Mechanistic study on calcium ion diffusion into fayalite: A step toward sustainable management of copper slag

Ku，Jiangang1,2; Zhang，Lin1; Fu，Weng3; Wang，Shubin4; Yin，Wanzhong1; Chen，Huihuang1,5

2020

10.1016/j.jhazmat.2020.124630

JOURNAL OF HAZARDOUS MATERIALS   影响因子和分区

0304-3894

1873-3336

Copper slag, which contains Fe-rich fayalite (FeSiO), is a valuable solid waste that warrants further research in order to recover iron. Calcium oxide (CaO) can significantly enhance iron recovery from copper slag; however, the associated mechanism has not yet been explored. In this study, we investigated the interaction between CaO and FeSiO to obtain detailed understanding of the role of CaO in enhancing iron recovery. The presence of CaO was found to accelerate the decomposition of FeSiO via an ion-exchange-like process. Specifically, CaO dissociated into Ca(II) and a Ca-deficient CaO species at high temperatures. The Fe(II) ion at the M2 site of FeSiO was substituted by the released Ca(II) ion, resulting in the formation of [(FeCa)SiO]∙xFe(II). Subsequently, the substituted Fe(II) occupied the Ca vacancy in CaO to form (CaFe(II))O. The disproportionation of Fe(II) and the combination reaction between CaO and the SiO separated from FeSiO led to the generation of the final products, viz. FeO, FeO, and CaSiO. This study explains the specific role of CaO in decomposing FeSiO. It would not only provide theoretical guidance for iron recovery from copper slag but also present a new perspective on the recycling of valuable resources from many other smelting slags (e.g., iron slag, lead slag, and nickel slag).

Calcium oxide Interaction mechanism Iron recovery Solid waste Theoretical calculations

EI

英语

其他

20204909586004

Metal recovery ; Silica ; Silicon ; Decomposition ; Waste management ; Copper ; Ion exchange ; Ions ; Lime ; Magnetite ; Hematite ; Slags

Minerals:482.2 ; Copper:544.1 ; Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Chemical Reactions:802.2 ; Inorganic Compounds:804.2

ENGINEERING

2-s2.0-85097077665

Scopus

1.College of Zijin Mining,Fuzhou University,Fuzhou,350116,China
2.Fuzhou University-Zijin Mining Group Joint Research Center for Comprehensive Utilization of Mineral Resources,Fuzhou University,Fuzhou,350116,China
3.School of Chemical Engineering,The University of Queensland,Brisbane,4072,Australia
4.School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
5.Hefei National Laboratory for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei,230026,China

Ku，Jiangang,Zhang，Lin,Fu，Weng,et al. Mechanistic study on calcium ion diffusion into fayalite: A step toward sustainable management of copper slag[J]. JOURNAL OF HAZARDOUS MATERIALS,2020,410.

Ku，Jiangang,Zhang，Lin,Fu，Weng,Wang，Shubin,Yin，Wanzhong,&Chen，Huihuang.(2020).Mechanistic study on calcium ion diffusion into fayalite: A step toward sustainable management of copper slag.JOURNAL OF HAZARDOUS MATERIALS,410.

Ku，Jiangang,et al."Mechanistic study on calcium ion diffusion into fayalite: A step toward sustainable management of copper slag".JOURNAL OF HAZARDOUS MATERIALS 410(2020).