Cargando…

The Influences of Soluble Phosphorus on Hydration Process and Mechanical Properties of Hemihydrate Gypsum under Deep Retarding Condition

Phospho-gypsum is an industrial solid waste discharged from the phosphate production process. The waste includes complex impurities such as phosphoric acid and its salts, fluoride, and organics. Usually, retarders are mixed in gypsum-based building materials to extend setting time. Although the effe...

Descripción completa

Detalles Bibliográficos
Autores principales: Fan, Puyue, Zhang, Mingtao, Zhao, Min, Peng, Jiahui, Gao, Kai, Huang, Jing, Yi, Wei, Zhu, Cong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9000870/
https://www.ncbi.nlm.nih.gov/pubmed/35408012
http://dx.doi.org/10.3390/ma15072680
_version_ 1784685543479574528
author Fan, Puyue
Zhang, Mingtao
Zhao, Min
Peng, Jiahui
Gao, Kai
Huang, Jing
Yi, Wei
Zhu, Cong
author_facet Fan, Puyue
Zhang, Mingtao
Zhao, Min
Peng, Jiahui
Gao, Kai
Huang, Jing
Yi, Wei
Zhu, Cong
author_sort Fan, Puyue
collection PubMed
description Phospho-gypsum is an industrial solid waste discharged from the phosphate production process. The waste includes complex impurities such as phosphoric acid and its salts, fluoride, and organics. Usually, retarders are mixed in gypsum-based building materials to extend setting time. Although the effects of the impurities on hydration properties and the mechanical strength of calcined gypsum have been analyzed, the impact and mechanism of soluble phosphorus on the phospho-gypsum under retardation is yet to be defined. In this study, we employed thermogravimetry (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM) to evaluate the hydration kinetics, phase transformation, structure, and morphology of the calcined gypsum. The data showed that the retarder or soluble phosphorus prolonged the setting time. A single retarder considerably shortened the initial setting time from 95 min to 60 min, even at the lowest dosage of 0.1 wt.% soluble phosphorus. In addition, drying flexural and compressive strengths were markedly decreased. On the other hand, the induction period was advanced with extension of acceleration and deceleration stage. SEM results indicated that the crystal morphology of the gypsum changed from a long to short column or block. An EDS analysis showed that phosphates were concentrated on the surface of gypsum crystals.
format Online
Article
Text
id pubmed-9000870
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-90008702022-04-12 The Influences of Soluble Phosphorus on Hydration Process and Mechanical Properties of Hemihydrate Gypsum under Deep Retarding Condition Fan, Puyue Zhang, Mingtao Zhao, Min Peng, Jiahui Gao, Kai Huang, Jing Yi, Wei Zhu, Cong Materials (Basel) Article Phospho-gypsum is an industrial solid waste discharged from the phosphate production process. The waste includes complex impurities such as phosphoric acid and its salts, fluoride, and organics. Usually, retarders are mixed in gypsum-based building materials to extend setting time. Although the effects of the impurities on hydration properties and the mechanical strength of calcined gypsum have been analyzed, the impact and mechanism of soluble phosphorus on the phospho-gypsum under retardation is yet to be defined. In this study, we employed thermogravimetry (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM) to evaluate the hydration kinetics, phase transformation, structure, and morphology of the calcined gypsum. The data showed that the retarder or soluble phosphorus prolonged the setting time. A single retarder considerably shortened the initial setting time from 95 min to 60 min, even at the lowest dosage of 0.1 wt.% soluble phosphorus. In addition, drying flexural and compressive strengths were markedly decreased. On the other hand, the induction period was advanced with extension of acceleration and deceleration stage. SEM results indicated that the crystal morphology of the gypsum changed from a long to short column or block. An EDS analysis showed that phosphates were concentrated on the surface of gypsum crystals. MDPI 2022-04-05 /pmc/articles/PMC9000870/ /pubmed/35408012 http://dx.doi.org/10.3390/ma15072680 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Fan, Puyue
Zhang, Mingtao
Zhao, Min
Peng, Jiahui
Gao, Kai
Huang, Jing
Yi, Wei
Zhu, Cong
The Influences of Soluble Phosphorus on Hydration Process and Mechanical Properties of Hemihydrate Gypsum under Deep Retarding Condition
title The Influences of Soluble Phosphorus on Hydration Process and Mechanical Properties of Hemihydrate Gypsum under Deep Retarding Condition
title_full The Influences of Soluble Phosphorus on Hydration Process and Mechanical Properties of Hemihydrate Gypsum under Deep Retarding Condition
title_fullStr The Influences of Soluble Phosphorus on Hydration Process and Mechanical Properties of Hemihydrate Gypsum under Deep Retarding Condition
title_full_unstemmed The Influences of Soluble Phosphorus on Hydration Process and Mechanical Properties of Hemihydrate Gypsum under Deep Retarding Condition
title_short The Influences of Soluble Phosphorus on Hydration Process and Mechanical Properties of Hemihydrate Gypsum under Deep Retarding Condition
title_sort influences of soluble phosphorus on hydration process and mechanical properties of hemihydrate gypsum under deep retarding condition
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9000870/
https://www.ncbi.nlm.nih.gov/pubmed/35408012
http://dx.doi.org/10.3390/ma15072680
work_keys_str_mv AT fanpuyue theinfluencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT zhangmingtao theinfluencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT zhaomin theinfluencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT pengjiahui theinfluencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT gaokai theinfluencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT huangjing theinfluencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT yiwei theinfluencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT zhucong theinfluencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT fanpuyue influencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT zhangmingtao influencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT zhaomin influencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT pengjiahui influencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT gaokai influencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT huangjing influencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT yiwei influencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition
AT zhucong influencesofsolublephosphorusonhydrationprocessandmechanicalpropertiesofhemihydrategypsumunderdeepretardingcondition