ElectroMax Plus Overband MagnetICL Boulby is making significant upgrades to its magnetic separators at its mine in North Yorkshire. The company is replacing 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. This upgrade will help ICL improve its mining operations, resulting in higher quality minerals and a more-efficient production process.
Bunting-Redditch is a trusted and experienced provider of magnetic solutions, and its expertise in designing and building the ElectroMax overband magnets will ensure that ICL’s upgrade is a success and demonstrate that ICL is taking a proactive approach to improving its mining operations which will help ensure it remains competitive in the marketplace.
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 one million tonnes of polyhalite at Boulby.
The project to upgrade the magnetic separators at Boulby started in May 2023 when Tom Higginbottom, Bunting’s technical sales engineer, 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 ago, 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 expensive repairs and 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.
Pictured right: ElectroMax-Plus with an armoured beltThe underground location of the overband magnet meant that any replacement had to be air and not oil-cooled and 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 450mm, 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 overband magnets would remove tramp ferrous metal on the three-feed conveyors, with the fourth replacing the existing overband where the conveyors merged the material into a single stream.
The suspension height of all four overband magnets (model EMAX-X-140) is between 400 and 450mm across a 1,400mm-wide conveyor belt. Each overband weighs 3.3 tonnes and measures 950mm long, 1,641mm wide (with the motor to drive the self-cleaning belt), and 764mm high. The magnets also feature bearing rotation sensors, belt tracking switches, as well as bespoke guarding.
Tom Higginbottom, Bunting’s technical sales manager, concluded: “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.