Behavior of Liquid Phase Formation during Iron Ores Sintering

Abstract

The improvement of industrial parameters like the basicity and sintering temperature and the selection of raw materials to form the acicular calcium ferrites become the hot topic in sintering production. However, the experimental with the sintering pot in the laboratory is still a main method up to now, no effective mathematical model or experience equations were developed. Factsage is a software for thermodynamic calculation in ironmaking and steelmaking. In present study, Factsage was used to calculate the liquid phases formulation during the sintering. The effect of the chemical compositions on the liquidus projection was also discussed. It was found that the content of liquid phase formed is about 25%-70% at 1 250°C due to their chemical composition. The more SiO2, the easier to form liquid phase. The experiments were carried out for the validation. It was found that the calculations of the mass of liquid phase generation cannot give a very good and accurate agreement with the measurement of the melting behavior of the sample quantificationally, however, for the ability of the liquid phase formation during the sintering, the calculations can give a good qualitative results, especially in the temperature of melting begin and the temperature of 50% shrinkage. The calculations reported in this study can be used to estimate the sintering behavior of the iron ores under a certain industrial condition to reduce the extra experiments. The experiments also shows that the calculations by Factsage can give some good explanations on the phenomenon of the melting behavior of different samples.

Formation of Nitrogen Mono Oxide (NO) during Iron Ore Sintering Process

“…Sintering materials mainly compose of iron ores, fluxes and fuels, the chemical compositions are mainly Fe 2 O 3 , Fe 3 O 4 , CaO and C. Moreover, series compounds are generated by high temperature process, such as calcium ferrite like CaO·Fe 2 O 3 , 2CaO·Fe 2 O 3 , and CaO·2Fe 2 O 3 as well as silicate com-pounds like CaO·FeO·SiO 2 and 2FeO·SiO 2 . [20][21][22] When the basicity increases to 2.0 and above, calcium ferrite is the main binder phase.…”

Effect of Coarse-grain and Low-grade Iron Ores on Sinter Properties

“…13,15) Other components have shown different effects. 26) In the current study, the phase diagrams of Fe 2 O 3 -CaOSiO 2 system corresponding to the compositions of the three coarse-grain and low-grade ores were produced using FactSage™ 7.0, and the effect of ore gangue content on liquid phase at a temperature of 1 200-1 350°C was investigated.…”

“…6,12,13) It is therefore important to maintain an optimum size distribution and sinter mix composition for a balance of strong bonding and appropriate sinter permeability. [14][15][16] In this paper, the relationship between the gangue content and amount and fluidity of liquid phase formed during sintering of three coarse-grained, low-grade ores is discussed.…”

Understanding Coalescence in Iron Ore Sintering Using Two Bench-scale Techniques

“…There appears to be only one paper in the open literature on the use of FactSage on iron ore sintering melts. 15) This means that there is need for caution when FactSage results are used to analyse experimental data on sinter melts.…”

“…Costa et al 13) employed the same technique to determine the melting temperature of a sinter mix and a temperature based on 2/3 reduction in pyramid height was used. In place of pyramids, cylinders have also been used and their heights determined as functions of temperature by Chu et al 14) and Lv et al 15) A Carbolite Coal Ash Fusion Furnace-Digital was used in this study. The furnace has a horizontal working tube with internal diameter of 79 mm and capability of a maximum temperature of 1 600°C.…”