The effect of additives (CaO, Na2CO3, Na2SO4) on the preparation of reduced iron powder from iron concentrate containing 70.25% Fe and 1.86% SiO2 was investigated. The thermodynamics calculation of the reactions between additives and ferrous silicate (Fe2SiO4) was analyzed. The optimum additive is CaO deduced from the thermodynamic analysis for the beginning temperature of reaction is the lowest of 650 K. Then the effects of additives on the preparation of reduced iron powder were investigated by the experiment: two-step carbon-hydrogen reduction of iron concentrate at 1423 K. The results indicated that adding Na2CO3 increased the T. Fe content of the reduced iron powder to 98.32%. Adding CaO dropped the T. Fe content to 93.27%, and the SiO2 content was declined to 1.65%. The additive (CaO) can inhibit the formation of Fe2SiO4, but a new phase (3CaO?SiO2) which was composite of Ca and Si was wrapped in metallic iron. The wrapped structure contributed to the hard removal of Si.
Yuxin CAO Henghui WANG Jianghua MA Dong ZHAO Guangqiang LI
. The Effect of Additives on the Preparation of Reduced Iron Powder from Iron Concentrate[J]. The Chinese Journal of Process Engineering, 2018
, 18(1)
: 133
-139
.
DOI: 10.12034/j.issn.1009-606X.217190
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