Earth’s commercial and affordable zinc reserves are expected to be depleted in less than 50 years. Since electric arc furnace (EAF) dust contains a certain amount of Zn, recovery of Zn from EAF dust has become an important issue to assure a sustainable resource supply in the future. The key technical challenge is that Zn mainly occurs in EAF dust as ZnFe2O4, a very stable crystal which is difficult to reduce or leach. MgCl2 is believed to be effective in breaking the structure of ZnFe2O4. This work investigates the fundamentals of the reaction between MgCl2 and ZnFe2O4. Experiments show that Zn in ZnFe2O4 is chlorinated to ZnCl2 quickly with priority over Fe, implying the efficacy of MgCl2 in separating Zn and Fe in ZnFe2O4 by selective chlorination. Effects of MgCl2/ZnFe2O4 molar ratio and temperature on the reaction are clarified. Overuse of MgCl2 slows down the reaction and is detrimental to the selective chlorination of Zn. Temperature can effectively increase the reaction rate as well as the priority of chlorinating Zn. Utilization of MgCl2 could be high, because evaporation of MgCl2 is not as fast as the reaction with ZnFe2O4. According to these results, a new technology to recover Zn from EAF dust by using MgCl2 is proposed.
|Number of pages||13|
|Journal||Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science|
|Publication status||Published - 2022 Aug|
Bibliographical noteFunding Information:
This research is partially supported by the “Brain Pool Program” funded by the Ministry of Science and ICT through the National Research Foundation of Korea” (grant no. 2019H1D3A2A01058220). The authors thank Mrs. Yu Huang and Dr. Yinjuan Chen of Instrumentation and Service Center for Molecular Sciences at Westlake University for the assistance in the ICP-MS measurement.
© 2022, The Minerals, Metals & Materials Society and ASM International.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry