Recycling of metal and aluminium knows no limits because it can be rcmcltcd as scrap indefinitely. Mclals, however have to be separated from non-metallic impurities, and different metals have to be sorted in pure fractions to be used as secondary raw materials substituting primary resources. Especially when it comes to aluminium a lot of energy can be saved when remclting aluminium scrap. By using secondary raw materials in the production of aluminium, the energy-intensive electrolyses process is eliminated, thereby reduccontains olher non-ferrous metals such as copper, zinc, brass, stainless steel.
Zorba - a cheap resource
Nowadays, most of Zovba produced in Europe and USA is exported to China as separate mixed aluminium (defined by ISRI as Twitch) and mixed heavy metal fraction. However, more and more Zorba is expected to stay within Western countries as a result of rising labour costs in China and surplus of primary based sorting, however Zorba and Twitch can be further sorted.
An XRF-machine is capable of sorting aluminium alloys based on their zinc and/or copper content. Taking Zorba as example, it is possible to sort in three different aluminium categories: one low zinc low copper fraction compatible with semi prime foundry alloys such as 356.1, one high copper high zinc fraction compatible with regular die casting alloys such as Din 226 (or A380 in the USA) and one fraction with medium contents of zinc and copper compatible with piston alloys. Red-wave calls this process 3-way-sorting.