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

Abstract

Research Group on Porous Meso-mosaic Texture Sinter in ISIJ was established from 2001 to 2004 fiscal years to overcome difficulties to use the great amount of goethite in sintering and at the same time to improve the sinter quality. Especially, since the beginning of the present research project the ratio of Marra Mamba goethitic ore was considered to increase rapidly, and the amount of sinter necessary for the Japanese integrated steel industries was thought hard to be produced satisfactorily, because Marra Mamba ore having high combined water content and high porosity was expected unsuitable for sintering. Therefore, the method of using goethite had been studied and the combination with low slag ratio important for melting behavior of goethite was investigated.Each university had been engaged in basic research such as granulation, agglomeration, evaluation of reaction in a blast furnace to propose a new process for "porous meso-mosaic texture sinter" which was anticipated simultaneously to realize high strength and high reducibility under the conditions of low slag and high goethite ratio in sintering.By combining these basic researches, the theory of agglomeration and the engineering foundation for raw material/sintering/blast furnace process were discussed and a new process for "porous meso-mosaic texture sinter" based on improving granulation process of raw material was searched. As a result, proposed was the MEBIOS (Mosaic Embedding Iron Ore Sintering) method which involved arranging dense pre-granulated pellets (firing cured bed) in a sinter induction bed with a raw material composition capable of forming a suitable void network under normal sintering conditions.

Effect of Micro-particles in Iron Ore on the Granule Growth and Strength

“…Recently in the research project on "Sintering through Designing of Composite Granulation & Bed Structure" undertaken by a group led by Kasai, MEBIOS (mosaic embedding iron ore sintering) [7][8][9] is under study. The main objectives of the MEBIOS sintering method are to find measures for the effective utilization of Marramamba iron ore and measures to improve sinter productivity, and by embedding pellets made mainly of Marramamba iron ore, ventilation routes are effectively formed in the sintering structure, improving the productivity of sinter.…”

Effects of Alumina on Sintering Performance of Hematite Iron Ores

“…It is believed that the strength, reducibility and size distribution of sinter particles and the yield from a sinter strand are determined by the inherent strength of the bonding phases present and the structure of the pores. 22,23) Furthermore, different pore sizes seem to have different effects on sinter strength, reducibility and other properties: the high temperature reducing property is controlled by the micro-pore sinter structure, while the sinter strength is determined by the macro-pore sinter structure. 22,23) It is therefore important to optimise the pore structure in sinter to improve its reducibility, while maintaining the cold strength, reduction degradation and load softening properties.…”

“…22,23) Furthermore, different pore sizes seem to have different effects on sinter strength, reducibility and other properties: the high temperature reducing property is controlled by the micro-pore sinter structure, while the sinter strength is determined by the macro-pore sinter structure. 22,23) It is therefore important to optimise the pore structure in sinter to improve its reducibility, while maintaining the cold strength, reduction degradation and load softening properties.The physicochemical properties of the primary melt become increasingly important as the amount of slag in sinter decreases. Loo and Leung discussed the effect of the physicochemical properties of the primary melt on the reshaping and coalescing process of the primary melt and bubbles formed in the flame front during sintering and therefore on the resulting pore structure of the sinter.…”

Preparation of BF Burden from Titanomagnetite Concentrate by Composite Agglomeration Process (CAP)

“…[18][19][20] Similar process named mosaic embedding iron ore sintering (MEBIOS) displays its predominance on efficiently using low-grade iron ores and limonite, ensuring high productivity and reducibility and enhancing sinter strength. [21][22][23] Our previous study 24) showed that acidic sinter (basicity < 0.5) made from titanomagntite concentrate mainly solidifies in the form of titanohematite and titanomagnetite and very few perovskite was generated in this sinter. Ultra-high basicity (basicity > 2.5) facilitated the formation of SFCA in sinter, which can offset the adverse effect of perovskite to sinter strength due to its excellent bonding strength.…”