When you think of magnets, one of two images probably comes to mind: a little circle you place on the outside of your refrigerator or a big red horseshoe-shaped piece of metal that practically drags its holder to the nearest piece of metal. Of course, there’s more to magnets than domestic life or cartoon characters. Heavy industries rely on powerful magnets for a variety of processes, as a closer look at just a few of these industrial applications of magnets will indicate.
Magnets and metal go hand in hand. Before we’ve even put metal to use, the mining industry employs magnets to locate valuable metal in the ore they mine. Later in the process, miners use magnets not for the metal they want but for the metal they don’t. Bits of impurities and shrapnel called “tramp metal” left over from explosions and excavations can wind up where they don’t belong and damage other pieces of machinery. A pass under a magnet will catch these bits of tramp metal.
Mining for metal is necessary at one point, but our goal is to reduce our mining by recycling the metals we already have. To that end, recyclers use magnets as they sort and resell metal for reuse. Recyclers use basic magnets to distinguish between those metals that contain naturally magnetic iron and other metals that are not immediately attracted to a magnet—the latter is more valuable for resale. With the help of electric currents, magnetic separators can even separate copper from plastic to aid in recycling used copper wiring.
Whether for passenger rail or freight, the railroad industry relies on magnets to help lay down the trackage that traverses our continent. Magnets do the heavy lifting of putting rails into place and, in turn, can lift them out of decommissioned railways. As railroads rebuild their rails, magnets are instrumental in recovering other track materials, such as spikes, tie plates, and anchors.
With so many fragile and moving parts, metal impurities can infiltrate the manufacturing process in the pharmaceutical industry. Even the medicine we take relies on an industrial application of magnets. To prevent this harmful contamination and the loss of the public’s trust, quality control operations in manufacturing facilities use powerful magnets to find these metallic impurities and remove them from the line, keeping users safe.