Two reports from the United Nations Environment Programme (UNEP) have estimated that global demand for metals could rise by three to nine times current levels, prompting calls for a rethink of recycling practices.

The reports, 'Environmental Risks and Challenges of Anthropogenic Metals Flows and Cycles' and 'Metal Recycling: Opportunities, Limits, Infrastructure', were launched yesterday (24 April) in Berlin at high-level talks titled ‘Resource Efficiency and Sustainable Management of Metals’. The former covers how recycling can lessen the potential environmental impact of metals, whilst the latter details improvements needed to the recycling of metals in the 21st century.

‘Sophisticated approach’ urgently needed

UNEP Executive Director Achim Steiner pointed to rising levels of metal usage among emerging economies as a matter of concern, arguing that as demand for metals from these nations reaches that of developed nations, global metal supplies will become strained. He asserted that improved metal recycling efficiency is needed to counteract this problem.

“A far more sophisticated approach is urgently needed to address the challenges of recycling complex products, which contain a broad variety of interlinked metals and materials", he stated.

"Product designers need to ensure that materials such as rare earth metals in products ranging from solar panels and wind turbine magnets to mobile phones can still be recovered easily when they reach the end of their life."

Indeed, mobile phones provide an especially challenging prospect owing to their complexity. According to the UNEP, a mobile phone can contain more than 40 different elements, including base metals such as copper and tin and precious and platinum-group metals such as silver, gold and palladium. Moreover, this growing complexity is reflected across a wide range of modern products.

This presents a number of environmental problems, in particular that if products cannot easily be recycled, then increased emphasis is put on primary production, which can result in increased emissions. For example, the production and use of metals can require seven to eight per cent of the global energy supply. According to Reuters, mining can use 10 to 100 times more energy than the recycling of metals.

Recycling alone ‘will not be sufficient’

In a joint statement, Ernst Ulrich von Weizsäcker and Ashok Khosla, co-chairs of the UNEP’s International Resource Panel said: "An increased share of recycling of metals can be expected to alleviate some of the adverse environmental pressures from the use and production of metals.,

"However, increased recycling rates alone will not be sufficient but need to be accompanied by a levelling off of the demand curve for metals."

Yet the UNEP states that the demand for metals is likely to remain strong, both in developing nations undergoing rapid industrialisation and in already-developed nations, whose modern technology requires a constant supply of metals. Furthermore, despite cutting greenhouse gas emissions, renewable energy generation is likely to put further strain on metal supplies, as the technologies require more metal than fossil-fuel energy production.

Change in thinking required

The UNEP therefore encourages greater recycling of metals to meet these challenges. It asserts: ‘Theoretically, metals can be recycled almost indefinitely, thus presenting a valuable opportunity to reduce environmental degradation, energy and water use and contribute to the transition to a low-carbon, resource-efficient green economy.’

It estimates that the amount of waste electrical and electronic equipment (WEEE) that is not recycled is high, standing at 20 to 50 million tonnes globally per year. The figure stands at 12 million tonnes for Europe, comprising three to seven kilogrammes per person.

However, the complexity of many products means that increasing recycling rates can be problematic. In light of this, the UNEP recommends: ‘[A] global move from a material-centric to a product-centric approach, in which recycling targets specific components of a product and their complexity at its end of life (EoL) and devises ways to separate and recover them, is essential.’

The 'Metal Recycling: Opportunities, Limits, Infrastructure' report argues that the focus must move away from the individual materials contained within products and instead move towards optimising the recycling of products as a whole. This shift in thinking must encompass ‘everyone in the value chain’, from producers to recyclers to consumers.

Increasing the recycling of EoL products could be achieved through economic incentives, according to the UNEP, provided they ‘align with long-term economic goals, such as conserving critical metal resources for future applications, even if their recovery may be currently uneconomic’.

"Our aim must be to break the raw materials spiral by using materials more consciously", said German Federal Environment Minister Peter Altmaier. "In Germany, raw materials are already applied much more efficiently than 10 years ago. But we can achieve even more: by 2020 we want to double raw materials efficiency compared to 1994 levels."

Recommendations

The reports contain a number of recommendations, including:

• Certified systems based on best available technologies (BATs) and other measures increasing energy and entropy efficiency for mining as well as recycling industries need to be applied on a global level;
• A shift is required away from weight-based targets, which hinder rather than promote recycling of the many critical elements in complex products, usually present in very low concentrations. Priorities have to be set for different metals, such as base metals, special metals, critical-technology metals, etc;
• Policy targets for recycling must account for the loss of metals due to mixing, must not exceed physical, technological and thermodynamic limits, and should not prioritise one or two metals at the inadvertent expense of others;
• System optimisation and design can further increase recycling rates and decrease environmental impacts;
• Policy goals for the recycling system must dovetail with economic drivers;
• Primary production energy efficiency increases can be achieved by improved process efficiency and use of waste streams (fly ash, sludge, slags, precipitates and suchlike) as sources of metals.

Read the Environmental Risks and Challenges of Anthropogenic Metals Flows and Cycles report and the Metal Recycling: Opportunities, Limits, Infrastructure report.