Solubility of Sm2(SO4)3 and Nd2(SO4)3 in sulfate solutions

Yuezhou Wei; Nobuaki Sato; Michio Nanjo

Solubility of Sm2(SO4)3 and Nd2(SO4)3 in sulfate solutions

Yuezhou Wei, Nobuaki Sato, Michio Nanjo

Center for Mineral Processing and Metallurgy (CMPM)

Research output: Contribution to journal › Article › peer-review

11 Citations (Scopus)

Abstract

A new process consisting of fractional crystallization and electrowinning from sulfate solution is proposed for recycling rare earth magnet scrap which contains about 30% Sm or Nd and 50-60% Co or Fe. With increasing temperature, the CoSO₄ and FeSO₄ solubilities in water increase, while Sm₂ (SO₄)₃ and Nd₂(SO₄)₃ solubilities decrease sharply. From the results of X-ray diffraction and thermal analysis, the forms of equilibrating solid phases were identified as Sm₂(SO₄)₃ · 8H₂O from 0 to 80°C, Nd₂(SO₄)₃ · 8H₂O with 0-80°C and Nd₂(SO₄)₃ · 5H₂O at 80°C, respectively. In increasing the SO₄^2-(H₂SO₄, CoSO₄, FeSO₄), the solubility - [SO₄^2-] curves of Sm₂(SO₄)₃ and Nd₂(SO₄)₃ show the maximum value which shifts to higher SO₄^2-concentration with temperature.

Original language	English
Pages (from-to)	965-970
Number of pages	6
Journal	Shigen to sozai
Volume	105
Issue number	12
Publication status	Published - 1989 Nov 1

ASJC Scopus subject areas

Engineering(all)

Cite this

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title = "Solubility of Sm2(SO4)3 and Nd2(SO4)3 in sulfate solutions",

abstract = "A new process consisting of fractional crystallization and electrowinning from sulfate solution is proposed for recycling rare earth magnet scrap which contains about 30% Sm or Nd and 50-60% Co or Fe. With increasing temperature, the CoSO4 and FeSO4 solubilities in water increase, while Sm2 (SO4)3 and Nd2(SO4)3 solubilities decrease sharply. From the results of X-ray diffraction and thermal analysis, the forms of equilibrating solid phases were identified as Sm2(SO4)3 · 8H2O from 0 to 80°C, Nd2(SO4)3 · 8H2O with 0-80°C and Nd2(SO4)3 · 5H2O at 80°C, respectively. In increasing the SO42-(H2SO4, CoSO4, FeSO4), the solubility - [SO42-] curves of Sm2(SO4)3 and Nd2(SO4)3 show the maximum value which shifts to higher SO42-concentration with temperature.",

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T1 - Solubility of Sm2(SO4)3 and Nd2(SO4)3 in sulfate solutions

AU - Wei, Yuezhou

AU - Sato, Nobuaki

AU - Nanjo, Michio

PY - 1989/11/1

Y1 - 1989/11/1

N2 - A new process consisting of fractional crystallization and electrowinning from sulfate solution is proposed for recycling rare earth magnet scrap which contains about 30% Sm or Nd and 50-60% Co or Fe. With increasing temperature, the CoSO4 and FeSO4 solubilities in water increase, while Sm2 (SO4)3 and Nd2(SO4)3 solubilities decrease sharply. From the results of X-ray diffraction and thermal analysis, the forms of equilibrating solid phases were identified as Sm2(SO4)3 · 8H2O from 0 to 80°C, Nd2(SO4)3 · 8H2O with 0-80°C and Nd2(SO4)3 · 5H2O at 80°C, respectively. In increasing the SO42-(H2SO4, CoSO4, FeSO4), the solubility - [SO42-] curves of Sm2(SO4)3 and Nd2(SO4)3 show the maximum value which shifts to higher SO42-concentration with temperature.

AB - A new process consisting of fractional crystallization and electrowinning from sulfate solution is proposed for recycling rare earth magnet scrap which contains about 30% Sm or Nd and 50-60% Co or Fe. With increasing temperature, the CoSO4 and FeSO4 solubilities in water increase, while Sm2 (SO4)3 and Nd2(SO4)3 solubilities decrease sharply. From the results of X-ray diffraction and thermal analysis, the forms of equilibrating solid phases were identified as Sm2(SO4)3 · 8H2O from 0 to 80°C, Nd2(SO4)3 · 8H2O with 0-80°C and Nd2(SO4)3 · 5H2O at 80°C, respectively. In increasing the SO42-(H2SO4, CoSO4, FeSO4), the solubility - [SO42-] curves of Sm2(SO4)3 and Nd2(SO4)3 show the maximum value which shifts to higher SO42-concentration with temperature.

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Solubility of Sm2(SO4)3 and Nd2(SO4)3 in sulfate solutions

Abstract

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