Green Extractants in Assisting Recovery of REEs: A Case Study

Dorota Kołodyńska; Katarzyna Burdzy; Steffi Hunger; Andreas Aurich; Yongming Ju

doi:10.3390/molecules28030965

Green Extractants in Assisting Recovery of REEs: A Case Study

Molecules. 2023 Jan 18;28(3):965. doi: 10.3390/molecules28030965.

Authors

Dorota Kołodyńska¹, Katarzyna Burdzy¹, Steffi Hunger², Andreas Aurich², Yongming Ju^{3

4}

Affiliations

¹ Department of Inorganic Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University, Maria Curie-Skłodowska Sq. 2, 20-031 Lublin, Poland.
² Department Centre for Environmental Biotechnology (UBZ), Helmholtz-Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
³ Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment (MEE), Nanjing 210042, China.
⁴ The Key Laboratory of Water and Air Pollution Control of Guangdong Province, South China Subcenter of State Environmental Dioxin Monitoring Center, South China Institute of Environmental Sciences, Ministry of Ecology and Environment (MEE), Guangzhou 510655, China.

Abstract

The recycling of REEs from the end of life (EoL) products, such as nickel metal hydride batteries (NiMH), offers great opportunities for their supply in Europe. In the presented paper, the application of 'green' extractants such as citric (CA), metatartaric (TA), and ethylenediaminedisuccinic acid (EDDS) (also with H₂O₂ addition) for the recovery of REEs was studied. The studies were conducted considering the effects of the phase contact time, the initial concentration of CA, TA, and EDDS, as well as H₂O₂, pH, and temperature. It was found that the addition of TA to the CA solution meant that higher rates of metal ion binding and, thus, leaching was observed. The optimal conditions were obtained in the system: CA-TA and H₂O₂ for the concentration 0.6M-0.3 M-2%.

Keywords: citric acid; ethylenediaminedisuccinic acid; heavy metal ions; leaching; rare earth; tartaric acid.

Grants and funding

The authors are grateful for the financial support from the National Centre of Research and Development under Project No. POIR.04.01.01-00-0040/17-00 as well as Innovation Incubator 4.0.