TY - JOUR
T1 - REE(III) recovery from spent NiMH batteries as REE double sulfates and their simultaneous hydrolysis and wet-oxidation
AU - Porvali, A.
AU - Agarwal, V.
AU - Lundström, M.
N1 - Funding Information:
We would like to thank Dr. Fupeng Liu for assistance with a SEM micrograph (Fig. 4A) and the associated EDX analysis (Fig. 4A), and also for valuable suggestions in the selective dissolution part of the study. We would also like to thank the funding bodies: MineWEEE (grant number 7100/31/2016), and BATCircle (grant number 4853/31/2018), both funded by Business Finland (BF). The research was also supported by the Strategic Research Council at the Academy of Finland, project CloseLoop (grant number 303454). RawMatTERS Finland Infrastructure (RAMI) funded by Academy of Finland is also greatly acknowledged.
Funding Information:
We would like to thank Dr. Fupeng Liu for assistance with a SEM micrograph ( Fig. 4 A) and the associated EDX analysis ( Fig. 4 A), and also for valuable suggestions in the selective dissolution part of the study. We would also like to thank the funding bodies: MineWEEE (grant number 7100/31/2016 ), and BATCircle (grant number 4853/31/2018 ), both funded by Business Finland (BF). The research was also supported by the Strategic Research Council at the Academy of Finland , project CloseLoop (grant number 303454 ). RawMatTERS Finland Infrastructure (RAMI) funded by Academy of Finland is also greatly acknowledged.
Publisher Copyright:
© 2020 The Authors
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/4/15
Y1 - 2020/4/15
N2 - Efficient recovery of REEs present in the battery waste is a modern problem that has proven to be difficult to solve in an efficient manner. The raw material investigated in the current study is mixed alkaline rare earth element (REE) double sulfate (DS) precipitate, originating from the sulfuric acid leachate of nickel-metal hydride battery (NiMH) waste. Typically, REE can be precipitated as a mixture of REE double sulfates, however the real challenge is the separation of REEs from each other's into pure fraction. The study elucidates the process by which the DS are transformed into hydroxides with simultaneous in-situ conversion of Ce(III) to Ce(IV) by air. Air flow rate (0–1 L/h), temperature (30–60 °C), liquid-solid ratio (L/S, 12.5–100 g/L), 3REE/NaOH mol ratio (1–1.6) and time (60–240 min) were varied in the study of oxidation and double sulfate conversion. Best oxidation achieved was 93% along near-complete dissociation of double sulfate matrix (52767 ppm Na reduced to 48 ppm Na). After parameter optimization, a larger batch was produced to conduct selective dissolution of REE(III) into HNO3 media, leaving concentrated impure Ce(OH)4 as the end product.
AB - Efficient recovery of REEs present in the battery waste is a modern problem that has proven to be difficult to solve in an efficient manner. The raw material investigated in the current study is mixed alkaline rare earth element (REE) double sulfate (DS) precipitate, originating from the sulfuric acid leachate of nickel-metal hydride battery (NiMH) waste. Typically, REE can be precipitated as a mixture of REE double sulfates, however the real challenge is the separation of REEs from each other's into pure fraction. The study elucidates the process by which the DS are transformed into hydroxides with simultaneous in-situ conversion of Ce(III) to Ce(IV) by air. Air flow rate (0–1 L/h), temperature (30–60 °C), liquid-solid ratio (L/S, 12.5–100 g/L), 3REE/NaOH mol ratio (1–1.6) and time (60–240 min) were varied in the study of oxidation and double sulfate conversion. Best oxidation achieved was 93% along near-complete dissociation of double sulfate matrix (52767 ppm Na reduced to 48 ppm Na). After parameter optimization, a larger batch was produced to conduct selective dissolution of REE(III) into HNO3 media, leaving concentrated impure Ce(OH)4 as the end product.
KW - Cerium
KW - Selective dissolution
KW - Spent NiMH batteries
KW - Wet oxidation
UR - https://www.scopus.com/pages/publications/85082835799
U2 - 10.1016/j.wasman.2020.03.042
DO - 10.1016/j.wasman.2020.03.042
M3 - Article
C2 - 32278217
AN - SCOPUS:85082835799
SN - 0956-053X
VL - 107
SP - 66
EP - 73
JO - Waste Management
JF - Waste Management
ER -