Urban mining: Hidden riches in our cities

Cities hold tons of materials that can be reused — and doing so can address over-exploitation of scarce natural resources. From buildings to electronic waste, we are surrounded by value. So how does urban mining work?

With demand of natural resources increasing and supply decreasing, the use of recycled materials is gaining importance. 

Nature and Environment | 02.06.2018

Mineral resources like concrete, bricks or ceramics can be found in large quantities in many buildings across countries like Germany. Metals such as steel, copper, and aluminum, and materials like plastic, gypsum, asphalt and wood are also abundant. Household waste is also a major source of valuable materials.

Urban mining has many advantages over primary mining: the materials are already in the city where they are likely to be needed again, so there is no need for long transport routes. And the environmental impact, particularly in land use, is clearly lower than mining for natural resources.

"As the use of fossil fuels becomes more complex and expensive, recycling secondary raw materials will become more competitive," predicts Jasmin Mangold of Bonn Orange, a German waste management company.

Nature and Environment | 02.03.2018
 Recycling Urban Mining

Even ceramic waste from dishes, toilet bowls or sinks can be recycled

Just about everything can be reused

Each German produces almost 500 kilograms (1,102 pounds) of waste per year. Workers at the Bonn Orange recycling facility in Bonn, Germany, struggle to sort out all kinds of citizen waste: computers, televisions, refrigerators, washing machines, batteries, fluorescent lamps, rubble, CDs, oils and paint.

The paint is dried up to make chalk, the rancid oils are processed into cosmetics, and old devices dismantled to recycle materials such as paper, plastics, metals or glass, workers explained to DW. 

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Concrete recycling

Buildings, furniture, electrical appliances and old radiators are just as much part of industrial society's "anthropogenic deposits" as disused railways, industrial wastelands, underground cables or that old cell phone forgotten in the depths of your drawer.

These so-called secondary raw materials can be reused for commercial and industrial production, thus limiting imports from abroad, protecting natural resources and the environment.

For recycling experts, a simple car represents a large manmade stock of raw materials; even a rusty old car has value. The Internet is full of retailers looking for gears, doors and other replacement parts. The iron, plastic, glass and metal can all be sold to make new products. Tires can be processed into road surfaces or insulating material.

Recycling Urban Mining

Recycling can give old tires a second life

A fortune in waste

"We are surrounded by a manmade stockhouse of more than 50 billion tons of materials," Maria Krautzberger, president of the German Environment Agency (UBA), said in a statement.

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If all industrial infrastructure, buildings, and waste products were considered as valuable materials, this would represent for each German citizen: 317 tons of mineral materials, 14 tons of metal, more than 4.3 tons of wood and 3 tons of plastics.

And this anthropogenic deposit is growing each year by another 10 tons per inhabitant of Germany, according to UBA data.

The value of metals alone in Germany's anthropogenic deposit is estimated at €650 billion ($800 billion). In an ongoing shift, those materials are being viewed not as a burden, rather as a fortune.

Recycling Urban Mining

Don't forget to recycle your scrap. Metal waste can be completely re-processed

Urban mining for a circular economy

"Recycling is a key industry for the way to a resource-efficient circular economy," Felix Müller, an industrial chemist with UBA, told DW.

The production of a one-ton car requires 15 tons of primary raw materials, including mineral ores and fossil fuels.

"Secondary raw materials represent high savings, because they do not have to be refined — only melted down," Müller explained.

By means of comparison, "To produce one ton of electrical steel from scrap, only 0.8 tons of primary raw materials are required and only one-third of the energy input," Müller pointed out.

At least in Germany, that seems to be acknowledged as the way forward: 30 percent of semi-finished copper and copper casting production in Germany, for instance, is already produced from domestic copper scrap, according to the UBA.

Recycling also enjoys high popularity among citizens, and is often the public preference to plundering natural resources abroad or shipping large quantities of garbage to Africa or China.

Backing this up more broadly, circular economy has been identified as a major target across the European Union.

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Mountains of old electronics

Guiyu in southern China was long considered the world's biggest electronics recycling site. And it was a highly polluting one at that. More than 5000 small family-run businesses recycled everything from screens to motherboards.

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A million little pieces

Poor workers did much of the recycling — dismantling, sorting and processing the components by hand. This work often took place in homes or by the side of the road, and frequently with little or no protective gear.

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Burning plastic and worse

But the process was very dirty. People burned parts or used toxic chemicals to separate precious metals and other materials from the components. The air was filled with toxins and the ground water became so polluted that it wasn't suitable for drinking.

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A modern facility

In 2013, the provincial government stepped in. It built a large industrial park on the city's outskirts. If recyclers wanted to stay in business, they had to move to the facility, which was equipped with modern air and water filtration systems to protect the environment.

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Smaller margins, cleaner air

By 2015, the facility was open for business. Having to rent space there cut into the profit margins of smaller companies. Some went bust, but the upside was that air quality improved dramatically. The streets are cleaner too, say residents.

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No more foreign trash

This year, China decided it no longer wanted to be the world's dumping ground and banned imports of 24 kinds of waste. As a result, there are no more discarded and broken electronics arriving in Guiyu from Europe or the United States. Well, not officially.

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Illegal imports

For years, China neglected local waste because so much was flowing in from abroad. It arrived better sorted than domestic trash and was more economical to process. Even now, some recyclers are turning to more lucrative illegally imported electronic waste.

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Time to start separating the garbage?

But now Beijing plans to invest billions in household waste treatment over the next few years to deal with its domestic trash problem. According to local media reports, Chinese authorities are trying to encourage people to sort their trash properly at home.

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