In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage Evolution
The accumulation of original phosphogypsum (OPG) has occupied considerable land resources, which have induced significant environmental problems worldwide. The OPG-based cemented paste backfill (OCPB) has been introduced as a promising solution. In this study, a water-washing pre-treatment was used...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-11-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/14/22/6993 |
| _version_ | 1797509503011258368 |
|---|---|
| author | Yikai Liu Qiusong Chen Yunmin Wang Qinli Zhang Hongpeng Li Chaoyu Jiang Chongchong Qi |
| author_facet | Yikai Liu Qiusong Chen Yunmin Wang Qinli Zhang Hongpeng Li Chaoyu Jiang Chongchong Qi |
| author_sort | Yikai Liu |
| collection | DOAJ |
| description | The accumulation of original phosphogypsum (OPG) has occupied considerable land resources, which have induced significant environmental problems worldwide. The OPG-based cemented paste backfill (OCPB) has been introduced as a promising solution. In this study, a water-washing pre-treatment was used to purify OPG, aiming to optimize the transport performance and mechanical properties of backfills. The overall results proved that in treated phosphogypsum-based cemented paste backfill (TCPB), the altered particle size distribution can alleviate the shear-thinning characteristic. The mechanical properties were significantly optimized, of which a maximum increase of 183% of stress value was observed. With more pronounced AE signals, the TCPB samples demonstrated better residual structures after the ultimate strength values but with more unstable cracks with high amplitude generated during loading. Principal component analysis confirmed the adverse effects of fluorine and phosphorus on the damage fractal dimensions. The most voluminous hydration products observed were amorphous CSH and ettringite. The interlocked stellate clusters may be associated with the residual structure and the after-peak AE events evident in TCPB, indicate that more significant stress should be applied to break the closely interlocked stitches. Ultimately, the essential findings in this experimental work can provide a scientific reference for efficient OPG recycling. |
| first_indexed | 2024-03-10T05:18:41Z |
| format | Article |
| id | doaj.art-534992349b914bf4bbf93e320ba43755 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T05:18:41Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-534992349b914bf4bbf93e320ba437552023-11-23T00:12:04ZengMDPI AGMaterials1996-19442021-11-011422699310.3390/ma14226993In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage EvolutionYikai Liu0Qiusong Chen1Yunmin Wang2Qinli Zhang3Hongpeng Li4Chaoyu Jiang5Chongchong Qi6Department of Geosciences, University of Padova, 35131 Padova, ItalySinosteel Maanshan General Institute of Mining Research Co., Ltd., Maanshan 243000, ChinaSinosteel Maanshan General Institute of Mining Research Co., Ltd., Maanshan 243000, ChinaSchool of Resources and Safety Engineering, Central South University, Changsha 410083, ChinaYinshan Mining Co., Ltd., Jiangxi Copper Group, Dexing 334200, ChinaSchool of Resources and Safety Engineering, Central South University, Changsha 410083, ChinaSchool of Resources and Safety Engineering, Central South University, Changsha 410083, ChinaThe accumulation of original phosphogypsum (OPG) has occupied considerable land resources, which have induced significant environmental problems worldwide. The OPG-based cemented paste backfill (OCPB) has been introduced as a promising solution. In this study, a water-washing pre-treatment was used to purify OPG, aiming to optimize the transport performance and mechanical properties of backfills. The overall results proved that in treated phosphogypsum-based cemented paste backfill (TCPB), the altered particle size distribution can alleviate the shear-thinning characteristic. The mechanical properties were significantly optimized, of which a maximum increase of 183% of stress value was observed. With more pronounced AE signals, the TCPB samples demonstrated better residual structures after the ultimate strength values but with more unstable cracks with high amplitude generated during loading. Principal component analysis confirmed the adverse effects of fluorine and phosphorus on the damage fractal dimensions. The most voluminous hydration products observed were amorphous CSH and ettringite. The interlocked stellate clusters may be associated with the residual structure and the after-peak AE events evident in TCPB, indicate that more significant stress should be applied to break the closely interlocked stitches. Ultimately, the essential findings in this experimental work can provide a scientific reference for efficient OPG recycling.https://www.mdpi.com/1996-1944/14/22/6993cemented paste backfillwaste recyclephosphogypsumunconfined compressive strengthmechanical properties |
| spellingShingle | Yikai Liu Qiusong Chen Yunmin Wang Qinli Zhang Hongpeng Li Chaoyu Jiang Chongchong Qi In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage Evolution Materials cemented paste backfill waste recycle phosphogypsum unconfined compressive strength mechanical properties |
| title | In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage Evolution |
| title_full | In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage Evolution |
| title_fullStr | In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage Evolution |
| title_full_unstemmed | In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage Evolution |
| title_short | In Situ Remediation of Phosphogypsum with Water-Washing Pre-Treatment Using Cemented Paste Backfill: Rheology Behavior and Damage Evolution |
| title_sort | in situ remediation of phosphogypsum with water washing pre treatment using cemented paste backfill rheology behavior and damage evolution |
| topic | cemented paste backfill waste recycle phosphogypsum unconfined compressive strength mechanical properties |
| url | https://www.mdpi.com/1996-1944/14/22/6993 |
| work_keys_str_mv | AT yikailiu insituremediationofphosphogypsumwithwaterwashingpretreatmentusingcementedpastebackfillrheologybehavioranddamageevolution AT qiusongchen insituremediationofphosphogypsumwithwaterwashingpretreatmentusingcementedpastebackfillrheologybehavioranddamageevolution AT yunminwang insituremediationofphosphogypsumwithwaterwashingpretreatmentusingcementedpastebackfillrheologybehavioranddamageevolution AT qinlizhang insituremediationofphosphogypsumwithwaterwashingpretreatmentusingcementedpastebackfillrheologybehavioranddamageevolution AT hongpengli insituremediationofphosphogypsumwithwaterwashingpretreatmentusingcementedpastebackfillrheologybehavioranddamageevolution AT chaoyujiang insituremediationofphosphogypsumwithwaterwashingpretreatmentusingcementedpastebackfillrheologybehavioranddamageevolution AT chongchongqi insituremediationofphosphogypsumwithwaterwashingpretreatmentusingcementedpastebackfillrheologybehavioranddamageevolution |