Reduction Behaviors of Silicon–Ferrite from Calcium and Aluminum in a Hydrogen-Rich Blast Furnace
Silicon–ferrite from calcium and aluminum (SFCA) is one of the primary binding phases in sinter. To better investigate the reduction process of SFCA under hydrogen-rich conditions in a blast furnace, isothermal reduction experiments were designed using three different hydrogen volume fractions (6%,...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-11-01
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| Series: | Metals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4701/14/11/1306 |
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| Summary: | Silicon–ferrite from calcium and aluminum (SFCA) is one of the primary binding phases in sinter. To better investigate the reduction process of SFCA under hydrogen-rich conditions in a blast furnace, isothermal reduction experiments were designed using three different hydrogen volume fractions (6%, 10%, and 14%) at temperatures within the blast furnace’s lump zone range (1073 K, 1173 K, and 1273 K). The experimental results revealed that the reduction of SFCA proceeds in two stages: in the first stage, SFCA is initially reduced to Fe<sub>3</sub>O<sub>4</sub>; in the second stage, Fe<sub>3</sub>O<sub>4</sub> is further reduced to FeO, with the equilibrium phases being FeO, Ca<sub>2</sub>Al<sub>2</sub>SiO<sub>7</sub>, and Ca<sub>2</sub>SiO<sub>4</sub>. The fastest reduction rate was observed at 1273 K. When the hydrogen volume fraction was 6% and the temperatures were 1073 K, 1173 K, and 1273 K, the reaction mechanism followed the 3D diffusion model (G-B), with an apparent activation energy of 32.087 kJ·<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>mol</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula> and a pre-exponential factor of 0.1419. In comparison, at hydrogen volume fractions of 10% and 14%, the reaction mechanism shifted to the Shrinking core model (n = 3). The findings of this study can provide guidance for actual production and optimization of blast furnace parameters aimed at achieving low-carbon emissions in the steel-making process. |
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| ISSN: | 2075-4701 |