Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing Slag
The unstable substances in steel slag are the main substances that affect its stability, which limits the large-scale resource utilization of steel slag. Most of the current methods for stabilizing electric arc furnace (EAF) slag are time-consuming and cannot be completely stabilized. In view of thi...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-09-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/13/18/10435 |
| _version_ | 1827727305791766528 |
|---|---|
| author | How-Ji Chen You-Ren Lin Chao-Wei Tang Yi-Chun Hung |
| author_facet | How-Ji Chen You-Ren Lin Chao-Wei Tang Yi-Chun Hung |
| author_sort | How-Ji Chen |
| collection | DOAJ |
| description | The unstable substances in steel slag are the main substances that affect its stability, which limits the large-scale resource utilization of steel slag. Most of the current methods for stabilizing electric arc furnace (EAF) slag are time-consuming and cannot be completely stabilized. In view of this, this study aimed to explore the feasibility of microbial-induced calcium carbonate precipitation (MICP) technology for stabilizing EAF reducing slag, and this was to be achieved by using the reaction between carbonate ions and free calcium oxide (f-CaO) in reducing slag to form a more stable calcium carbonate to achieve the purpose of stabilization. The test results showed that, when the EAF reducing slag aggregates (ERSAs) were immersed in a <i>Sporosarcina pasteurii</i> bacteria solution or water, the f-CaO contained in it would react such that stabilization was achieved. The titration test results showed that the f-CaO content of the ERSAs immersed in the bacterial solution and water decreased. The expansion test results of the ERSAs that were subjected to hydration showed that the seven-day expansion of ERSAs after biomineralization could meet the Taiwan regulation requirement of an expansion rate less than 0.5%. The thermogravimetric analysis showed that both the experimental group and the control group might contain calcium carbonate compounds. The results of the X-ray diffraction analysis showed that the CaCO<sub>3</sub> content in the ERSAs that were immersed in the bacterial solution was significantly higher than those that were immersed in water. Moreover, the compressive strength test results of concrete prepared with ERSAs showed that the compressive strength of the control group concrete began to decline after 28 days. In contrast, the experimental group concrete had a good stabilization effect, and there was no decline in compressive strength until 180 days. At 240 days, the surface cracks of the experimental group were particularly small, while the surface of the control group showed obvious cracks. These results confirmed that a mineralization reaction with <i>S. pasteurii</i> bacteria could be used as a stabilization technology for ERSAs. |
| first_indexed | 2024-03-10T23:04:26Z |
| format | Article |
| id | doaj.art-7b2413b733ef48c99672f8c2197eea52 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T23:04:26Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-7b2413b733ef48c99672f8c2197eea522023-11-19T09:27:43ZengMDPI AGApplied Sciences2076-34172023-09-0113181043510.3390/app131810435Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing SlagHow-Ji Chen0You-Ren Lin1Chao-Wei Tang2Yi-Chun Hung3Department of Civil Engineering, National Chung-Hsing University, 145 Xingda Road, South District, Taichung City 40227, TaiwanDepartment of Civil Engineering, National Chung-Hsing University, 145 Xingda Road, South District, Taichung City 40227, TaiwanDepartment of Civil Engineering and Geomatics, Cheng Shiu University, No. 840, Chengching Road, Niaosong District, Kaohsiung 83347, TaiwanDepartment of Civil Engineering, National Chung-Hsing University, 145 Xingda Road, South District, Taichung City 40227, TaiwanThe unstable substances in steel slag are the main substances that affect its stability, which limits the large-scale resource utilization of steel slag. Most of the current methods for stabilizing electric arc furnace (EAF) slag are time-consuming and cannot be completely stabilized. In view of this, this study aimed to explore the feasibility of microbial-induced calcium carbonate precipitation (MICP) technology for stabilizing EAF reducing slag, and this was to be achieved by using the reaction between carbonate ions and free calcium oxide (f-CaO) in reducing slag to form a more stable calcium carbonate to achieve the purpose of stabilization. The test results showed that, when the EAF reducing slag aggregates (ERSAs) were immersed in a <i>Sporosarcina pasteurii</i> bacteria solution or water, the f-CaO contained in it would react such that stabilization was achieved. The titration test results showed that the f-CaO content of the ERSAs immersed in the bacterial solution and water decreased. The expansion test results of the ERSAs that were subjected to hydration showed that the seven-day expansion of ERSAs after biomineralization could meet the Taiwan regulation requirement of an expansion rate less than 0.5%. The thermogravimetric analysis showed that both the experimental group and the control group might contain calcium carbonate compounds. The results of the X-ray diffraction analysis showed that the CaCO<sub>3</sub> content in the ERSAs that were immersed in the bacterial solution was significantly higher than those that were immersed in water. Moreover, the compressive strength test results of concrete prepared with ERSAs showed that the compressive strength of the control group concrete began to decline after 28 days. In contrast, the experimental group concrete had a good stabilization effect, and there was no decline in compressive strength until 180 days. At 240 days, the surface cracks of the experimental group were particularly small, while the surface of the control group showed obvious cracks. These results confirmed that a mineralization reaction with <i>S. pasteurii</i> bacteria could be used as a stabilization technology for ERSAs.https://www.mdpi.com/2076-3417/13/18/10435biomineralizationmicrobial-induced calcium carbonate precipitationreducing slagstabilizationfree calcium oxidecalcium carbonate |
| spellingShingle | How-Ji Chen You-Ren Lin Chao-Wei Tang Yi-Chun Hung Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing Slag Applied Sciences biomineralization microbial-induced calcium carbonate precipitation reducing slag stabilization free calcium oxide calcium carbonate |
| title | Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing Slag |
| title_full | Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing Slag |
| title_fullStr | Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing Slag |
| title_full_unstemmed | Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing Slag |
| title_short | Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing Slag |
| title_sort | application of biomineralization technology in the stabilization of electric arc furnace reducing slag |
| topic | biomineralization microbial-induced calcium carbonate precipitation reducing slag stabilization free calcium oxide calcium carbonate |
| url | https://www.mdpi.com/2076-3417/13/18/10435 |
| work_keys_str_mv | AT howjichen applicationofbiomineralizationtechnologyinthestabilizationofelectricarcfurnacereducingslag AT yourenlin applicationofbiomineralizationtechnologyinthestabilizationofelectricarcfurnacereducingslag AT chaoweitang applicationofbiomineralizationtechnologyinthestabilizationofelectricarcfurnacereducingslag AT yichunhung applicationofbiomineralizationtechnologyinthestabilizationofelectricarcfurnacereducingslag |