was selected. It is wider than the conveyor, being 925mm wide and 925mm deep. This grants a large amount of dwell time under the magnet for ferrous tramp metal to be pulled out by the force.
Three suspension points connect the electro magnet to a hand-geared travelling trolley, allowing it to move away from the conveyor for safe and effective removal of all captured tramp ferrous metal from the magnet face.
During operation, the maintenance crew can move the electro magnet over a chute before deactivating the magnetic field, allowing the metal to discharge from the magnet face to fall into a separate collection area.
Generating 650 Gauss on the belt surface, the electro magnet is suspended 200mm above the conveyor. The installation will result in a reduction in metal detector trips, reducing production downtime without harming the crushers and other equipment.
