Effects of Different CaO/Al<sub>2</sub>O<sub>3</sub> Ratios on the Phase Composition and Desulfurization Ability of CaO-Based Desulfurizers in Hot Metal
In response to the development of low-carbon smelting technology, reducing the use of fluor-containing materials in desulfurizers is an important research topic. The development of new-generation KR (Kambara Reactor) desulfurizers is shifting towards a higher Al<sub>2</sub>O<sub>3&...
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MDPI AG
2024-03-01
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| Online Access: | https://www.mdpi.com/2075-4701/14/3/363 |
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| author | Jyun-Ming Shen Chi-Ming Lin Yu-En Chang Hui-Jan Lin Weite Wu |
| author_facet | Jyun-Ming Shen Chi-Ming Lin Yu-En Chang Hui-Jan Lin Weite Wu |
| author_sort | Jyun-Ming Shen |
| collection | DOAJ |
| description | In response to the development of low-carbon smelting technology, reducing the use of fluor-containing materials in desulfurizers is an important research topic. The development of new-generation KR (Kambara Reactor) desulfurizers is shifting towards a higher Al<sub>2</sub>O<sub>3</sub> content rather than CaF<sub>2</sub>, yet there is currently an absence of thorough and comprehensive mechanisms for desulfurization. Consequently, this research provides an extensive comparison using a specially constructed small-scale KR desulfurization hot model test, alongside FactSage simulation and SEM analysis (of desulfurization process). The findings indicate that at 1400 °C, for the desulfurization of molten iron, the capacity for desulfurization initially increases and then diminishes as the Al<sub>2</sub>O<sub>3</sub> content in the KR desulfurizer rises. With Al<sub>2</sub>O<sub>3</sub> content in the desulfurizer below 22 wt.%, the phase composition predominantly consists of C<sub>3</sub>A, employing a solid<sub>(slag)</sub>–liquid<sub>(metal)</sub> diffusion method for desulfurization. The optimal desulfurization capacity (Ls: 64.1) is observed when the Al<sub>2</sub>O<sub>3</sub> content is 15 wt.%, attributed to the simultaneous presence of CaO particle precipitation and C<sub>3</sub>A. However, as the Al<sub>2</sub>O<sub>3</sub> content reaches 20 wt.%, all the oversaturated CaO integrates into C<sub>3</sub>A, leading to a reduction in Ls from 64.1 to 10.7, thereby diminishing the desulfurization capacity by approximately sixfold. When Al<sub>2</sub>O<sub>3</sub> exceeds 22 wt.%, the phase composition transitions from the C<sub>3</sub>A to C<sub>12</sub>A<sub>7</sub> phase, and the desulfurization approach shifts from solid<sub>(slag)</sub>–liquid<sub>(metal)</sub> to liquid<sub>(slag)</sub>–liquid<sub>(metal)</sub> diffusion, with Ls decreasing to 23.4. This reduction is due to C<sub>12</sub>A<sub>7</sub>’s lower sulfur capacity compared to C<sub>3</sub>A and the absence of saturated CaO particle precipitation. Therefore, for Al<sub>2</sub>O<sub>3</sub> to effectively replace fluorite in KR desulfurizers, a higher presence of C<sub>3</sub>A phases and CaO particle precipitation are essential. The desulfurizer must contain over 65 wt.% CaO and maintain A<sub>l2</sub>O<sub>3</sub> levels at 10~16.2 wt.%. |
| first_indexed | 2024-04-24T18:00:49Z |
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| language | English |
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| spelling | doaj.art-c5de40cb40fb4ae5a84388144d0408d12024-03-27T13:54:34ZengMDPI AGMetals2075-47012024-03-0114336310.3390/met14030363Effects of Different CaO/Al<sub>2</sub>O<sub>3</sub> Ratios on the Phase Composition and Desulfurization Ability of CaO-Based Desulfurizers in Hot MetalJyun-Ming Shen0Chi-Ming Lin1Yu-En Chang2Hui-Jan Lin3Weite Wu4Department of Materials Science and Engineering, National Chung Hsing University, Taichung City 402202, TaiwanAcademy of Circular Economy, National Chung Hsing University, Taichung City 402202, TaiwanDepartment of Materials Science and Engineering, National Chung Hsing University, Taichung City 402202, TaiwanChina Steel Corporation, Kaohsiung