Study on Slagging Characteristics of Co-Combustion of Meager Coal and Spent Cathode Carbon Block
The harmless disposal of spent cathode carbon blocks (SCCBs) has become an urgent issue in the primary aluminum industry, and the disposal of SCCBs by co-combustion in pulverized coal boilers is expected to be the most effective treatment method. A muffle furnace at 815 °C was used in this study to...
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MDPI AG
2023-01-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/16/2/736 |
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| author | Jigang Zhang Zijun Liu Xian Li Bin Wang Zhaocai Teng Kuihua Han |
| author_facet | Jigang Zhang Zijun Liu Xian Li Bin Wang Zhaocai Teng Kuihua Han |
| author_sort | Jigang Zhang |
| collection | DOAJ |
| description | The harmless disposal of spent cathode carbon blocks (SCCBs) has become an urgent issue in the primary aluminum industry, and the disposal of SCCBs by co-combustion in pulverized coal boilers is expected to be the most effective treatment method. A muffle furnace at 815 °C was used in this study to perform a co-combustion experiment of meager coal and SCCBs. The ash fusion characteristics (AFTs), microscopic morphology, and minerals composition of co-combustion ash were characterized. The interaction mechanism of different mineral components and the change in AFTs and viscosity-temperature characteristics were investigated using FactSage software. Results show that the change in the ash deformation temperature (DT) is correlated linearly with the SCCB addition ratio, whereas other characteristic temperatures exhibit a nonlinear relationship. The contents of SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, and Na<sub>2</sub>O collectively determine the DT in the ash, and the influence degree from high to low is in the order of SiO<sub>2</sub>, Na<sub>2</sub>O, and Al<sub>2</sub>O<sub>3</sub>. The phase diagram of Na<sub>2</sub>O–Al<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub> is used to accurately predict the changing trend of the melting point of co-combustion ash. The ratio changes between refractory and fusible minerals in the ash, as well as the degree of low-temperature eutectic reaction between sodium- and calcium-containing minerals, are the main factors affecting the melting point of ash. When the blending amount of SCCBs is 5%, mostly complete combustion is achieved, and slagging does not occur easily. The optimal blending ratio of SCCBs is obtained using the co-combustion method from the aspect of AFTs and viscosity-temperature characteristics. This work lays a theoretical foundation for industrial application. |
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| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T12:53:03Z |
| publishDate | 2023-01-01 |
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| record_format | Article |
| series | Energies |
| spelling | doaj.art-93deeffd55854ed891e7d266867988e22023-11-30T22:03:19ZengMDPI AGEnergies1996-10732023-01-0116273610.3390/en16020736Study on Slagging Characteristics of Co-Combustion of Meager Coal and Spent Cathode Carbon BlockJigang Zhang0Zijun Liu1Xian Li2Bin Wang3Zhaocai Teng4Kuihua Han5Shandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology & Equipment, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaShandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology & Equipment, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaShandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology & Equipment, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaShandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology & Equipment, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaShandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology & Equipment, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaShandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology & Equipment, School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaThe harmless disposal of spent cathode carbon blocks (SCCBs) has become an urgent issue in the primary aluminum industry, and the disposal of SCCBs by co-combustion in pulverized coal boilers is expected to be the most effective treatment method. A muffle furnace at 815 °C was used in this study to perform a co-combustion experiment of meager coal and SCCBs. The ash fusion characteristics (AFTs), microscopic morphology, and minerals composition of co-combustion ash were characterized. The interaction mechanism of different mineral components and the change in AFTs and viscosity-temperature characteristics were investigated using FactSage software. Results show that the change in the ash deformation temperature (DT) is correlated linearly with the SCCB addition ratio, whereas other characteristic temperatures exhibit a nonlinear relationship. The contents of SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, and Na<sub>2</sub>O collectively determine the DT in the ash, and the influence degree from high to low is in the order of SiO<sub>2</sub>, Na<sub>2</sub>O, and Al<sub>2</sub>O<sub>3</sub>. The phase diagram of Na<sub>2</sub>O–Al<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub> is used to accurately predict the changing trend of the melting point of co-combustion ash. The ratio changes between refractory and fusible minerals in the ash, as well as the degree of low-temperature eutectic reaction between sodium- and calcium-containing minerals, are the main factors affecting the melting point of ash. When the blending amount of SCCBs is 5%, mostly complete combustion is achieved, and slagging does not occur easily. The optimal blending ratio of SCCBs is obtained using the co-combustion method from the aspect of AFTs and viscosity-temperature characteristics. This work lays a theoretical foundation for industrial application.https://www.mdpi.com/1996-1073/16/2/736meager coalspent cathode carbon blockco-combustionash fusion characteristicsFactSage |
| spellingShingle | Jigang Zhang Zijun Liu Xian Li Bin Wang Zhaocai Teng Kuihua Han Study on Slagging Characteristics of Co-Combustion of Meager Coal and Spent Cathode Carbon Block Energies meager coal spent cathode carbon block co-combustion ash fusion characteristics FactSage |
| title | Study on Slagging Characteristics of Co-Combustion of Meager Coal and Spent Cathode Carbon Block |
| title_full | Study on Slagging Characteristics of Co-Combustion of Meager Coal and Spent Cathode Carbon Block |
| title_fullStr | Study on Slagging Characteristics of Co-Combustion of Meager Coal and Spent Cathode Carbon Block |
| title_full_unstemmed | Study on Slagging Characteristics of Co-Combustion of Meager Coal and Spent Cathode Carbon Block |
| title_short | Study on Slagging Characteristics of Co-Combustion of Meager Coal and Spent Cathode Carbon Block |
| title_sort | study on slagging characteristics of co combustion of meager coal and spent cathode carbon block |
| topic | meager coal spent cathode carbon block co-combustion ash fusion characteristics FactSage |
| url | https://www.mdpi.com/1996-1073/16/2/736 |
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