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

Junwoo Park,Jiwon Jeon,In-Kook Suh,Joonho Lee,Sanghan Son,Ramaraghavulu Rajavaram

doi:10.1007/s11663-020-01940-7

Abstract

The effects of basicity and Al2O3 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 Al2O3 content increased, the fraction of franklinite decreased and that of SFCA increased, while ZnO content in the SFCA did not change significantly.

Highlights

RECYCLING by-products generated from the integrated iron- and steelmaking industry has drawn attention from the vantage point of environmental and economic issues
The phase ratio was calculated with the values of lattice parameters of franklinite and Fe3O4.[40]. In X-ray diffraction (XRD) patterns, various calcium ferrite phases, such as CaFe2O4 (CF),[41] Ca2Fe2O5 (C2F),[42] and CaFe4O7 (CF2),[43] were detected, but the amount of each phase was less than 0.6 wt pct
The phase fractions, the composition of silicoferrite of calcium and aluminum (SFCA), and the substitution sites of Zn could be identified by using Rietveld analysis, wet-chemical analysis, and scanning electron microscope-energy dispersive X-ray analyzer (SEM-EDX) analysis

Summary

INTRODUCTION

While traveling with the gas stream to the upper part of the BF, Zn vapor is oxidized and condensed in the charged burdens or the refractory materials. As this sequence is repeated, ZnO is accumulated in the iron ore sinter and the refractory materials.[8,9] As ZnO content increases in the refractory material, damage of the refractory material may occur.[10] If we consider the maximum use of various dust ( BF dust and basic oxygen furnace dust[11,12] and electric arc furnace dust[13,14]), it is important to know the chemistry of iron ore sinter containing ZnO. With varying the bulk sample composition, the effects of basicity and Al2O3 content on the chemistry of the phases in the iron ore sinter are investigated

EXPERIMENTAL

Effect of ZnO

Effect of Basicity

Effect of Al2O3

Crystal Structure Change of SFCA

CONCLUSIONS