AsianScientist (Feb. 2, 2018) – Scientists in Japan have demonstrated that the recycling rates of alloy elements can be substantially increased by sorting scrap car parts. Their findings are published in Environmental Science & Technology.
While Japan mandates automobile recycling, scrap car parts are usually lumped together as iron. This means specific alloy elements present in the scrap, such as manganese, chromium, nickel and molybdenum, are not optimally recycled.
In the present study, researchers at Tohoku University, Japan, analyzed the composition of scrap car parts and what they could be reused for. They demonstrated that between 94 and 99 percent of alloy elements could be recycled from these disposed materials.
They estimated that when melted down in electric arc furnaces and remade into steel products such as coils, plates and bars, scrap metal can replace about 10 percent of the new material used by steelmakers. This translates to huge savings—steelmakers would save up to 15.2 percent of their expenditure on alloys, amounting to 31.6 billion yen (US$287 million). Greenhouse gas emissions associated with obtaining new material could also be reduced by 28.3 percent.
The authors noted that their methodology can be applied globally and in other industries to optimize costs and emissions so as to make the most of recycling efforts. This methodology will also help advance efforts to establish a circular economy, one that addresses products from cradle to grave and minimizes harmful environmental impacts.
Despite the potential savings, the authors anticipate that improving car scrap recycling systems will likely require policymakers to support the development of new automatic sorting technologies for recyclers, as well as incentivize steelmakers to purchase sorted scrap at fair prices.
The article can be found at: Ohno et al. (2017) Optimal Recycling of Steel Scrap and Alloying Elements: Input-Output based Linear Programming Method with Its Application to End-of-Life Vehicles in Japan.
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Source: Tohoku University; Photo: Pixabay.
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