Why is magnets recycling so important?
Magnets are found in a wide variety of devices and equipment, but only a small fraction of them are recycled. While awareness of recycling plastic, metal, glass, or paper is already relatively high, when it comes to magnets, they end up in the trash primarily due to ignorance, and secondly because there is really nowhere to dispose of them. It is estimated that only one percent of magnets are recycled, which is a very low rate by current standards. Therefore, there are increasing calls to seriously address this issue, especially since there are already technological capabilities to do so, which were a significant obstacle some time ago. Proper technologies allow for the recovery of metals used in production through complex processes, and another direction is to use discarded magnets in other applications. Recycling has an environmental dimension - everything that ends up in a landfill is irretrievably lost, unless it ends up in the forest or at the bottom of a lake. But an additional problem recently is the regulations introduced by the Chinese government. They aim to significantly reduce the supply of rare earth elements, making their recovery increasingly necessary.
Modern methods of magnets recycling
Most recycling methods start with demagnetizing the waste, usually by heating it to the appropriate temperature. Then, the metal recovery process is carried out, with a primary emphasis on the highly desirable neodymium. One method utilizes the properties of liquid magnesium. Crushed magnets are poured into a container to which magnesium is added. The mixture is then heated using radio waves, causing the magnesium to become liquid. Through the phenomenon of diffusion, valuable elements pass into the solution, which is then cooled and evaporated. As a result of this process, high-quality raw material is obtained, which does not differ in properties from the original. Another idea for neodymium recovery is to use hydrogen for this purpose. Intensive research in this direction is funded by the European Union, and the first successes are already visible. Hydrogen is used to produce hydrogenated powder, from which neodymium would then be obtained. Scientists have estimated that significantly less energy is consumed during the entire process compared to mining rare earth metals, making this method a valuable alternative to purchases in China in the near future.
Poor quality magnets
On many websites, you can find neodymium magnets with a density lower than N35 - these are from so-called recycling. Every month, about 40 tons of magnets from old HDD hard drives flow from Poland to China. After processing, they return in semi-finished products and are sold for other purposes.
Magnets in automotive
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sobota 2020-05-02T18:00:00