Recycling critical materials: a second chance for the things that make the world go round

We want a world without emissions, but to achieve this, we depend on minerals and other elements to manufacture solar panels, wind turbines, and electric vehicles. And this is where the paradox of the energy transition arises: while we seek to reduce dependence on fossil fuels to combat climate change, the need to exploit new resources in the subsoil is increasing. The challenge is that most of these materials are found in geographically concentrated areas, and extracting them can have environmental and social impacts, such as emissions, deforestation, and water pollution. Added to this is growing geopolitical tension over control of these resources. A paradigmatic example is Greenland, which is in the US's focus, in part, because melting ice will expose large quantities of strategic materials. In this context, is Europe prepared to guarantee its supply? Can they be obtained more sustainably? Science seeks answers.

First of all, the term must be understood critical materials Such as mineral resources and elements that are of great economic importance because they are essential for the functioning of sectors such as renewable energy, electric mobility, digital, aerospace, and defense, but whose supply is also at high risk of disruption. In the case of Europe, the Commission promoted a list of critical materials in 2011, which is updated every three years: "New materials may be added or removed at each revision."explains Abigail Jiménez-Franco, PhD in mineral deposits and research technician at GEO3BCN-CSIC. The expert also clarifies that not all critical materials must necessarily be linked to mining: rubber is one example.

Focusing on the energy transition, some examples of critical materials include lithium, which is used to make electric vehicle batteries and energy storage systems; perovskite or silicon, used in the manufacture of solar panels; and rare earths, which comprise a total of 17 elements, including neodymium, praseodymium, and dysprosis, key elements for wind turbine magnets.

More sovereignty in the EU and a more circular economy

The reconfiguration of the new world order, with goals like Trump's return to the White House, has pushed the European Commission to increasingly pursue greater autonomy in obtaining these precious materials. It has already set a goal of extracting at least 10% of annual consumption within Europe by 2030. To this end, it has promoted programs to search for new materials, "some of which are very difficult to locate because they are found in very small quantities and mixed with other elements, as is the case with rare earths," adds Jiménez-Franco.

However, this commitment to increasing extraction has also raised concerns among various communities and social movements that warn of the environmental and social impact of mining. For example, a report promoted by heEnvironmental Justice Atlas (EJAtlas) has already documented more than 25 conflicts linked to the entire rare earth supply chain worldwide. Some of the cases are located in countries such as Norway, Spain, and Sweden and share concerns such as a lack of transparency and decision-making processes that are not very inclusive of the population, "although each case has its own unique characteristics," highlights Mariana Walter, researcher (IBEI) and member of the EJAtlas coordination group.

However, beyond extraction, the EU also wants to boost the recycling of critical materials and has set a target of at least 25% of annual consumption coming from domestically recycled minerals.. Its use means savings in raw materials and CO₂ emissions and It is more advanced for those metallic minerals produced in large quantities, such as aluminum, iron, and copper, which is not the case for other critical materials. These materials are found, for example, in the old cell phones we accumulate in drawers, which contain copper, aluminum, silicon, or lithium. Electric scooters and cars also contain real gold mines in their batteries, containing essential elements such as graphite, nickel, cobalt, and manganese.

"Right now, recycling is done primarily through two processes: hydrometallurgy, which involves dissolving the entire product in an acid to later recover the materials, and pyrometallurgy, which involves calcining everything and then separating the metals from the mixture," says M. Rosa Palacín, researcher (ICMAB-CSIC).

In Spain, there are already initiatives committed to giving a second life to the metals found in electronic waste. A prominent example is the RC-Metals laboratory, a unique pilot plant in Europe led by the CSIC, which works to recover critical materials using various technologies, such as molten bath smelting. "The goal is to find efficient methods to reuse all these resources," explains Fèlix A. López, a chemist and CSIC researcher participating in the project. Along the same lines is CirCular, an Atlantic Copper initiative in Huelva, which also aims to recover metals from end-of-life electrical and electronic equipment.

In addition to recycling, science seeks to reuse critical materials found in old mine waste. This is the case with Ti-rres project, which investigates the revaluation of materials in a mine closed in the 1990s in Golpejas (Salamanca). The objective is twofold: to recover metals such as tar, tantalum, niobium, and rare earths, and to evaluate the feasibility of restoring the land after extraction. "The waste accumulated in ponds and waste dumps, unused due to the technological limitations of the time, but today it represents an opportunity," explains Teresa Llorens, senior scientist at the Geological and Mining Institute of Spain (IGME-CSIC) and principal investigator of the project. Other mining waste recovery initiatives in Spain include the Penouta Lake mine in Galicia, the Los Santos tungsten mine in Salamanca, and the RECCOPS, aimed at recovering critical materials such as bismuth and antimony from the waste generated during primary copper production.

The challenges of recycling

Although European regulations favor the development of technology to recover these materials, the experts consulted recognize that currently recycling is far from reaching the thresholds proposed by the 25% standard and that, in reality,would barely cover more than 10-15% of production needs," says López.

The difficulties are numerous, but one of the main ones is the lack of technological development for recycling certain elements. Added to this is the high cost of some recovery processes. A clear example is the rare earths used in the manufacture of permanent magnets for wind turbine motors: currently, the recycling rate is less than 1%. "Many technological solutions never make it out of the laboratory because they are not economically viable for the business sector," notes Patricia Córdoba, researcher at the Institute for Environmental Diagnosis and Water Studies (IDAEA-CSIC) and project coordinator. RECOPPSHe explains that it can take up to fifteen years from the development of an idea to its commercial application. "A process that works perfectly in the laboratory may not be efficient at the pilot level," he warns. One reason is that managing the waste generated during the recovery of materials—often complex and, in some cases, highly toxic—can be much more costly and complicated than simply using new raw materials.

Another difficulty is that many products have not yet reached the end of their useful lifeFor example, solar panels or wind turbines last about 25 to 30 years. This means that, for the time being, the volume available for recycling is still insufficient.

To solve some of these problems, the experts consulted advocate promoting eco-design: "A mobile phone can have around 30 elements, but they are in very small and mixed concentrations. Legislation is needed to require manufacturing companies to design electronic devices to make the most efficient use of materials," Córr points out.

Another strategy is to seek alternative materials to meet critical demand. Researchers such as M. Rosa Palacín and Alexandre Ponrouch, from ICMAB-CSIC, are exploring ways to manufacture energy-storage batteries using sodium, calcium, or magnesium instead of lithium. "The difficulty in replacing one metal with another is that they don't have exactly the same properties, but they may have other advantages, such as price or abundance," explains Palacín.

Experts also warn that although recycling could soften the growth of mining extraction and therefore needs to be promoted, will not replace it in current demand scenarios. In this regard, Mariana Walter points out thatit would also be necessaryReducing consumption and deciding more democratically how we use these resources: "Sectors such as the military industry require a lot and compete with other uses, such as renewables." In fact, it is estimated that a 1% reduction in global consumption could save annually 840 million tons of metals, fossil fuels, minerals and biomass, and 39 trillion liters of water. For her part, researcher Abigail Jiménez-Franco argues that Europe must continue investing in its own mining industry, with strict regulations that reduce its environmental impact and guarantee decent working conditions. "It's preferable to do it here with safeguards than to continue transferring its impacts to the Global South," she asserts. She also proposes further strengthening recycling and ensuring that imports come from fair trade channels.