Two studies released by the UNEP-hosted International Resource Panel call for a move away from weight-based recycling targets which hinder rather than promote the recovery of 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 and targets must account for the loss of metals due to mixing and should not favour one or two metals at the inadvertent expense of others.

“Targets that go beyond what is thermodynamically possible are likely to fail,” the research notes, adding that “appropriate targets from a life-cycle perspective” must be considered.

In addition, system optimisation and design can further increase recycling rates and decrease environmental impacts.

The studies recommend that product designers should take life-cycle approaches as well as metallurgical knowledge and rigorous process recycling system simulation into account when designing new products.

Policy goals for the recycling system must also dovetail with economic drivers – the research points out that with so many operators in the collection and recycling industry, enforcement is unlikely to be sufficient by itself for determining the destination of metal-containing waste streams.

It also adds that primary production energy-efficiency increases can be achieved by improved process efficiency and use of waste streams such as fly ash, sludge, slags and precipitates as sources of metals.

Commenting on the study findings, German Federal Environment Minister Peter Altmaier said that the aim must be to break the raw materials spiral by using materials more consciously.

“In Germany, raw materials are already applied much more efficiently than ten years ago. But we can achieve even more – by 2020 we want to double raw materials efficiency compared to 1994 levels,” he said.

Maxine Perella

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