Removal of iron and aluminum from hydrometallurgical NMC-LFP recycling process through precipitation
Loading...
Access rights
openAccess
publishedVersion
URL
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
Date
Major/Subject
Mcode
Degree programme
Language
en
Pages
11
Series
Minerals Engineering, Volume 218, pp. 1-11
Abstract
There is a need to develop removal strategies for typical battery impurities–iron and aluminum–from actual hydrometallurgical recycling solutions. In this work, the investigated solution originated from lithium nickel manganese cobalt oxide (NMC) rich black mass, while iron phosphate (LFP) was used as an in situ reductant. It was found that the presence of phosphate ions supported selective iron precipitation already at pH = 2.0 (T = 60 °C, t = 3 h, NaOH), with nearly complete iron removal (97.8 %). The precipitate was rich in iron (21.5 wt%) and phosphorus (13.4 wt%); it also contained 0.7 wt% Ni and 0.3–0.4 wt% Mn, Co, Al, and Li. It is suggested that the presence of phosphate in minor amounts may cause this co-precipitation of battery metals. With the aim of combined precipitation of iron (100 %) and aluminum (91.0 %), the pH was increased up to 4.5. Although 90.8 % of fluoride precipitated, the remaining fluorides may have kept the aluminum partially in soluble form as Al-F complexes. The formed precipitate had lower iron (18.4 wt%) and phosphorus (11.4 wt%) content, whereas the impurity contents and thus the battery metals losses were slightly higher: Ni, Mn, Co, Al, and Cu were each between 1.1–1.9 wt% and Li and F < 1 wt%. In the precipitates investigated, iron was found predominantly as iron phosphate (FePO4), whereas a minor fraction also precipitated as iron fluoride (FeF3). The precipitated aluminum existed mainly as AlOOH. The results presented here will help to build iron and aluminum removal strategies for industrial battery recycling solutions, and also provide insights into the dominant iron and aluminum phases forming the precipitates.Description
Publisher Copyright: © 2024 The Authors
Other note
Citation
Zou, Y, Chernyaev, A, Seisko, S, Sainio, J & Lundström, M 2024, 'Removal of iron and aluminum from hydrometallurgical NMC-LFP recycling process through precipitation', Minerals Engineering, vol. 218, 109037, pp. 1-11. https://doi.org/10.1016/j.mineng.2024.109037