World's Largest Suspended Electromagnet

Stony Creek, Ontario, Canada, January 1st 2010 - Dan Howes remembers the big pull. So powerful, it lifted a knife clean out of his pocket, zipped it through the air and smacked it up against the huge metal block on the factory floor.

"It was kind of funny," he recalls. "I was walking past it one time and had a utility knife in my back pocket. It took (the knife) right out of my pocket from about seven feet away."

World's Largest Suspended Magnet

Walker Magnetics General Manager, Brian Thwaites, proudly displays the World's Largest Suspended Electromagnet. At 88 tons, it weighs approximately 22 tons more than the current U.S. entry in the Guinness World Book of Records. It Also has approximately 270 tons of lifting capacity.

Howes had just felt the force of the world's largest suspended electromagnet. And its maker, Walker Magnetics National, thinks that should put the company into the records books ... as in Guinness records, the collection of fastest, biggest, and just about all of everything in the world. The Stoney Creek plant has notified Guinness of its record bid and is going through a verification process to get approval. A newspaper story is one step in the process.

There, it will hang above a conveyor belt and pull iron and steel material from copper-bearing ore flowing beneath. The ferrous objects could be anything from errant workers' tools to chunks of metal teeth ripped from machinery during mining operations.

The Walker magnet, about 22 tons bigger than the U.S. entry now listed by Guinness as the largest of its kind, has enormous power -- about 270 tons of lifting capacity.

Put somewhat more visually, that is the equivalent of suspending 130 Ford Windstar LX minivans.
Electromagnets essentially consist of a conductor metal, such as copper of aluminum, wound around a steel core. Direct electrical current fed through the unit generates the powerful magnetic field. The magnet was tested at intervals during the manufacturing process. It was on one of those testing occasions that Howes happened to walk too close to the unit. He and other employees sported T-shirts yesterday indicating their part in the project.

"This is something we can be proud of," said fellow worker Bob MacInnis.

The stated requirements were to design and build a magnet capable of removing large ferrous particles from copper ore which has been crushed to 10" (254mm) in size.

"This is something we can be proud of"

said fellow worker
Bob MacInnis

The capacity as specified was to treat 8400 metric tons per hour from a 3150mm (124") wide feeder. Conveyor raveling at a speed of .33 meters per second (65 feet per minute). The load height or depth of material on the conveyor is estimated to be 1600mm (63").

The magnet will be suspended over the end of the conveyor where the material is estimated to be 254mm (10") thick. The magnet is to be installed at an elevation of 10,000 ft. (3050 meters) above sea level at a copper mine located in Chile.

Since the feeder conveyor carries a uniform depth of material between the side skirts confining the material, the magnet was designed to provide a magnetic field to match this width.

Special Truck

This WALKER Magnet, weighing in at 88 tons, is the World's Largest Suspended Electromagnet. The truck carried in its own sections, and was assembled on-site at Walker National, Canada. The magnet was then loaded with Special Heavy-Duty Hydraulic Jack Lifts onto the carrier. The "Big Rig" specifications: 136 feet long from end-to-end ... a total of 12 axles ... and 50 wheels.

To accomplish this, the magnet designed with copper coils had to be wider than the feed conveyor and large enough in the direction of conveyor travel to produce the field strength at the suspension distance to remove the large particles.

The magnet is 3505mm (138") wide by 3048mm (120") long and nearly 2438mm (96") high and weighs 88.5 tons when filled with transformer oil to dissipate the hear generated by the coil.

The unit contains some 40,000 lbs. of conductor, some 24,000 lbs. of transformer oil, and 113,000 lbs. of steel and manganese. It surpasses the previously designated World's Largest Suspended Magnet by nearly 22.5 tons.