Urban mining for aluminium

Delivering low carbon aluminium façade packages is something specifiers, fabricators and installers are having to understand, and fast. Here, Graham Hurrell, head of specification sales for Wicona, explains how post-consumer aluminium scrap from urban mining is being turned into high-quality façade systems.

One of the chief issues for the construction industry comes at the end of a building’s life, in which the scrap from a demolished building may be sent for incineration, or to landfill or an uncontrolled or undocumented recycling or downcycling process.

This is certainly not conducive to a circular economy approach, and it is a major loss of valuable materials. A solution to this problem is urban mining.

Urban mining is the process of recovering materials that are reusable from obsolete infrastructure. This process is incredibly useful for metals due to the high levels of energy needed to mine and process raw materials, along with the fact there is a finite amount available.

For context, recycling aluminium to create a new product requires only 5% of the energy needed for manufacturing the product from bauxite ore. Furthermore, aluminium can be recycled indefinitely without its structural capabilities and other basic properties diminishing.

In order to meet commitments to net zero, building owners and developers are placing an increasing focus on building sustainably. As a result, the building products specified are increasingly required to be low carbon wherever possible. Hydro Circal fulfils this idea in an incredibly unique way – through the use of recycled and scrap materials.

Hydro Circal 75R is our own brand of recycled aluminium made with a minimum of 75% recycled, post-consumer aluminium scrap. By using recycled aluminium to create the product, we substantially reduce the energy use throughout the production phase, while still providing the same high-quality aluminium.

The Hydro plant in Dormagen, Germany has developed the technology to sort and separate aluminium from other metals, efficiently directing each one for the correct recycling process. This system allows aluminium with the right alloy to be sent to Hydro’s melting plants.

The evolution of post-consumer scrap processing, as seen with the Hydro Circal 75R, ensures that the end product, for example Wicona facades, is indistinguishable from products sourced from primary aluminium or pre-consumer material. And can be powder coated or anodised as usual.

Using durable and recyclable materials with a low carbon footprint will contribute to a large CO2 reduction on building projects. Hydro Circal has a carbon footprint among the lowest in the world: 2.3 kg CO2 per kilo of aluminium, 73% less than the European average, certified by an independent third party (DNV-GL) and provided with an Environmental Product Declaration (EPD)1.

It is crucial that the construction industry is building with a vision of the future, and with the consideration that resources are finite. Urban development is completely implausible without the sustainable reuse of materials.

We are demonstrating our focus on sustainability by using Hydro Circal for our system solutions, one of the most sustainable aluminium alloys in our sector. In fact, the latest Wicona systems contain at least 75% recycled and 95% recyclable content, minimising the carbon footprint of our new products even further.

Hydro Circal 75R has been used in the construction of the 106m high Senckenberg Turm, in Frankfurt, Germany, creating a dazzling anodised façade.