Effect of Retarder on Properties of β-Hemihydrate Phosphogypsum-Ordinary Portland Cement Composite System and Its Mechanism

Abstract

Abstract: β-hemihydrate phosphogypsum (β-HPG) has poor mechanical properties and fast setting and hardening. Previous studies have shown that replacing part of β-HPG by ordinary Portland cement (OPC) can improve the mechanical properties of the composite system, but the regulation and mechanism on the workability of this composite system are still unclear. The effects of three retarders on the properties of β-HPG-OPC composite system were investigated in this paper. The macro-performance was characterized by setting time and compressive strength test. The mechanism was discussed by hydrating exothermic curve, conductivity curve, XRD pattern and SEM image. The results show that sodium tripolyphosphate (STPP) has no retarding effect on the composite system. Protein SC retarder (SC) and citric acid (CA) have excellent retarding effect on the composite system, among which SC has better retarding effect on the initial setting time, and CA has better delaying effect on the final setting time. The incorporation of CA changes the morphology of dihydrate gypsum, resulting in a significant decrease of compressive strength of the system. The coarsening effect of SC on dihydrate gypsum makes the system to form a relatively dense microstructure, which has little influence on the compressive strength. The research results will provide an important reference for the engineering application of the β-HPG-OPC composite system, and help to promote the high value-added utilization of β-HPG in the engineering.

Key words: β-hemihydrate phosphogypsum, ordinary Portland cement, composite system, retarder, setting time, compressive strength, retarding mechanism

CLC Number:

TQ177.3⁺7

MA Baoguo, WU Lei, CHEN Pian, QI Huahui, JIN Zihao, YANG Qi. Effect of Retarder on Properties of β-Hemihydrate Phosphogypsum-Ordinary Portland Cement Composite System and Its Mechanism[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(7): 2411-2420.

