Leaching of Sm, Co, Fe, and Cu from Spent SmCo Magnets Using Organic Acid

In this study, the Taguchi method was used to investigate the effect of citric acid and malic acid on the leaching of SmCo magnet waste. First, we used a L<sub>16</sub>(4<sup>5</sup>) orthogonal table to conduct experiments. Second, we conducted a factor effect analysis on th...

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Main Authors: Jian-Zhi Wang, Yi-Chin Tang, Yun-Hwei Shen
Format: Article
Language:English
Published: MDPI AG 2023-01-01
Series:Metals
Subjects:
Online Access:https://www.mdpi.com/2075-4701/13/2/233
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author Jian-Zhi Wang
Yi-Chin Tang
Yun-Hwei Shen
author_facet Jian-Zhi Wang
Yi-Chin Tang
Yun-Hwei Shen
author_sort Jian-Zhi Wang
collection DOAJ
description In this study, the Taguchi method was used to investigate the effect of citric acid and malic acid on the leaching of SmCo magnet waste. First, we used a L<sub>16</sub>(4<sup>5</sup>) orthogonal table to conduct experiments. Second, we conducted a factor effect analysis on the experimental results of the orthogonal table to understand the influence of temperature, acid concentration, solid–to–liquid ratio, time, and hydrogen peroxide on the leaching efficiency and we obtained the priority order of the factors affecting the leaching efficiency. The priorities of citric acid and malic acid were H<sub>2</sub>O<sub>2</sub> > temperature > S/L > time > acid and temperature > time > S/L > H<sub>2</sub>O<sub>2</sub> > acid, respectively. Finally, the optimal leaching parameters were obtained through confirmation experiments. For optimal leaching rates with citric acid, the amount of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) added was 2.0 vol.%, the temperature was 90 °C, the S/L ratio was 5 g L<sup>−1</sup>, the time was 135 min and the acid concentration was 1.0 mol L<sup>−1</sup>, resulting in leaching efficiencies of Sm, Co, Fe, and Cu of 87.62, 93.82, 97.10, and 92.84%, respectively. For optimal leaching rates with malic acid, the temperature was 80 °C, the time was 75 min, the S/L ratio was 7.5 g L<sup>−1</sup>, the amount of hydrogen peroxide added was 3.5 vol.%, and the acid concentration was 1.5 mol L<sup>−1</sup>, resulting in leaching efficiencies of Sm, Co, Fe, and Cu of 75.18, 74.58, 82.42, and 1.35%, respectively.
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spelling doaj.art-7bfe8717e0404d7085d92762b65c10872023-11-16T22:06:31ZengMDPI AGMetals2075-47012023-01-0113223310.3390/met13020233Leaching of Sm, Co, Fe, and Cu from Spent SmCo Magnets Using Organic AcidJian-Zhi Wang0Yi-Chin Tang1Yun-Hwei Shen2Department of Resources Engineering, National Cheng Kung University, Tainan 70101, TaiwanDepartment of Resources Engineering, National Cheng Kung University, Tainan 70101, TaiwanDepartment of Resources Engineering, National Cheng Kung University, Tainan 70101, TaiwanIn this study, the Taguchi method was used to investigate the effect of citric acid and malic acid on the leaching of SmCo magnet waste. First, we used a L<sub>16</sub>(4<sup>5</sup>) orthogonal table to conduct experiments. Second, we conducted a factor effect analysis on the experimental results of the orthogonal table to understand the influence of temperature, acid concentration, solid–to–liquid ratio, time, and hydrogen peroxide on the leaching efficiency and we obtained the priority order of the factors affecting the leaching efficiency. The priorities of citric acid and malic acid were H<sub>2</sub>O<sub>2</sub> > temperature > S/L > time > acid and temperature > time > S/L > H<sub>2</sub>O<sub>2</sub> > acid, respectively. Finally, the optimal leaching parameters were obtained through confirmation experiments. For optimal leaching rates with citric acid, the amount of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) added was 2.0 vol.%, the temperature was 90 °C, the S/L ratio was 5 g L<sup>−1</sup>, the time was 135 min and the acid concentration was 1.0 mol L<sup>−1</sup>, resulting in leaching efficiencies of Sm, Co, Fe, and Cu of 87.62, 93.82, 97.10, and 92.84%, respectively. For optimal leaching rates with malic acid, the temperature was 80 °C, the time was 75 min, the S/L ratio was 7.5 g L<sup>−1</sup>, the amount of hydrogen peroxide added was 3.5 vol.%, and the acid concentration was 1.5 mol L<sup>−1</sup>, resulting in leaching efficiencies of Sm, Co, Fe, and Cu of 75.18, 74.58, 82.42, and 1.35%, respectively.https://www.mdpi.com/2075-4701/13/2/233SmCo magnetTaguchi methodsleachingcitric acidmalic acid
spellingShingle Jian-Zhi Wang
Yi-Chin Tang
Yun-Hwei Shen
Leaching of Sm, Co, Fe, and Cu from Spent SmCo Magnets Using Organic Acid
Metals
SmCo magnet
Taguchi methods
leaching
citric acid
malic acid
title Leaching of Sm, Co, Fe, and Cu from Spent SmCo Magnets Using Organic Acid
title_full Leaching of Sm, Co, Fe, and Cu from Spent SmCo Magnets Using Organic Acid
title_fullStr Leaching of Sm, Co, Fe, and Cu from Spent SmCo Magnets Using Organic Acid
title_full_unstemmed Leaching of Sm, Co, Fe, and Cu from Spent SmCo Magnets Using Organic Acid
title_short Leaching of Sm, Co, Fe, and Cu from Spent SmCo Magnets Using Organic Acid
title_sort leaching of sm co fe and cu from spent smco magnets using organic acid
topic SmCo magnet
Taguchi methods
leaching
citric acid
malic acid
url https://www.mdpi.com/2075-4701/13/2/233
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AT yichintang leachingofsmcofeandcufromspentsmcomagnetsusingorganicacid
AT yunhweishen leachingofsmcofeandcufromspentsmcomagnetsusingorganicacid