Surface behaviour of magnesium chloride-coated iron ore sinter

Abstract

The coating of sinter particles with magnesium chloride rendered a less reducible material at low temperature, and simultaneously enhanced mechanical strength. The joint use of scanning electron microscopy (SEM) and energy dispersive analyses of the X-rays (EDAX) emitted by the solid revealed the magnesium atoms to be almost uniformly distributed on the sinter surface. However, X-ray photoelectron spectroscopy (XPS) provided an extremely useful tool for understanding the chemical reaction, largely confined to the surface, when the sinter was heated at high temperatures. A model which assumes solid-state reaction between MgO and Fe₂O₃ to form a surface spinel-like MgFe₂O₄ compound has been proposed to describe that process in both salt-coated sinter and salt: physical mixture sinter preparations.