subject: The Recycled Magnesium Alloy Appeal [print this page] The Recycled Magnesium Alloy Appeal The Recycled Magnesium Alloy Appeal
One of magnesium's admirable attributes is its recycle-ability. The metal is certainly one of the most abundant. However, the ability to recycle if without compromising the integrity of the metal is an attribute that few metals have. The most common ones that share such a trait are surprisingly the most common alloy partners of magnesium including aluminum. In fact, the recycle-ability factor involves much more than the metal's structural integrity after it comes out of the recycling process.
Recycling Sources
Magnesium alloy comes from two sources: scrap and waste materials. Scrap magnesium comes from products such as computers, cameras and wheels that are made of magnesium and have been discarded. The materials are stripped of excess materials and submitted to high heat to remove other impurities. Magnesium has a much higher melting point than other metals, so the plastic and other materials that are usually added to the magnesium to create the original products are melted away without losing much of the magnesium. The result is a very pure form of the metal.
Waste magnesium comes from the casting and molding processes. According to Fujitsu, about 50 to 70% of the metal is lost in the form of waste during the processes. The company states that most of the melted metal is lost in the runners and sprue (where the melted metal is placed into the mold). Waste magnesium alloy is as close to the virgin metal as you can get. It is virtually free of impurities and ready to be reused. The majority of recycled magnesium comes from this source.
Purity
Magnesium alloy purity is a characteristic that has made the metal more attractive as a resource. Alloy that is free of other metals and nonmetal compounds are stronger and closer to their virgin metal state. Interestingly, purity issues are what caused magnesium's popularity as a metal to die off in the 1970's and 1980's, only to come back in the millennium when process like thixomolding have made it easier to keep impurities out of the metal. Heating the metal to high temperatures also helps. Cleaning scrap magnesium of all excess materials is also key. The paint must be stripped as well.
No Emissions
Companies are drawn to materials that are better on the environment. Companies looking to produce greener cars, electronics and equipment always consider recycled magnesium. In addition to being reused or reclaimed from the molding process, magnesium is easily recycled without creating dust and gas emissions like other metals. However, the emissions are dependent on the recycling center's ability to clean the plastics and paint from the scrap magnesium before melting. Done correctly, the process should yield little to no emissions.
Even recycled magnesium seems to be a wonder metal for the industries of America. It is abundant without the re-usability factor, but magnesium's appeal after the recycling process gives the metal even more appeal. Companies are actively pushing the limits of how the metal can be used to replace the nonrenewable materials currently in use today.
