Experimental Evaluation of Chemical Composition and Viscosity of Melts during Iron Ore Sintering

Abstract

The viscosity of the melts formed in the sintering reaction was measured for evaluating the fluidity of the melts, which play a crucial role in the sintering process. Using the sphere draw-up method carried out the measurements of high temperature viscosity. With low-melting point compositions of the Fe 2 O 3 -CaO-SiO 2 system, the viscosity of high SiO 2 content melts (Fe 2 O 3 /CaO/SiO 2 ϭ38.5/34.5/27.0 weight basis) was 5 times higher than that of low SiO 2 content melts (Fe 2 O 3 /CaOϭ80/20). The viscosity of low SiO 2 content increased with addition of Al 2 O 3 and SiO 2 . Similarly, with melt compositions generated from actual ores, viscosity depended on the contents of Al 2 O 3 and SiO 2 .Based on the results, the viscosity of the melted liquid was estimated from the chemical composition, and the viscosity of the solid-liquid coexistence phase was also evaluated using a viscosity calculating equation for suspensions. The viscosity distribution of the solid-liquid coexistence phase at 1 300°C in the ternary composition system Fe 2 O 3 -CaO-SiO 2 was obtained.

Viscosity Measurement of Calcium Ferrite Based Slags during Structural Relaxation Process

“…In contrast, Fe 3ϩ (4) decreased with the increase in fraction of Fe 3ϩ (6) with the melting time. The coordination structure of Fe 3ϩ was equilibrated after 120 min.…”

“…Figure 1 represents the temperature dependences of the viscosity for CaO-Fe 2 O 3 melts (CaO content: 18.9-20 wt%, Fe 2 O 3 content: 80-81.1 wt%) reported by several researchers. [6][7][8] As shown in the figure, the tempera- ) and the coordination number of Fe 3ϩ . Viscosity of the CF based slags decreased with the melting time at all the temperature (1 673 K, 1 773 K or 1 873 K).…”

“…[6][7][8] melting time dependence on the viscosity, which would have academic interests. The aim of the present study is to clarify the melting time dependences of the viscosity for CF based slag as a first step of the physical property study for the liquids generated during the process of iron ores sintering.…”

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

“…According to literature, 4,19,20) CaO/SiO 2 greater than 1.8 in the sinter feed promotes formation of calcium ferrite which is beneficial for sinter strength. In order to separate the effect of particle size and composition on the melt properties, the dry final feed, with composition shown in Table 3, was screened to various size fractions, and the CaO/SiO 2 ratio was measured for each batch.…”

Summarized Achievements of the Porous Meso-mosaic Texture Sinter Research Project

“…To overcome this problem, a suitable quantitative design should be conducted into the structural formation of sinter cake and the assimilation behavior of sinter melting based on a thorough understanding of the melt viscosity (solid phase ratio) 14) and a thorough understanding of the melting assimilation of limonite ore.…”