Investigations on Indium and Zinc Leachabilities from Indium-Bearing Zinc Ferrite Improved by Planetary Ball Milling

In this work, a high-energy planetary mill was used to modify the chemical stability of indium-bearing zinc ferrite (indium-bearing ZnFe 2 O 4 , IBZF) and improve indium and zinc leachabilities. The microstructures, morphologies, and leaching characteristics of IBZF samples milled under different milling conditions were investigated by particle size analysis, Brunauer-Emmett-Teller specific surface area analysis, x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectra, Mössbauer spectrometry, and leaching experiments. The results show that the planetary ball milling has obvious effects on the microstructure and leaching characteristic of IBZF. Increasing the rotation speed and milling time cause the increase in the specific surface area, structure defects, and the breakage of the crystalline network, which result in a significant increase of indium and zinc extractions. In particular, the changes of crystal lattice structure induced by planetary ball milling play a key role in improving indium and zinc leachabilities from IBZF. The planetary ball milling also results in the redistribution of Zn 2+ and Fe 3+ in IBZF.