Title

EXPERIMENTAL INVEATIGATION OF DIRECT REDUCTION OF HEMATITE-BIOMASS CHAR POWDER COMPOSITE

EXPERIMENTAL INVEATIGATION OF DIRECT REDUCTION OF HEMATITE-BIOMASS CHAR POWDER COMPOSITE

Authorship

Zuo, Haibin; Zhang, Jianliang; Hu., Zhengwen

Zuo, Haibin

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Zhang, Jianliang

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Hu., Zhengwen

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DOI

10.5151/2594-357X-22271

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Abstract

Pulverized biomass char was prepared and mixed with hematite fines with different carbon and oxygen molar ratio (C/O=1.00, 1.15 and 1.30). The blends were heated upto 1,200°C and analized by a thermal gravimetric analyzer and SEM-EDS. The process and mechanism of hematite reduced by biomass char were investigated and compared with that by pulverized coal and coke. The results show that biomass char had a high reactivity, and for the hematite-biomass char blend of C/O=1.15, iron oxides had been reduced completely. The increase of C/O would lead to an enhancement of reaction rate and reduction fraction, but would not change the temperature and trend of each reaction. Compared with pulverized coal and coke, the reaction temperature of hematite reduced by biomass char was at least 100°C lower, the maximum reaction rate was 1.57 times as high as that of coal, and the final reaction fraction was higher than that of coal and coke by more than 13%. Model calculation indicated that, the use of burden composed of biomass char and iron ore for blast furnace will probably decrease the thermal reserve zone temperature, reducing CO equilibrium concentration. For every 2.5% decrease of CO equilibrium concentration ranging from 60% to 70%, the fuel ratios saved were respectively 12.20 kg/t., 11.53 kg/t., 10.91 kg/t. and 10.30kg/t.

Pulverized biomass char was prepared and mixed with hematite fines with different carbon and oxygen molar ratio (C/O=1.00, 1.15 and 1.30). The blends were heated upto 1,200°C and analized by a thermal gravimetric analyzer and SEM-EDS. The process and mechanism of hematite reduced by biomass char were investigated and compared with that by pulverized coal and coke. The results show that biomass char had a high reactivity, and for the hematite-biomass char blend of C/O=1.15, iron oxides had been reduced completely. The increase of C/O would lead to an enhancement of reaction rate and reduction fraction, but would not change the temperature and trend of each reaction. Compared with pulverized coal and coke, the reaction temperature of hematite reduced by biomass char was at least 100°C lower, the maximum reaction rate was 1.57 times as high as that of coal, and the final reaction fraction was higher than that of coal and coke by more than 13%. Model calculation indicated that, the use of burden composed of biomass char and iron ore for blast furnace will probably decrease the thermal reserve zone temperature, reducing CO equilibrium concentration. For every 2.5% decrease of CO equilibrium concentration ranging from 60% to 70%, the fuel ratios saved were respectively 12.20 kg/t., 11.53 kg/t., 10.91 kg/t. and 10.30kg/t.

Keywords

Ironmaking; Biomass char; Hematite; Reduction.

Ironmaking; Biomass char; Hematite; Reduction.