Magnetic Separation of Iron Ion
from Leaching Solution by Magnetic
Seeding in Hydrometallurgy
Tong Yue, Haisheng Han, Wei Sun, Yuehua Hu, Zhiyong Gao, Runqing Liu,
Li Wang, Lei Sun and Honghu Tang
Abstract Millions of tons of hazardous iron oxide residues are produced during the iron purification process of sulphate leaching solutions in nonferrous metals hydrometallurgy industry per year. The generated iron oxide residues, which
mainly contain goethite and gypsum precipitates adsorbing the hazardous elements
of arsenic, sulfur, zinc, and germanium, pose a great threat to the local ecological
environment and human health. A novel method for the treatment and recovery of
goethite and gypsum by synthetic magnetic nanoparticles (MNPs) such as α-Fe 3 O 4
and γ-Fe 2 O 3 are proposed to treat the residues efficiently and cost-effectively. MNPs
serve as the magnetic crystal nuclei of the goethite precipitates during the iron purification process, and the goethite and gypsum precipitates formed under this condition
can be separated in magnetic field. Subsequently, the magnetic crystal nuclei were
treated using a rod milling and magnetic collecting to obtain goethite precipitates
in order to minimize costs. Both precipitates can be digested as raw materials of
iron making and building materials, respectively. Additionally, we found that the
separation efficiency of the goethite and gypsum precipitates was much higher when
γ-Fe 2 O 3 was used as the crystal nuclei, indicating that the surface of γ-Fe 2 O 3 was
more favorable for the formation of goethite particles than α-Fe 3 O 4 .
Keywords Magnetic separation · Goethite precipitates · Gypsum precipitates ·
Hydrometallurgy
Tong Yue and Haisheng Han contributed equally to this work.
T. Yue · H. Han · W. Sun (B) · Y. Hu (B) · Z. Gao · R. Liu · L. Wang · L. Sun · H. Tang
School of Minerals Processing and Bioengineering, Central South University, Changsha 410083,
China
e-mail: sunmenghu@csu.edu.cn
Y. Hu
e-mail: hyh@csu.edu.cn
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_74
847
from Leaching Solution by Magnetic
Seeding in Hydrometallurgy
Tong Yue, Haisheng Han, Wei Sun, Yuehua Hu, Zhiyong Gao, Runqing Liu,
Li Wang, Lei Sun and Honghu Tang
Abstract Millions of tons of hazardous iron oxide residues are produced during the iron purification process of sulphate leaching solutions in nonferrous metals hydrometallurgy industry per year. The generated iron oxide residues, which
mainly contain goethite and gypsum precipitates adsorbing the hazardous elements
of arsenic, sulfur, zinc, and germanium, pose a great threat to the local ecological
environment and human health. A novel method for the treatment and recovery of
goethite and gypsum by synthetic magnetic nanoparticles (MNPs) such as α-Fe 3 O 4
and γ-Fe 2 O 3 are proposed to treat the residues efficiently and cost-effectively. MNPs
serve as the magnetic crystal nuclei of the goethite precipitates during the iron purification process, and the goethite and gypsum precipitates formed under this condition
can be separated in magnetic field. Subsequently, the magnetic crystal nuclei were
treated using a rod milling and magnetic collecting to obtain goethite precipitates
in order to minimize costs. Both precipitates can be digested as raw materials of
iron making and building materials, respectively. Additionally, we found that the
separation efficiency of the goethite and gypsum precipitates was much higher when
γ-Fe 2 O 3 was used as the crystal nuclei, indicating that the surface of γ-Fe 2 O 3 was
more favorable for the formation of goethite particles than α-Fe 3 O 4 .
Keywords Magnetic separation · Goethite precipitates · Gypsum precipitates ·
Hydrometallurgy
Tong Yue and Haisheng Han contributed equally to this work.
T. Yue · H. Han · W. Sun (B) · Y. Hu (B) · Z. Gao · R. Liu · L. Wang · L. Sun · H. Tang
School of Minerals Processing and Bioengineering, Central South University, Changsha 410083,
China
e-mail: sunmenghu@csu.edu.cn
Y. Hu
e-mail: hyh@csu.edu.cn
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_74
847