Estimating increasing diversity and dissipative loss of critical metals in the aluminum automotive sector

As the demand for and consumption of products and services grow in the US, so does the concern for sustainable material usage. In the automotive industry, major sustainability issues revolve around advocating for improved fuel economy and the incorporation of materials with higher recyclability in order to reduce greenhouse gas (GHG) emissions. A popular strategy to achieve this in the automotive industry is light-weighting. Many studies in this field are focused on the environmental benefits of light-weighting, that is, how replacement of traditional steel in the automotive industry with aluminum, for instance, will help reduce the amount of CO2-eq emissions in the environment. The increasing use of aluminum in the industry for differing automotive applications broadens the range of alloying elements. Unfortunately, many of these elements are dissipatively lost and also deemed critical. Furthermore, some of the alloying elements accumulate as tramp (unwanted) elements in the secondary aluminum stream, hence posing as a barrier to effective recycling, thus leading to material and economic losses. We quantified the material losses and analyzed the economic losses attributed to the dissipation of critical metals and also examined the attendant accumulation of tramp elements in the recycled aluminum stream. Our results indicate that to achieve a more circular economy requires investment and further development of a) operational blending and batching strategies that comprehend alloying additions and the inherent variability of their actual composition, and b) economically feasible material identification and sorting technologies that will help in abating these material losses and associated economic losses.