4成分系カルシウムフェライト組成の外殻粉層を有するミニペレットを原料とした焼結鉱の品質

抄録

A wide range of sintering experiments were carried out in order to use a large quantity of fine iron ore for the sintering process and to improve the properties of product sinter. Modeled mini-pellets (named duplex pellets) which consisted of coarse iron ore particles as cores and fine mixture, of which chemical composition was specified to a quaternary (CaO-SiO₂-Al₂O₃-Fe₂O₃) calcium ferrite, as shell layer were used in the present experiments.
The effect of ratio of shell in pellet and of iron ore characteristics on the sintering process and metallurgical properties of the product sinter were examined. The results obtained are as follows ;
1)The maximum bed temperature decreased with increasing ratio of shell in pellet from 50 to 80 mass%, however, the permeability of the sintering bed was not significantly affected.
2)Reduction degradation property of product sinter was able to be improved with increasing ratio of shell in pellet as the strength and reducibility of product sinter were kept in high values. These were due to both that the matrix was changed from glassy silicate to acicular calcium ferrite and that the amount of matrix was increased.
3) When the ratio of shell in pellet was 80 mass%, reduction degradation property of product sinter was improved by the use of fine iron ore with good reactivity with limestone, although strength and reducibility of product sinter were not significantly affected.