Recycling is a key pillar in global initiatives striving towards a more sustainable society. As outlined by the United Nation’s Sustainable Development Goals: 17 goals to transform our world, “responsible consumption and production” is at the core of a circular economy and plays a critical role in mitigating climate change.
When it comes to recycling, what sets metals like nickel apart from other raw materials?
First of all, nickel can be infinitely recycled without loss of quality. Generally, metals from primary raw materials cannot be distinguished from recycled metals. As a result, special emphasis is put on ensuring that as much nickel as possible is collected and recycled at its end-of-life.
Secondly, with its 68 % recycling rate, nickel is amongst the metals with the highest recycling efficiencies. This means that more than two-thirds of all nickel in consumer products is recycled once these products reach their end-of-life. The recycled nickel enters a new life-cycle, much of it as stainless steel and around 15 % in the carbon steel loop.
Yet data analysis shows that 17 % of nickel is still not recycled.
Room for further efficiency
Research has played a key role in measuring and assessing recycling rates. The goal is to capitalise on future opportunities to further reduce the amount of nickel ending up in landfill.
The UNEP International Resource Panel, launched in 2007 to build and share the knowledge needed to improve our use of resources worldwide, published a report on the recycling of metals in 2011.
Under the lead of Professor Thomas Graedel from Yale University, a team of experts from academia, industry and civil society examined the recycling of more than 50 metals. The report assessed recycling efficiencies for base metals, precious metals and minor metals. The work shows where the greatest needs are to improve recycling.
Professor Graedel’s team notes, “There are significant differences in recycling efficiencies of the metals assessed: on the one hand, base metals such as carbon steel have high recycling efficiencies, while rare earth elements are currently hardly recycled. Different factors play a role, such as use patterns, whether there is an economic incentive to collect, or if there is an available collection and recycling infrastructure.”
Nickel and stainless steel are amongst the best investigated raw materials in view of stock (amount of nickel currently in use in society) and flow modeling and recycling. One of the researchers involved in drafting the UNEP report was Dr. Barbara Reck, a senior researcher in Professor Graedel’s team at Yale University. With support from Team Stainless and the Nickel Institute, she has spent several years investigating the flows and stocks of nickel and stainless steel. Her work has been published in several peer-reviewed journals. The models were compiled for the reference years 2000, 2005 and 2010. Currently, Dr. Reck is finalising an update of the nickel stocks and flow models.
“The work will show the stocks and flow models and recycling rates for 2015,” explains Dr. Mark Mistry, the Nickel Institute’s expert on life-cycle analysis for nickel. “Trends which can be seen between the first investigation in 2000 and 2015 show the increased relevance of Asia in nickel supply and use, the fast-growing stocks of nickel in society and also indicate a trend in improved recycling of nickel.”
Similar work done for stainless steel confirms these trends for the major first use of nickel. The work is expected to be published late 2018/early 2019.
Industry plays role
There is also a role for industry to play. The amount of nickel going inadvertently into the carbon steel loop shows potential to be further reduced. For example, improved sorting systems are critical to ensuring that more nickel-
containing goods such as stainless steel are separated from carbon steel scrap.
The good news is, working together to increase nickel recycling and reduce waste is a tangible goal that is creating real results toward sustainability.