Controlled Preparation of Different Proportions of Metal Fe-Mn from Waste Mn Ferrite by Molten Salt Electrolysis

Shiyuan Liu,Lijun Wang

doi:10.3390/pr8121647

Abstract

A novel method for efficiently recovering Fe and Mn from waste Mn ferrite by molten salt electrolysis is firstly proposed. The electrolysis of molten salt (MnCl2 (1.06 wt%)-FeCl3 (2.69 wt%)-NaCl-KCl) was performed at 800 °C. The phase of product at 2.0 V was metal Fe while metal Fe and Mn were obtained by molten salt electrolysis at 2.3 V. The Fe/Mn mass ratio of electrodeposited products at 2.0 V and 2.3 V were 687 and 3.2, respectively. The different proportions of metal Fe-Mn were prepared by controlling the electrolytic voltages. This new method can realize direct transformation of waste Mn ferrite to Fe-Mn alloy.

Highlights

Ferrites are widely used in the electronics industry [1,2]
We reported that molten salt chlorination destroyed the spinel structure of (Mn,Fe)(Cr,V)2 O4 with AlCl3, and MnCl2, CrCl3, FeCl2 and VCl3 were obtained [12,13]
In order to recover the Fe and Mn in waste ferrite, we propose that the new process includes the following two steps: chlorination of waste Mn ferrite with AlCl3 and the separation of Fe and Mn by molten salt electrolysis

Summary

Introduction

Ferrites are widely used in the electronics industry [1,2]. Since 2008, more than 250,000 tons ofMn-Zn ferrite have been produced annually in China [3]. A large amount of waste ferrite is generated in the manufacturing process of ferrite [3]. Traditional processes for treating waste ferrite included the following procedures: H2 SO4 leaching, reducing, purification, co-precipitation, ball milling, sintering, etc. The reducing agent used in traditional processes is generally high-purity reduced iron powder [5]. We reported that molten salt chlorination destroyed the spinel structure of (Mn,Fe)(Cr,V) O4 with AlCl3 , and MnCl2 , CrCl3 , FeCl2 and VCl3 were obtained [12,13]. In order to recover the Fe and Mn in waste ferrite, we propose that the new process includes the following two steps: chlorination of waste Mn ferrite with AlCl3 and the separation of Fe and Mn by molten salt electrolysis.

Methods

Results

Discussion

Conclusion