The Different Magnets in Wire Processing

In this article, we are going to discuss magnets, their various applications in recycling, and how we incorporate them into nearly every system we build. We will go through the different types of magnets we use and explain their functions.

1. The Magnetic Head Pulley

The magnetic head pulley is the most commonly used magnet in our systems. It replaces a standard conveyor head-pulley with one that contains magnets inside. Here is how it works:

• How It Works:
  • As material climbs the conveyor, the magnetic pulley at the end attracts steel or ferrous items, pulling them down into a separate tray.
  • Non-ferrous materials, unaffected by the magnetic field, continue along the conveyor.
• Applications:
  • We use magnetic head pulleys in setups where material flows through a granulator or onto a conveyor.
  • This system effectively separates ferrous (AKA magnetic) and non-ferrous materials.

2. The Cross-Belt Magnet (Overband Magnet)

Another commonly used magnet is the cross-belt magnet, which is installed above the conveyor.

• How It Works:
  • The cross-belt magnet creates a magnetic field over the conveyor. As material passes underneath, ferrous items are pulled up to the magnet.
  • The magnetized material is moved away by the belt integrated into the cross-belt system and dropped into a separate collection area.
• Special Features:
  • These magnets often include a secondary, weaker magnet (we call it a carryover magnet) to further assist in directing ferrous material away from the conveyor below.
  • The conveyor section below the magnet is typically made from stainless steel to avoid accidental magnetization, which could interfere with material flow.

3. Magnetic Drum Separator

The magnetic drum separator is a versatile tool that operates in two primary configurations:

1. Underneath Configuration:
   • Material passes under the drum, and ferrous items are attracted upward to the drum’s surface.
   • The drum rotates, carrying the magnetic material to the top, where it is “thrown” into a collection bin, while non-ferrous material continues along its path.
2. Overhead Configuration:
   • Material falls directly onto the drum’s face. The magnetic drum separates ferrous items by holding them to its surface while non-ferrous materials drop away.
   • This method is less effective as ferrous items can entrap non-ferrous materials on the drum’s surface.

We prefer the underneath configuration because it minimizes the risk of ferrous materials trapping non-ferrous ones, as the jumping motion up to the magnet helps free the non-ferrous material.

Preventing Entrapment

A major concern when using magnets is preventing ferrous materials from trapping non-ferrous ones. Here is how we address this:

• Multiple Magnet Systems:
  • Using a cross-belt magnet before a magnetic head pulley helps remove larger ferrous items first, reducing the chance of smaller pieces being trapped later in the process.
  • Additional magnets can help further process the steel and liberate any trapped non-ferrous materials.
• Advanced Shredding:
  • For mixed materials (ex., steel with copper inside), further shredding might be necessary to fully separate the non-ferrous.

Applications in Larger Systems

In larger systems like meatball processing lines, steel is sent through an additional mill to ensure thorough separation of trapped non-ferrous materials. These setups are designed to maximize material recovery and efficiency.

Final Thoughts

Magnets are an essential component in non-ferrous processing systems, but their effectiveness depends on proper design and implementation. If you have questions or need help with your specific setup, do not hesitate to reach out—we are always here to help.