Long-Term Strategies for Increased Recycling of Automotive Aluminum and Its Alloying Elements

Abstract

Aluminum recycling currently occurs in a cascading fashion, where some alloys, used in a limited number of applications, absorb most of the end-of-life scrap. An expected increase in scrap supply in coming decades necessitates restructuring of the aluminum cycle to open up new recycling paths for alloys and avoid a potential scrap surplus. This paper explores various interventions in end-of-life management and recycling of automotive aluminum, using a dynamic substance flow analysis model of aluminum and its alloying elements with resolution on component and alloy level (vehicle-component-alloy-element model). It was found that increased component dismantling before vehicle shredding can be an effective, so far underestimated, intervention in the medium term, especially if combined with development of safety-relevant components such as wheels from secondary material. In the long term, automatic alloy sorting technologies are most likely required, but could at the same time reduce the need for magnesium removal in refining. Cooperation between the primary and secondary aluminum industries, the automotive industry, and end-of-life vehicle dismantlers is therefore essential to ensure continued recycling of automotive aluminum and its alloying elements.

Quality Evaluation of Remelted A356 Scraps

“…However, it was indicated that the difficulties in refining process of scrap leads to the strategies where primary alloy supply is prefered. Similar calculations were also made by Cullen [24] and Lovik et al [25]. Gaustad et al [26] has reviewed the techniques of removing unwanted elements and general recycling issues.…”

Material efficiency strategies to reducing greenhouse gas emissions associated with buildings, vehicles, and electronics—a review

“…In a scenario to 2050, developed by Modaresi et al [153], steel-intensive light-weighting can reduce mass by 11% compared to business-as-usual, reducing life cycle emissions by 5%, while an aluminum-extreme scenario reduces mass by 26% and results in life cycle emission reductions of 8%. Through alloy-specific recycling of the aluminum components, the additional energy use for producing aluminum components can be more than offset [154].…”

“…Such downcycling constitutes itself an energy loss: pig iron production causes emissions of 1.5 kg CO 2 equivalent per kg iron, while alloying elements range from similar (1.9 kg CO 2 /kg metal for ferrochromium) to much higher (11 kg CO 2 /kg nickel from sulfide ores) [170], so that the emissions associated with highly alloyed steel can be significantly higher than those of construction steel. Further, alloying elements and other metals mixed in as part of the shredding process become contaminants that compromise the quality of the material in question even for bottom applications, potentially leading to a future where secondary material needs to be discarded [154,171]. Copper and tin contamination limits the usefulness of secondary steel and scenarios foresee a possible saturation of the steel stock with copper within material tolerances, impeding further recycling [171].…”

Synthesis of 3D Flower‐like Nanocomposites of Nitrogen‐Doped Carbon Nanosheets Embedded with Hollow Cobalt(II,III) Oxide Nanospheres for Lithium Storage

“…Thus, seeking and developing suitable alternatives to graphite have become the focus of LIB research . Recently, mesoporous carbon materials, alloying materials, and transition‐metal oxides have been developed to increase the specific capacity of anode materials. Among these materials, the high theoretical capacity, nature abundance, low cost, and low toxicity of transition‐metal oxides such as cobalt oxides have made them attractive for use in lithium storage .…”