Recovery of metals from rare-earth-containing tailings and slags : alleviating material constraints in renewable energy systems
Yang, Taiyu (2025)
Diplomityö
2025
School of Energy Systems, Ympäristötekniikka
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2025061871739
https://urn.fi/URN:NBN:fi-fe2025061871739
Tiivistelmä
The global transition to renewable energy systems (RES) is increasingly constrained by the limited availability of critical raw materials. Particularly, rare earth elements (REEs) are indispensable for technologies such as wind turbines, electric vehicles (EVs), and energy storage systems, but the rare minable resources are controlled by only a few countries, especially China. Meanwhile, the mining and metallurgical industries produce vast quantities of waste in the form of tailings and slags, many of which are found to contain unrecovered REEs. This thesis investigates the potential of REE recovery from these secondary resources to alleviate supply constraints and reduce environmental burdens.
From an extensive review of literature, the different types of REE-bearing tailings and slags are identified, and the specific REE compositions and quantities are surveyed. The available recovery methods are assessed in terms of their technical feasibility, recovery efficiency, economic viability, and environmental impacts. Two scenarios are modeled to estimate the theoretical contribution of REE recovery from tailings and slags to global REE supply.
Previous studies show that many bench-level experiments have achieved over 90% recovery efficiency with different recovery methods. The estimation results suggest that secondary resources hold recovery potential of approximate one third of the current total REE reserve, and some of the major secondary sources can be widely found outside of the currently dominant REE suppliers. However, technical limitations, environmental risks, and economic challenges remain barriers to industrial-scale adoption.
By providing a systematic overview of REE recovery opportunities from waste streams, this thesis contributes to the development of sustainable resource strategies that support the global energy transition while mitigating the environmental footprint of mining waste.
From an extensive review of literature, the different types of REE-bearing tailings and slags are identified, and the specific REE compositions and quantities are surveyed. The available recovery methods are assessed in terms of their technical feasibility, recovery efficiency, economic viability, and environmental impacts. Two scenarios are modeled to estimate the theoretical contribution of REE recovery from tailings and slags to global REE supply.
Previous studies show that many bench-level experiments have achieved over 90% recovery efficiency with different recovery methods. The estimation results suggest that secondary resources hold recovery potential of approximate one third of the current total REE reserve, and some of the major secondary sources can be widely found outside of the currently dominant REE suppliers. However, technical limitations, environmental risks, and economic challenges remain barriers to industrial-scale adoption.
By providing a systematic overview of REE recovery opportunities from waste streams, this thesis contributes to the development of sustainable resource strategies that support the global energy transition while mitigating the environmental footprint of mining waste.