Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas Desulfurization
In order to upgrade the utilization of flue gas desulfurization (FGD) gypsum, crystal modifier aluminum sulfate (Al2(SO4)3) was added into FGD gypsum to prepare calcined gypsum by calcining at normal pressure, and the effect of Al2(SO4)3 addition on the performance of calcined gypsum was studied. Th...
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| Format: | Article |
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Kaunas University of Technology
2024-02-01
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| Series: | Medžiagotyra |
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| Online Access: | https://matsc.ktu.lt/index.php/MatSc/article/view/34396 |
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| author | Guanji CHENG Jianying HAO Bing GUO Tao HU Shengchang WANG |
| author_facet | Guanji CHENG Jianying HAO Bing GUO Tao HU Shengchang WANG |
| author_sort | Guanji CHENG |
| collection | DOAJ |
| description | In order to upgrade the utilization of flue gas desulfurization (FGD) gypsum, crystal modifier aluminum sulfate (Al2(SO4)3) was added into FGD gypsum to prepare calcined gypsum by calcining at normal pressure, and the effect of Al2(SO4)3 addition on the performance of calcined gypsum was studied. The results show that the addition of Al2(SO4)3 to FGD gypsum is slightly beneficial to promote the crystallization of hemihydrate gypsum (HH) along the a-axis direction. The Al2(SO4)3 addition also has a quick-setting effect on gypsum plaster during the hydration process, meanwhile inhibiting the growth of the (020) crystal plane of dihydrate gypsum (DH), then promoting uniform growth and aggregation along the c-axis. The close stacking makes hardened gypsum body dense and improves the strength of calcined gypsum. The strength of calcined gypsum prepared by calcining FGD gypsum with Al2(SO4)3 of 0.6 wt.% at 170 ℃ for 2 h is the highest. 2 h and 7 d flexural strength are 3.80 MPa and 7.20 MPa, and 2 h and 7 d compressive strength are 9.05 MPa and 19.23 MPa, respectively. In addition, 2 h flexural and compressive strength of the calcined gypsum with 0.6 ~ 1.0 wt.% of Al2(SO4)3 prepared at 170 ~ 180 ℃ for 2 h increase by 16 ~ 22 % and 20 ~ 33 %, respectively, which is very advantageous for the high value-added reuse of FGD gypsum for the preparation of high-quality calcined gypsum. |
| first_indexed | 2024-03-07T23:37:47Z |
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| issn | 1392-1320 2029-7289 |
| language | English |
| last_indexed | 2024-03-07T23:37:47Z |
| publishDate | 2024-02-01 |
| publisher | Kaunas University of Technology |
| record_format | Article |
| series | Medžiagotyra |
| spelling | doaj.art-ba53bf389ee64726abf318499a5929a92024-02-20T05:53:46ZengKaunas University of TechnologyMedžiagotyra1392-13202029-72892024-02-0130110611310.5755/j02.ms.3439639650Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas DesulfurizationGuanji CHENG0Jianying HAO1https://orcid.org/0000-0001-5287-9799Bing GUO2Tao HU3Shengchang WANG4Taiyuan University of Science and TechnologyTaiyuan University of Science and TechnologyTaiyuan University of Science and TechnologyTaiyuan University of Science and TechnologyTaiyuan University of Science and TechnologyIn order to upgrade the utilization of flue gas desulfurization (FGD) gypsum, crystal modifier aluminum sulfate (Al2(SO4)3) was added into FGD gypsum to prepare calcined gypsum by calcining at normal pressure, and the effect of Al2(SO4)3 addition on the performance of calcined gypsum was studied. The results show that the addition of Al2(SO4)3 to FGD gypsum is slightly beneficial to promote the crystallization of hemihydrate gypsum (HH) along the a-axis direction. The Al2(SO4)3 addition also has a quick-setting effect on gypsum plaster during the hydration process, meanwhile inhibiting the growth of the (020) crystal plane of dihydrate gypsum (DH), then promoting uniform growth and aggregation along the c-axis. The close stacking makes hardened gypsum body dense and improves the strength of calcined gypsum. The strength of calcined gypsum prepared by calcining FGD gypsum with Al2(SO4)3 of 0.6 wt.% at 170 ℃ for 2 h is the highest. 2 h and 7 d flexural strength are 3.80 MPa and 7.20 MPa, and 2 h and 7 d compressive strength are 9.05 MPa and 19.23 MPa, respectively. In addition, 2 h flexural and compressive strength of the calcined gypsum with 0.6 ~ 1.0 wt.% of Al2(SO4)3 prepared at 170 ~ 180 ℃ for 2 h increase by 16 ~ 22 % and 20 ~ 33 %, respectively, which is very advantageous for the high value-added reuse of FGD gypsum for the preparation of high-quality calcined gypsum.https://matsc.ktu.lt/index.php/MatSc/article/view/34396fgd gypsumcrystal modifiercalcined gypsumaluminum sulfatestrength |
| spellingShingle | Guanji CHENG Jianying HAO Bing GUO Tao HU Shengchang WANG Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas Desulfurization Medžiagotyra fgd gypsum crystal modifier calcined gypsum aluminum sulfate strength |
| title | Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas Desulfurization |
| title_full | Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas Desulfurization |
| title_fullStr | Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas Desulfurization |
| title_full_unstemmed | Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas Desulfurization |
| title_short | Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas Desulfurization |
| title_sort | effect of al2 so4 3 additive on the properties of calcined gypsum prepared from flue gas desulfurization |
| topic | fgd gypsum crystal modifier calcined gypsum aluminum sulfate strength |
| url | https://matsc.ktu.lt/index.php/MatSc/article/view/34396 |
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