Effects of Basicity and Al2O3 Content on the Chemistry of Phases in Iron Ore Sinter Containing ZnO

Abstract

The effects of basicity and Al 2 O 3 content on the chemistry of phases in iron ore sinter containing ZnO were investigated by Rietveld analysis of the X-ray diffraction (XRD) patterns. Bulk composition analysis was carried out using inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and wet-chemical analysis. The composition of each phase was investigated using a scanning electron microscope-energy dispersive X-ray analyzer (SEM-EDX). It was found that ZnO exists in the franklinite and the silicoferrite of calcium and aluminum (SFCA) phases. With increasing ZnO content, the phase fraction of the franklinite increased, while the fraction of SFCA slightly increased. When ZnO content was fixed at 1 wt pct and basicity increased, the fraction of franklinite decreased and that of SFCA increased. Here, the solubility of ZnO in the SFCA increased. As the Al 2 O 3 content increased, the fraction of franklinite decreased and that of SFCA increased, while ZnO content in the SFCA did not change significantly.

A Short Review of the Effect of Iron Ore Selection on Mineral Phases of Iron Ore Sinter

“…Table 5 shows a compilation of chemical compositions and phase fractions of typical iron ore sinters from the literature. Figure 4a shows a typical electron microscope image of the cross-section of a synthetic iron ore sinter reported by Park et al [50]. Here, SFCA shows a columnar morphology, and it was formed between residual hematite particles.…”

“…Apparently, SFCA-I has a platy microstructure that is finer than the microstructure of SFCA. In Table 5, chemical compositions and phase fractions of iron ore sinters are listed; the chemical compositions and fractions were determined through Rietveld analysis [50,55,56]. Figure 6 shows the effects of basicity (CaO/SiO2) and Al2O3 content on the SFCA fraction in the iron ore sinter.…”

“…7. [50]. They used information on Hamilton's crystal structure parameters to evaluate the atom occupancy variation.…”

“…Recently, Park et al reported the substitution of Zn at the M12 site in SFCA [50]. They used information on Hamilton's crystal structure parameters to evaluate the atom occupancy variation.…”

Distinct Difference in High-temperature Characteristics between Limonitic Nickel Laterite and Ordinary Limonite

“…[30][31][32] The formation characteristics of SFCA is mainly dominated by the factors such as the chemical compositions of iron ores, sinter basicity, gas atmosphere and cooling rate. [33][34][35][36][37] Normally, the higher sinter basicity, iron grade and SiO 2 content of iron ores and oxygen partial pressure contribute to the formation of SFCA while the excessive Al 2 O 3 and MgO contents of iron ores and overquick cooling rate during sintering are adverse to the formation of SFCA. In general, SFCA can be divided into two types on the basis of the composition, morphology and crystal structure, i.e.…”