Oct 17, 2022
Aluminum: the environmental impact
Is aluminum a friend or a foe of the environment?
Aluminum’s qualities make it one of the most sought-after minerals for manufacturing materials. Its lightness, maneuverability, durability, and thermal resistance make aluminum an essential material in many economic and productive sectors.
Many components in the automotive industry, construction, or home appliance manufacturing are made from aluminum. If we go into a kitchen, we will find many everyday products made from aluminum, such as soda cans and aluminum foil, among others.
But there’s a dark side to the versatility and convenience offered by aluminum, one with severe environmental and human impacts. It is generated along the entire process of obtaining aluminum. Aluminum is the third-most-used mineral after iron and steel. Given that, it’s time to rethink how we can meet the challenges aluminum currently helps us solve.
How is aluminum obtained?
Aluminum is not a pure mineral found in the environment. However, it is present in other minerals or rock compounds, such as some clays, kaolins, or feldspars. Most aluminum (20-30% by mass) is extracted from bauxite – a rock composed of hydrated aluminum oxides. The bauxite extraction process is open pit mining. Various methods are applied to bauxite to obtain liquefied aluminum, used to obtain aluminum as a thin material. During these processes, bauxite dissolves with sodium hydroxide (Bayer process), and the elements are finally separated by electrolysis.
Currently, bauxite mines are located mainly in tropical and subtropical regions. Most of the world’s bauxite is mined in Guinea, Brazil, Jamaica, and Australia. It is estimated that approximately four tonnes of bauxite must be processed to obtain one tonne of aluminum. The process generates many toxic residues, including caustic mud, which seriously contaminates the environment.
What about the environmental impact of aluminum?
Bauxite mines have a significant environmental impact on their environment. The mines are open, and the environmental effects are more severe than with underground mining since the damage is largely irreversible. Bauxite extraction erodes the soil and removes all the flora, essentially eliminating any fauna of this environment at the same time.
The pollution generated by the aluminum industry is problematic. Indeed, it produces millions of tonnes of greenhouse gases per year, such as carbon dioxide, gases in acid rain, sulfur oxide and nitrogen oxide. In addition, converting bauxite into aluminum requires large amounts of energy and water.
Moreover, this activity is the indirect cause of deforestation in the area near the mine. It can be explained because mining companies build access roads leading to the mine through the surrounding countryside. This improves accessibility for other industries, such as saw milling, coal production, and other activities that contribute to deforestation of forests or jungle areas.
Furthermore, mining bauxite is a source of other conflict in the territory. Mining activities often involve the displacement of villages and the loss of traditional ways of life, such as:
– loss of local plants with traditional medicinal uses
– the inability to produce crops
– severe restrictions on hunting or maintaining livestock.
Alternatives to aluminum
Aluminum, being inorganic, can only be oxidized or combined with other substances. Therefore, in addition to generating pollution, aluminum waste in the environment is not biodegradable and can last up to 200 years. The most viable and feasible way to deal with waste is aluminum recycling.
Aluminum containers are straightforward to recycle, the metal does not lose quality, and the process can be repeated a number of times. Aluminum recycling saves about 95% of the energy needed to produce pure aluminum from bauxite. In other words, the same amount of energy is required to create an aluminum can from bauxite, as to produce up to 30 cans from recycled aluminum. Despite this, global recycling of aluminum packaging is not even half of what is consumed.
Moreover, some companies use the term “100% recycled” when talking about aluminum packaging. This can be missleading since a significant amount of this recycled content comes from production scrap which did not have a first life. If the metal does not lose quality it’s therefore because it receives a certain portion of new aluminum to regenerate the product. Not really what we have in mind when we want to avoid extract new resources.
You might be interested in this article: “End of rare metals: time to choose”, read it here.