It is hard to believe that recycling aluminum, which is both environmentally friendly and cost effective, could have any disadvantages. As Portland State University points out, it takes 95 percent less energy to recycle an aluminum can than it does to create a new one from aluminum ore. Despite this statistic, the recycling process for aluminum is not perfect, and several problems still abound.
According to the recycling resource website Benefits of Recycling, after the collection stage, the aluminum recycling process requires that workers crush and shred the aluminum materials, mix them with virgin, mined aluminum ore and then heat them in large melting furnaces. From a pollution standpoint, there are two large problems with this series of events. By using virgin aluminum ore, companies still rely on an energy-intensive, non-"green" strategy, as it takes a lot of gasoline and electricity to power mining equipment and transport ore across the country. Additionally, as mechanical engineer and environmentalist James Dulley notes, melting down aluminum, even if it is recycled, still produces toxic emissions.
While the aluminum industry may be able to solve the pollution problems associated with its recycling process, as of 2010, there are no indications that this will happen any time soon. As Dulley mentions, the aluminum industry does not have the economic motivation to invest large sums in to researching and developing new pollution-reducing machines.
While aluminum cans consist exclusively of aluminum, other "aluminum" products can consist of aluminum alloys. As Educational Electronics USA notes, three of the most common aluminum-based alloys that manufacturers use are duraluminium, magnalium and alnico. Duraluminium contains copper and aluminum; magnalium contains magnesium; and alnico contains nickel, cobalt and iron. You can find these alloys in a variety of different items, such as home appliances and aircraft and automobile engines. Although you can recycle aluminum alloys, Dulley notes that they have a low demand amongst manufacturers, so processing plants have a low interest in recycling them.
Even if a processing plant is careful to only recycle products that consist entirely of aluminum, there is still the potential for contamination. According to Dulley, some of the most common culprits are iron, tin and lead. The problem with having even slight amounts of impurities in the aluminum is that these impurities can vary the aluminum's properties. In some instances, they can weaken the aluminum. This potential for contamination also makes it hard for plants to develop long-term contracts with clients, such as municipalities, that may be wary of the low-value material.