What is urban mining – and why do we need to do more of it?

The number of smartphones in use hit 6.6 billion in 2022. That means the vast majority of the world now owns one. And inside each of those phones is a pinch of multiple different metals and minerals, some of which are rarer and harder and more damaging to extract than others.

But each of these phones also has a limited life – how many people have an old device sitting unused in a drawer somewhere? One piece of research estimates that there are around 7 million unused phones in Switzerland alone, with $10 million worth of embedded gold in them.

It is exactly issues like these that make it so important we get an urban mining system up and running in a sustainable and cost-effective way.

Urban mining is the idea of extracting valuable materials from waste, much of which would otherwise go to landfill or incineration. This can include common metals and plastics as well as rarer but valuable elements.

Urban mining allows us to salvage materials of which there is a finite supply, and limits the environmental impact of their disposal. Crucially, it also avoids extraction of additional materials, which damages ecosystems and can cause pollution, among other things.

It forms a key part of the circular economy, which promotes a more sustainable use of resources by keeping them in use for as long as possible.

The World Economic Forum’s Platform for Shaping the Future of Consumption is seeking to promote responsible consumption models, which are equitable, enable societal well-being and protect the planet. A key part of the initiative is focused on innovative reuse models.

Electronic waste (e-waste) like phones is a prime candidate for urban mining, where products cannot otherwise be repaired.

There are a growing number of companies which offer to buy back and resell unwanted devices, as well as a wave of repair cafes emerging. But these devices are still not routinely considered an economically viable secondary source of materials like gold, silver, copper, lithium, or cobalt.

Once you factor in the environmental costs of extracting these materials, however, the scales tip in favour of urban mining, research suggests. Many of the participants in the Swiss phone study mentioned above said they would be willing to sell their old phone for less than $5. The market value of the metals within them is under $2, but when you factor in the external costs of extraction the cost of the materials is around $18.

Another strong use case is for waste materials from demolition or construction. Around 850 million tons of construction and demolition waste were created by Europe alone in 2020 – more than a third of all waste generated in the region.

Steel, copper and aluminium are commonly found in demolition waste. And there are also ways which cement – a notoriously polluting material in its production – can be reused and recycled. Some processes even manage to capture and store carbon in the new product. Aggregates and bitumen from worn-out roads can also be recycled into new ones.