City 812010, TaiwanDepartment of Materials Science and Engineering, National Chung Hsing University, Taichung City 402202, TaiwanIn response to the development of low-carbon smelting technology, reducing the use of fluor-containing materials in desulfurizers is an important research topic. The development of new-generation KR (Kambara Reactor) desulfurizers is shifting towards a higher Al<sub>2</sub>O<sub>3</sub> content rather than CaF<sub>2</sub>, yet there is currently an absence of thorough and comprehensive mechanisms for desulfurization. Consequently, this research provides an extensive comparison using a specially constructed small-scale KR desulfurization hot model test, alongside FactSage simulation and SEM analysis (of desulfurization process). The findings indicate that at 1400 °C, for the desulfurization of molten iron, the capacity for desulfurization initially increases and then diminishes as the Al<sub>2</sub>O<sub>3</sub> content in the KR desulfurizer rises. With Al<sub>2</sub>O<sub>3</sub> content in the desulfurizer below 22 wt.%, the phase composition predominantly consists of C<sub>3</sub>A, employing a solid<sub>(slag)</sub>–liquid<sub>(metal)</sub> diffusion method for desulfurization. The optimal desulfurization capacity (Ls: 64.1) is observed when the Al<sub>2</sub>O<sub>3</sub> content is 15 wt.%, attributed to the simultaneous presence of CaO particle precipitation and C<sub>3</sub>A. However, as the Al<sub>2</sub>O<sub>3</sub> content reaches 20 wt.%, all the oversaturated CaO integrates into C<sub>3</sub>A, leading to a reduction in Ls from 64.1 to 10.7, thereby diminishing the desulfurization capacity by approximately sixfold. When Al<sub>2</sub>O<sub>3</sub> exceeds 22 wt.%, the phase composition transitions from the C<sub>3</sub>A to C<sub>12</sub>A<sub>7</sub> phase, and the desulfurization approach shifts from solid<sub>(slag)</sub>–liquid<sub>(metal)</sub> to liquid<sub>(slag)</sub>–liquid<sub>(metal)</sub> diffusion, with Ls decreasing to 23.4. This reduction is due to C<sub>12</sub>A<sub>7</sub>’s lower sulfur capacity compared to C<sub>3</sub>A and the absence of saturated CaO particle precipitation. Therefore, for Al<sub>2</sub>O<sub>3</sub> to effectively replace fluorite in KR desulfurizers, a higher presence of C<sub>3</sub>A phases and CaO particle precipitation are essential. The desulfurizer must contain over 65 wt.% CaO and maintain A<sub>l2</sub>O<sub>3</sub> levels at 10~16.2 wt.%.https://www.mdpi.com/2075-4701/14/3/363hot metal desulfurizationcalcium aluminateKR mechanical stirring |
| spellingShingle | Jyun-Ming Shen Chi-Ming Lin Yu-En Chang Hui-Jan Lin Weite Wu Effects of Different CaO/Al<sub>2</sub>O<sub>3</sub> Ratios on the Phase Composition and Desulfurization Ability of CaO-Based Desulfurizers in Hot Metal Metals hot metal desulfurization calcium aluminate KR mechanical stirring |
| title | Effects of Different CaO/Al<sub>2</sub>O<sub>3</sub> Ratios on the Phase Composition and Desulfurization Ability of CaO-Based Desulfurizers in Hot Metal |
| title_full | Effects of Different CaO/Al<sub>2</sub>O<sub>3</sub> Ratios on the Phase Composition and Desulfurization Ability of CaO-Based Desulfurizers in Hot Metal |
| title_fullStr | Effects of Different CaO/Al<sub>2</sub>O<sub>3</sub> Ratios on the Phase Composition and Desulfurization Ability of CaO-Based Desulfurizers in Hot Metal |
| title_full_unstemmed | Effects of Different CaO/Al<sub>2</sub>O<sub>3</sub> Ratios on the Phase Composition and Desulfurization Ability of CaO-Based Desulfurizers in Hot Metal |
| title_short | Effects of Different CaO/Al<sub>2</sub>O<sub>3</sub> Ratios on the Phase Composition and Desulfurization Ability of CaO-Based Desulfurizers in Hot Metal |
| title_sort | effects of different cao al sub 2 sub o sub 3 sub ratios on the phase composition and desulfurization ability of cao based desulfurizers in hot metal |
| topic | hot metal desulfurization calcium aluminate KR mechanical stirring |
| url | https://www.mdpi.com/2075-4701/14/3/363 |
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