The urban mine: tapping resources in the world’s waste

Chris Lo 28 March 2018 (Last Updated June 14th, 2019 10:43)

European consortium ProSUM has launched Europe’s first comprehensive database of the raw resources that could be recycled from the continent’s electronic and vehicular waste. How does the database work, and how might it inform post-consumer e-waste ‘mining’ in the future?

The urban mine: tapping resources in the world’s waste
Scrapped vehicles are likely to become an important source of secondary raw materials to feed back into the supply chain. Credit: hillman54

Reserves of minerals and metals that can be economically extracted by the mining industry won’t last forever. While technical advances in the sector have facilitated the mining of lower-grade deposits, as the decades have passed the prospect of ‘running out’ of certain metals – where the only reserves left are uneconomical and technically difficult to extract – is becoming more real.

Concerns have been raised for the future supply of critical metals, from rare earth elements to indium, cobalt, gold, silver, rhodium and zinc, some of which have been flagged, at current production rates, as becoming unavailable to mine in the next 15 to 20 years, unless major new discoveries emerge.

Waste and the circular economy

How does a global society, one that is as dependent as ever on key industrial metals to feed into the production of basic products and high-tech gadgets, begin to square this circle? For advocates of the ‘circular economy’ – a broad concept describing a society that emphasises resource conservation and recycling as opposed to the linear economy’s ‘take, make, dispose’ model that has dominated global industrialisation – one answer lies at the opposite end of the supply chain to the exploration and production activities that occupy the mining sector.

Take the average car, for instance, which contains more than a tonne of iron and steel, 240lbs of aluminium, 42lbs of copper, 41lbs of silicon, 22lbs of zinc and a host of other mineral commodities in small amounts, including gold, platinum and titanium. With vehicles, along with discarded batteries and electrical and electronic equipment (EEE), often going to landfill, the chance to re-process these products and make use of their useful raw materials is too often missed.

More extensive recycling of waste metal could bring incredible sustainability benefits, from saving energy and water to avoiding excessive environmental impacts from primary production. Scarce supplies have left most countries relying on international suppliers for many mining commodities, so recycling could help countries reduce their dependence on imports. There is a financial opportunity too; according to the UN’s Global E-waste Monitor 2017, published in December, the 44.7 million tonnes of e-waste (electronic waste) produced worldwide in 2016 contained metals and other materials worth €55bn.

“Circular economy models need to be adopted to encourage closing the loop of materials through better design of components, recycling, reusing, etc., while mitigating environmental pollution,” the report noted. “Therefore, the circular economy concept offers huge economic and employment opportunities for e-waste management; the presented €55bn of secondary materials is an underestimate of those economic opportunities.”

ProSUM’s Urban Mine Platform

In a perfect world, society’s consumption of mining products would be a closed loop, with all metals recycled into new products and the mining industry stepping in to extract new commodities to make up for metal dissipation and demand growth. Ours is far from a perfect world, however, and such a comprehensive recycling system – if it is even technically feasible – is a long way off.

One of the many deficits that needs to be made up is information – estimates on waste metals and recycling rates vary greatly, and tend to be fragmented between many organisations.

In Europe, the Prospecting Secondary raw materials from the Urban Mine and Mining Waste (ProSUM) consortium, a partnership of government organisations, companies and research groups, has stepped in to address this data deficit. Under the aegis of EU’s Horizon 2020 research and innovation programme, ProSUM (the abbreviation translates to ‘I am useful’ in Latin) recently launched the Urban Mine Platform, a digital database presenting the flows of precious and base metals and critical raw materials in products in use and throughout their lifecycle.

Reliable data on sources of secondary materials

Tracking the stocks of vehicles, batteries and EEE in EU member states, as well as Norway and Switzerland, the Urban Mine Platform is intended to inform policymakers and academics with reliable raw data, not to mention metal recyclers and the mining industry, the latter of which could benefit from greater certainty about the quantities and types of materials needed in the European market.

“Until now, data on such critical raw materials have been produced by a variety of institutions, including government agencies, universities, NGOs and industry, with the information scattered across various databases in different formats and difficult to compare or aggregate and often representing an outdated snapshot for a certain year only,” said ProSUM scientific co-ordinator Jaco Huisman. “The ProSUM effort helps remedy that problem, and enables the identification of so-called ‘hotspots’ – the largest stocks of specific materials.”

Raw data from the Urban Mine Platform reveals that each year across Europe, around 10.5 million tonnes (Mt) of waste EEE, 2Mt of batteries and 7Mt to 8Mt of vehicles leave the market as waste. Breaking down the base components of these waste flows uncovers a rich source of secondary critical raw materials.

For example, recycling all of Europe’s waste batteries could yield around 720t of lithium and 2,700t of cobalt, just as demand rises for these commodities, driven by the growth of battery and electric vehicle (EV) manufacturing. And as EVs begin to leave the market at a higher rate in the coming years, waste vehicles are likely to become a more important source of secondary raw materials to feed back into the supply chain. A year’s worth of European e-waste, meanwhile, contains around 1,000t of neodymium, an element used in electronics, EV motors and various types of wind turbines.

One piece of the puzzle

Clearly, providing this data is only one piece of the recycling puzzle, which will continue to throw up issues for many decades to come. There has been an uptick in both supportive policymaking and technology development in the field in recent years, from high-tech sensor-based technologies to sort and recover nonferrous metals to simpler manual dismantling activities in developing countries. Metals such as steel, aluminium and copper are already recycled extensively in Europe and elsewhere.

Nevertheless, the certainty provided by the Urban Mine Platform could go a long way to encouraging the development of the metal recycling sector in Europe.

“Better knowledge of amounts and content of critical raw material is fundamental for both research in the field of recycling and as a background material to convince a board in a recycling company to fund investment in recycling capacity,” said Christer Forsgren, adjunct professor of industrial material recycling at Chalmers Technical University in Sweden, one of the ProSUM partners.

“Legislators need similar information to develop for society efficient Extended Producer Liability Systems. The database developed by the ProSUM project is a very good start and one step closer to a more circular economy.”

What does this changing dynamic mean for mining companies? Attitudes will likely vary by company, but as Cambridge University senior associate Wayne Visser noted in a 2014 editorial for The Guardian, a successful shift towards more efficient post-consumer use of important resources will require change from the mining industry, as well as wider society.

“Extractives companies need to recast themselves as resource stewardship companies – experts at circular production and post-consumer ‘mining’,” Visser wrote. “And customers and governments need to give up their compulsive throw-away habits and embrace the take-back economy.”