Scenario assessment of neodymium recycling in Japan based on substance flow analysis and future demand forecast

Abstract

With the increasing demand for energy-saving technologies, neodymium-iron-boron magnets have been widely utilized in high-efficiency motors. However, the reserves of neodymium, which is a rare earth element (REE), are limited; thus, a strategy for scaling up the REE supply is highly required. In this study, a scenario assessment was conducted to evaluate the effect of material recycling of neodymium from final product waste. Domestic substance flow analysis of neodymium was conducted by focusing on the waste flow of the final product. Moreover, the demand and waste of neodymium until 2050 were forecasted using various multivariate analysis methods. The results showed that the domestic waste of neodymium was forecasted to be 3866–4217 tons/year by 2050. However, material recycling of neodymium from final product waste may cause an additional increase in production by “circular economy rebound”. Considering that CO2 reduction has also been a global challenge to prevent global warming, the rebound effect was calculated. Therefore, a scenario assessment was conducted to evaluate the influence of this rebound effect by estimating the CO2 reduction. The results of this study are expected to make a significant contribution to the establishment of a new strategy for neodymium recycling.

Tracking Three Decades of Global Neodymium Stocks and Flows with a Trade-Linked Multiregional Material Flow Analysis

“…We have also adjusted the official production data of China by considering the unreported share (i.e., illegal mining or the output over or below the official production quota) based on estimates in the literature. , The shares of domestic consumption for semi-products (i.e., in eq , available in Supporting Information Tables S3–S7) were collected from Roskill . The shares of domestic consumption for final products ( in eq , available in Supporting Information Tables S3–S7), the lifetimes of final products ( in eq , available in Supporting Information Table S1), the market shares of commodities ( in eq , available in Supporting Information Table S8), and the Nd intensities of commodities ( in eq , available in Supporting Information Table S8) were all collected from literature. ,,, Due to lack of information on the shares of domestic consumption for final products in the US, we have estimated it using a bottom-up approach with data for US final use sectors from literature, report, or informed estimates (see details in Supporting Information Table S6).…”

“…41 The shares of domestic consumption for final products (P t ( ) i in eq 2, available in Supporting Information Tables S3−S7), the lifetimes of final products (L t t ( , ) in eq 5, available in Supporting Information Table S1), the market shares of commodities ( t MS ( ) i in eq 4, available in Supporting Information Table S8), and the Nd intensities of commodities (MI t ( ) i in eq 4, available in Supporting Information Table S8) were all collected from literature. 27,28,31,32 Due to lack of information on the shares of domestic consumption for final products in the US, we have estimated it using a bottom-up approach with data for US final use sectors from literature, 42 report, 41 or informed estimates (see details in Supporting Information Table S6).…”

“…Material flow analysis (MFA), also referred to as substance flow analysis when used for specific substances such as metals, is the most widely used methodology to track material stocks and flows over time. In recent years, MFA models have also been applied for Nd and its most significant product NdFeB magnets, both at the global (Nd) level and at the regional/national levels such as Europe (Nd), Japan (NdFeB), , Korea (Nd), China (Nd), − the Netherlands (Nd), and Denmark (NdFeB) . These studies provided a good understanding of Nd flows in specific countries, regions, or sectors.…”

Towards carbon neutrality: Improving resource efficiency of the rare earth elements in China

“…Finally, it is essential to improve the overall resource efficiency of rare earth elements by promoting circular economy. The total recycling rate of such rare earth elements-containing end-of-life products is less than 1% in China (Sprecher et al, 2015;Morimoto et al, 2021). Recently, Ge et al (2022) found that if the recycling rate reaches 40% in China, approximately 1728 tons of Sm can be recovered from in-use stocks, which can meet domestic demand for 2 years.…”

An Overview on Resource and Recovery Prospectives of the Critical Element Neodymium

“…Neodymium recovery, attributable to the accelerative requirement and insufficiency of supply, is necessary for our present-day living fashion and can be accomplished with the help of more systematic investigations and exploration of a broad range of eco-friendly and sustainable solvent extraction schemes. Scientific conception for recycling of critical metals is necessary for achieving proficient material circulation with the development of a methodical supply series [10][11][12]. The general extraction framework adopted for economic recovery of Nd is represented below in Fig.…”