TITLE:
Effect of MnO on Mineral Composition of CaO-SiO2-MgO-Al2O3-Cr2O3 System
AUTHORS:
Yue Yu, Jianli Li, Mengxiong Li, Zhengliang Xue
KEYWORDS:
Mineral Phase, MnO, Leaching, Chromium, Spinel, Stainless Steel Slag
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.5 No.3,
May
26,
2017
ABSTRACT: The chromium leaching from stainless steel slag highly depends on the occurrence of chromium. The effect of MnO on the mineral composition of stainless steel slag was investigated through CaO-SiO2-MgO-Al2O3-Cr2O3 synthetic slags. The experiments were performed in a conductive furnace, and the samples collected during tests were analyzed using X-ray Diffrac-tion (XRD) and Scanning Electron Microscope (SEM) equipped Energy Dispersive Spectroscopy (EDS). The results show that the addition of MnO significantly reduces the solidus temperature of oxide systems from 1204oC to 950oC, promotes the spinel precipitation and increases the size of spinel crystals. The fraction of chromium contained in non-spinel mineral phases decreases and the amount of larnite dissolved into spinel phase slightly reduces with the content of MnO increasing. In addition, the amorphous phase forms when the content of MnO is up to 6 wt%. Hence, the addition of MnO is beneficial to suppress chromium leaching from slag.