Bunting's permanent crossbelt magnets are among the most popular magnetic separators we offer. These magnets work by positioning a permanent magnet block between two pulleys, with a self-cleaning belt rotating around them. Installation is straightforward—just mount the crossbelt magnet above a conveyor carrying materials. When ferrous metal enters the magnetic field generated by the crossbelt magnet, it gets lifted and separated from the rest of the material flow. Common uses for crossbelt magnets include mines, quarries, recycling centers, and food processing facilities.

Historically, crossbelt magnets were predominantly made using ferrite magnets, which are robust and cost-effective. To assemble these, ferrite magnet slabs or blocks are placed inside a stainless steel casing, then magnetized to create a magnetic field. More recently, rare earth crossbelt magnets have become available alongside traditional ferrite versions.

What Is a Rare Earth Crossbelt Magnet?

Unlike ferrite magnets, rare earth crossbelt magnets utilize high-strength neodymium iron boron magnet blocks. Unlike ferrite magnets, which are magnetized post-assembly, rare earth magnets are "charged" during the assembly process itself, meaning they're already magnetic when put together.

Rare earth crossbelt magnets were created to address the need for a lighter yet stronger alternative to ferrite crossbelt magnets. Industries like mobile crushers and screening plants particularly benefited from these innovations. At first glance, it might seem like rare earth crossbelt magnets are always superior due to their enhanced strength and reduced weight. However, they do come with certain limitations compared to ferrite magnets.

Potential Challenges with Rare Earth Crossbelt Magnets

It's true that "stronger isn't always better," especially in the world of crossbelt magnets. While operating, rare earth crossbelt magnets may present some drawbacks when compared to their ferrite counterparts, including:

A limited magnetic field:

Some rare earth crossbelt magnets have relatively shallow magnetic fields, projecting only a short distance below the magnet block and into the conveyed material. Even though these magnets might have more strength, their reach is shorter. This means that rare earth crossbelt magnets need to be positioned closer to the surface of the conveyed material, which isn’t always feasible, especially in applications involving large material surges.

Intense magnetic pull on the surface:

Rare earth crossbelt magnets exert a very strong magnetic force directly on the surface of their magnetic block. While this can be beneficial for smaller contaminants, it can cause issues when dealing with larger tramp metals. In some cases, the magnetic attraction is so strong that the metal cannot be automatically removed by the self-cleaning belt. This could lead to damage to belts, bearings, and motors. Manually removing such large pieces can also pose significant health and safety risks.

Which Crossbelt Magnet Should You Choose?

This article isn't meant to discredit rare earth crossbelt magnets. They are indeed an excellent choice for many applications. For instance, if the conveyed material has a consistent and shallow burden depth, rare earth crossbelt magnets can be placed closer, allowing for better separation of smaller contaminants.

Similarly, if the metal contamination in the material is smaller in size, rare earth crossbelt magnets often provide superior separation. However, it's important to consider other magnetic separator designs, such as pulley magnets or drum magnets, depending on the specific requirements of your application.

In general, if the tramp metal being handled is larger, the traditional ferrite crossbelt magnet tends to be the better option.

Still unsure which magnet is right for your needs? We're here to help! Our team of magnetic experts is ready to assist you in finding the perfect crossbelt solution tailored to your requirements.

For more information, feel free to reach out to Bunting today.