Aluminium-Recycling | Climate protection requires holistic solutions

Article by Thomas Reuther

Climate protection is a task for society as a whole. Industry must also play its part in meeting the global climate protection targets of the Paris Agreement and the 17 Sustainable Development Goals of the United Nations. An important building block is the expansion of the circular economy to become a mainstay of industrial value creation while at the same time conserving resources. Here the aluminum industry can point to a high technical standard and a high recycling rate.

At the end of its useful life, the light metal becomes a valuable raw material. Functioning cycles have established its collection, sorting, processing and reuse. With great effort, aluminum residues from municipal waste are brought back into the cycle.

Recycled aluminum has a firm place in the supply of raw materials to industry. The ecological benefits are well known: Recycling aluminum makes the energy stored in the material usable again in each cycle. Remelting scrap requires only five percent of the energy needed to produce primary metal, and it saves 85 percent CO2. The reprocessing can be repeated as often as required without any loss of quality. Each cycle improves the energy balance of the material and reduces its CO2 footprint.

The greatest possible use of scrap in the provision of aluminum materials is ecologically imperative, economically sensible and technically feasible. At TRIMET Aluminium SE, recycling management is an integral part of aluminum production. The business areas Recycling and Primary Products have always been closely interlinked.

Together with our customers, we have established closed material loops with which secondary raw materials are returned to production, where they distinguish high-quality products with an improved climate balance. In this so-called closed-loop recycling, TRIMET turns over more than 270,000 tons of recycled aluminum annually. Recycled aluminum accounts for around 40 percent of the production volume.

The integration of recycled material is also a focal point in the development of new materials. Today, aluminum alloys are not only required to have properties such as strength, corrosion resistance or conductivity. The carbon footprint is equally relevant. TRIMET's research laboratories are working to further increase the recycled content in alloys without compromising the properties of the material. Some TRIMET alloys consist of 95 percent recyclate.

Taking a holistic view of materials supply

In order to promote the circular economy in the service of climate protection and resource conservation, material flow-specific minimum input quotas are being brought into play by various parties. In the case of aluminum, however, measures of this kind are the wrong approach for several reasons. First, recycled aluminum is a valuable secondary raw material in a functioning market that does not require regulatory incentives or constraints. For another, limited quantities of scrap face an increasing demand for aluminum, which means that in the future, despite increasing recycling volumes, the use rate of aluminum scrap in total consumption may actually decline.

Aluminum is a relatively young material.

New applications are still opening up for the light metal in mechanical and plant engineering, the electrical industry, construction, packaging and the energy sector. The requirements of climate protection and the energy transition are promoting this development. This applies in particular to the largest field of application, the transportation sector. The use of aluminum in vehicle construction has tripled since 1960 and will continue to rise. Means of transport for road, rail and air traffic are dependent on lightweight construction.

"Design for recycling" plays a prominent role in aluminum recycling. For example, plastic blisters can be dispensed with in the packaging of pharmaceuticals and only aluminum foil can be used.

More than three million tons of aluminum are processed in Germany every year. Only 1.2 million tons come from domestic production. Almost two-thirds of the required volume is covered by imports of primary aluminum, on which we will continue to depend in the coming years. Recycled materials alone cannot meet this demand. In addition, aluminum is mostly used in long-life products. This means that the raw materials can only re-enter the cycle after a long period of time. The material used in vehicles and window profiles only returns to the market after years or even decades. 

Recycled materials alone will not be able to ensure the demand for aluminum in the foreseeable future. The aluminum circular economy should therefore be further developed as part of a holistic view of raw material supply. Unused potential exists. The biggest lever is in optimizing product design.

The design of products has to take into account many market requirements. Up to now, the focus has been on features such as product safety, functionality and marketability. In the future, it will be just as important to manufacture products in such a way that, at the end of their useful life, they are available again in as many cycles as possible without any loss of quality in conjunction with the available technologies. Design for recycling" can ensure that products allow technically efficient and economically viable sorting and processing so that they can be used again in production.

This will make a not inconsiderable contribution to climate protection. Holistically understood sustainability, however, must start even before that. For the foreseeable future, we will not be able to do without primary aluminum. TRIMET is therefore pursuing the goal of producing electrolytic aluminum in a CO2-neutral manner in its aluminum smelters by 2045.

This article also appeared in Aluminium Journal 05/2022