References

[1] 代慧.磷石膏通过双极膜电渗析法制备硫酸的工艺及机理研究[D].贵阳:贵州大学,2016.
DAI H. Study on the process and mechanism of the preparation of sulfuric acid through bipolar membrane electrodialysis method with solid waste phosphogypsum[D]. Guiyang: Guizhou University, 2016 (in Chinese).
[2] 杨志强,陈晴,郭清春,等.磷石膏在水泥生产中的应用现状与展望[J].硅酸盐通报,2016,35(9):2860-2865.
YANG Z Q, CHEN Q, GUO Q C, et al. Current status and prospects on utilization of phosphogypsum in cement production[J]. Bulletin of the Chinese Ceramic Society, 2016, 35(9): 2860-2865 (in Chinese).
[3] 叶学东.2016年我国磷石膏利用现状、存在问题及建议[J].磷肥与复肥,2017,32(7):1-3.
YE X D. Present status, existing problems and suggestions of phosphogypsum utilization in China in 2016[J]. Phosphate & Compound Fertilizer, 2017, 32(7): 1-3 (in Chinese).
[4] 茹晓红.磷石膏基胶凝材料的制备理论及应用技术研究[D].武汉:武汉理工大学,2013.
RU X H. Processing theory and application technology research of phosphogypsum based gypsum piaster[D]. Wuhan: Wuhan University of Technology, 2013 (in Chinese).
[5] 李前均.α-石膏基自流平材料的制备与性能研究[D].贵阳:贵州大学,2017.
LI Q J. Study on preparation and properties of self-leveling α-gypsum based materials[D]. Guiyang: Guizhou University, 2017 (in Chinese).
[6] 马保国,孙仲达,苏英,等.缓凝剂改性磷建筑石膏及其机理研究[J].硅酸盐通报,2017,36(12):3978-3983+3992.
MA B G, SUN Z D, SU Y, et al. Mechanism research of phosphor building gypsum with retarder modified[J]. Bulletin of the Chinese Ceramic Society, 2017, 36(12): 3978-3983+3992 (in Chinese).
[7] 杨林.利用磷石膏制备建筑材料的研究[D].绵阳:西南科技大学,2013.
YANG L. Study on utilization of phosphogypsum for construction and building materials production[D]. Mianyang: Southwest University of Science and Technology, 2013 (in Chinese).
[8] 马保国,胡鹏辉,苏英,等.磷建筑石膏的凝结时间与强度调控研究[J].硅酸盐通报,2019,38(10):3047-3053.
MA B G, HU P H, SU Y, et al. Study on setting time and strength control of phosphorus building gypsum[J]. Bulletin of the Chinese Ceramic Society, 2019, 38(10): 3047-3053 (in Chinese).
[9] 沈荣熹.杜力克石膏基自流平砂浆的组成、性能与应用[C]//2015中国建筑材料联合会石膏建材分会第六届年会暨第十届全国石膏技术交流大会及展览会论文集,2015:31-35.
SHEN R X. Composition, properties and application of Durick gypsum base self-leveling mortar[C]//2015 the Sixth Annual Conference of Gypsum Building Materials Branch of China Building Materials Federation and the 10th National Gypsum Technical Exchange Conference and Exhibition proceedings, 2015: 31-35 (in Chinese).
[10] 梁旭辉,刘芳,许耀文,等.硅酸盐水泥改性磷建筑石膏及水化机理研究[J].非金属矿,2018,41(2):45-47.
LIANG X H, LIU F, XU Y W, et al. Study on modification of hemihydrate phosphogypsum with ordinary Portland cement and its hydration mechanism[J]. Non-Metallic Mines, 2018, 41(2): 45-47 (in Chinese).
[11] 戴浩,张超,王辉.石膏-水泥-碱-矿渣复合胶凝体系对石膏基自流平砂浆性能的影响[J].中国建材科技,2020,29(6):40-43.
DAI H, ZHANG C, WANG H. Influence of gypsum-cement-slag-alkali mixed binder systems on properties of gypsum based self-leveling mortars[J]. China Building Materials Science & Technology, 2020, 29(6): 40-43 (in Chinese).
[12] 郑光亚,夏举佩,韩跃伟,等.缓凝剂对磷石膏基建筑石膏性能的影响[J].非金属矿,2019,42(5):79-81.
ZHENG G Y, XIA J P, HAN Y W, et al. Effect of retarder on properties of phosphate gypsum based building gypsum[J]. Non-Metallic Mines, 2019, 42(5): 79-81 (in Chinese).
[13] ZHANG Y Y, YANG J S, CAO X Y. Effects of several retarders on setting time and strength of building gypsum[J]. Construction and Building Materials, 2020, 240: 117927.
[14] MALLON T. Retarding action of gypsum plaster retarders of various chemical composition in relation to the pH value of the plaster[J]. ZKG International, 1988, 41(6): 309-311.
[15] 彭家惠,王凤仙,张建新,等.柠檬酸对石膏析晶过饱和度和微结构的影响[J].武汉理工大学学报,2006,28(11):44-47.
PENG J H, WANG F X, ZHANG J X, et al. Effect of citric acid on crystalline habit and crystal morphology of dihydrate[J]. Journal of Wuhan University of Technology, 2006, 28(11): 44-47 (in Chinese).
[16] 穆元冬.减水剂对不同铝酸盐水泥水化凝结行为的影响[D].郑州:郑州大学,2015.
MU Y D. Effect of dispersants on hydration and setting behavior of different calcium aluminate cements[D]. Zhengzhou: Zhengzhou University, 2015 (in Chinese).
[17] 曹青,张铬,郝艳.缓凝剂对脱硫石膏水化的影响及其缓凝机理研究[J].新型建筑材料,2010,37(6):69-71.
CAO Q, ZHANG G, HAO Y. Effect of retarder on the hydration process of FGD and its retarding mechanism[J]. New Building Materials, 2010, 37(6): 69-71 (in Chinese).
[18] 彭家惠,张建新,瞿金东,等.三聚磷酸钠对建筑石膏水化进程的影响及缓凝机理研究[J].硅酸盐通报,2007,26(6):1053-1057.
PENG J H, ZHANG J X, QU J D, et al. Effect of sodium tripolyphosphate on hydration process of building gypsum and its retarding mechanism[J]. Bulletin of the Chinese Ceramic Society, 2007, 26(6): 1053-1057 (in Chinese).
[19] 梁旭辉.磷建筑石膏改性及自流平砂浆制备[D].重庆:重庆大学,2018.
LIANG X H. Study on modification of β-hemihydrate phosphogypsum and preparation of self-leveling screeds[D]. Chongqing: Chongqing University, 2018 (in Chinese).
[20] DING Y, FANG Y C, FANG H, et al. Study on the retarding mechanism and strength loss of gypsum from hydrolyzed wheat protein retarder[J]. Journal of the Korean Ceramic Society, 2015, 52(1): 28-32.
[21] 彭家惠.建筑石膏减水剂与缓凝剂作用机理研究[D].重庆:重庆大学,2004.
PENG J H. Study on action mechanism of water reducers and retarders for building gypsum[D]. Chongqing: Chongqing University, 2004 (in Chinese).
[22] 马保国,黄洪财,蹇守卫,等.新型缓凝剂对建筑石膏性能的影响及机理研究[J].重庆建筑大学学报,2008,30(5):144-147.
MA B G, HUANG H C, JIAN S W, et al. Effects of a new retarder on building gypsum and its mechanism[J]. Journal of Chongqing Jianzhu University, 2008, 30(5): 144-147 (in Chinese).