More Questions and Answers
Q: How do I know which magnet is best for my application?
Typically, you'll choose between ceramic or rare earth permanent magnetic circuits when processing dry bulk materials.
A ceramic magnet consists of strontium and iron oxide. This magnet type provides the least magnetic energy and is the least expensive of the permanent magnets. In general, you'll choose this magnet when your main goal is capital protection. This means that large tramp iron, including nuts, bolts, knives, and screwdrivers are removed and prevented from entering downstream equipment.
Conversely, a rare earth magnet has the strongest magnetic energy and is the most expensive compared to the other permanent magnets and is made from lanthides, which are elements 57 to 71 on the periodic table. Neodymium is the most commonly used rare earth element for magnets. This magnet is optimal for consumer protection because of its strength and holding capabilities, allowing it to capture small and weakly magnetic fines that could end up in your final product. In all processing facilities, there exists the potential for metal shavings, filings, iron powder, and items like wire mesh to enter the material stream and pose a danger to consumers and your company's reputation. A rare earth magnet will capture this tramp iron throughout the facility if placed properly in the processing stream.
Specialty magnets can be made from materials like alnico and samarium-cobalt, which are used to remove contaminants in high-temperature applications, for electromagnetic circuits, and for removing larger tramp iron on conveyor belts, but these are less commonly used in the dry bulk materials industry.
Industrial Magnetics Inc., Boyne City, Mich., designs and manufactures permanent magnetic and electromagnetic devices for magnetic separation, material handling, work-holding, and automated or robotic applications.