Magnets. What’s the deal?

Magnets. What’s the deal?

The importance of magnets in the concrete recycling, construction, of demotion waste industries is not rocket science. (It’s a rock science!) Having the ability to efficiently sort through concrete rubble for rebar and other metal contaminates is necessary in order to generate a clean and useful final product.

Usually installed along the conveyors of a portable plant, the magnet is a valuable crusher component for separating rebar and other ferrous metal contaminates quickly and automatically from the concrete being crushed and recycled.

The two types of magnets.

Magnets come in two primary varieties in the crushing industry, electromagnet and permanent magnet.

Permanent magnets are as their name suggests permanently magnetized. They will remain magnetic for their entire service life and require nothing other than proper placement to begin to remove rebar or other ferrous materials that pass near them.

Electromagnets utilize an electric current to generate a magnetic field which attracts the rebar and other steel. However, when the power is removed, the magnetic field disappears. These magnets are usually more powerful than permanent magnets, but are frequently larger, more complex, and weigh substantially more.

In most applications, both types of magnets would be fitted with a reinforced belt that would allow material that was picked up by the magnet to be pushed away from the magnetic field and discharged via a chute into a scrap bin or pile for recycling or disposal.

Inline vs cross belt, what’s the difference?

The difference between an inline magnet and a cross belt magnet is that an inline magnet is positioned in line with the conveyor it is mounted on, usually at the very end of the conveyor at a transfer point to another conveyor. A cross belt magnet is situated perpendicular to the conveyor that it is mounted on.

In general, inline magnets are more efficient at removing rebar and other steel contaminants because the material is no longer weighed down against the belt when it is transferring to another conveyor, as it would be in cross-belt. That allows the steel to pull through the otherwise heavy rock and be collected by the magnet.

However, at times, plant or conveyor configurations preclude the ability to have an inline magnet at the end of a conveyor and a cross belt magnet is then used. For example, The RapiDeploy 500 and RapiDeploy 1000 plants feature an optional cross belt permanent magnet that can stay on for transport.

In-line Electro Magnet

Now that we understand the deal with magnets…


Which one is best for you?

The usefulness of each electromagnet depends on each unique operation. If a crusher is conveying heavy volumes of reclaimed concrete or is conveying material more quickly, it may be more practical to install an inline magnet. However, it may also be more practical to install a cross belt magnet in order to best fit the optimal layout of the crushing site and equipment.

Eagle Crusher offers both inline and cross belt magnet options. To learn more about which electromagnet option may best suit your operation’s needs, contact our service team. To order an inline or cross belt magnet for installation, contact our parts department