Title

Effect of oxides addition on the reduction of hematite and graphite mixture obtained by the mechanical milling.

Effect of oxides addition on the reduction of hematite and graphite mixture obtained by the mechanical milling.

Authorship

KASHIWAYA, YOSHIAKI; SUZUKI, RYOUSUKE; ISHII, KUNIYOSHI

KASHIWAYA, YOSHIAKI

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SUZUKI, RYOUSUKE

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ISHII, KUNIYOSHI

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DOI

10.5151/2594-357x-34Red-541-550

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Abstract

3mass%CaCO₃, SiO₂ and Al₂O₃ were added to hematite-graphite mixture respectively and the milling was carried out for 24h. To clarify the effect on the reaction rate, TG-DTA analysis was carried out under a heating up condition (10°C/min, 30min hold at 1100°C) and an argon atmosphere. 3%CaCO₃ addition increased the reactivity of hematite-graphite milling sample at 24h. The effect of activation corresponded to the 72h milling of hematite-graphite mixture. Inversely, 3%SiO₂ addition decreased the reactivity and the effect corresponded to the 6h, even though the milling was carried out for 24h. 3%Al₂O₃ addition showed no effect on the reaction. It was found that the gas evolution during milling was not CO₂, but CO. Taking into account the result of XRD, the reaction occurring during milling of CaCO₃ was as follows: CaCO₃ = CaO₂ + CO. It was considered that the product of CaCO₃ milling was the mixture of CaCO₃ and CaO₂

3mass%CaCO₃, SiO₂ and Al₂O₃ were added to hematite-graphite mixture respectively and the milling was carried out for 24h. To clarify the effect on the reaction rate, TG-DTA analysis was carried out under a heating up condition (10°C/min, 30min hold at 1100°C) and an argon atmosphere. 3%CaCO₃ addition increased the reactivity of hematite-graphite milling sample at 24h. The effect of activation corresponded to the 72h milling of hematite-graphite mixture. Inversely, 3%SiO₂ addition decreased the reactivity and the effect corresponded to the 6h, even though the milling was carried out for 24h. 3%Al₂O₃ addition showed no effect on the reaction. It was found that the gas evolution during milling was not CO₂, but CO. Taking into account the result of XRD, the reaction occurring during milling of CaCO₃ was as follows: CaCO₃ = CaO₂ + CO. It was considered that the product of CaCO₃ milling was the mixture of CaCO₃ and CaO₂

Keywords

Milling of hematite and graphite, effect of oxides addition, CaCO₃, SiO₂, Al₂O₃, reduction reaction by solid carbon.

Milling of hematite and graphite, effect of oxides addition, CaCO₃, SiO₂, Al₂O₃, reduction reaction by solid carbon.