# The Effects of Different Zn Forms on Sintering Basic Characteristics of Iron Ore

## TL;DR

This study examines how different forms of zinc affect the sintering properties of iron ore, impacting factors like temperature and strength.

## Contribution

The paper introduces new insights into how ZnO, ZnFe2O4, and ZnS influence sintering characteristics and SFCA formation in iron ore.

## Key findings

- ZnO and ZnFe2O4 increase the lowest assimilation temperature but decrease liquid phase fluidity in iron ore.
- ZnS accelerates Fe2O3 decomposition but limits SFCA formation due to high decomposition temperatures.
- Zn reduces SFCA microhardness and bonding phase content, lowering sinter compressive strength.

## Abstract

The micro-sintering method was used to determine the sintering basic characteristics of iron ore with Zn contents from 0 to 4%, the influence mechanism of Zn on sintering basic characteristics of iron ore was clarified by means of thermodynamic analysis and first-principles calculations. The results showed that (1) increasing the ZnO and ZnFe2O4 content increased the lowest assimilation temperature (LAT) but decreased the index of liquid phase fluidity (ILF) of iron ore. The addition of ZnS had no obvious effect on LAT but increased the LIF of iron ore. (2) ZnO and ZnFe2O4 reacted with Fe2O3 and CaO, respectively, during sintering, which inhibited the formation of silico-ferrite of calcium and aluminum (SFCA). The addition of ZnS accelerated the decomposition of Fe2O3 in the N2 atmosphere; however, the high decomposition temperature limited the oxidation of ZnS, so the presence of ZnS had a slight inhibitory effect on the formation of SFCA. (3) The Zn concentrated in hematite or silicate and less distributed in SFCA and magnetite in the form of solid solution; meanwhile, the microhardness of the mineral phase decreased with the increase in Zn-containing solid solution content. As the adsorption of Zn on the SFCA crystal surface was more stable, the microhardness of SFCA decreased more. The decrease in microhardness and content of the SFCA bonding phase resulted in a decrease in the compressive strength of the sinter.