Effect of Preparation Process of Pressurized Aqueous Solution Method on Properties of α-High Strength Gypsum

Abstract

Abstract: The high strength gypsum is prepared from desulfurization gypsum by pressurized aqueous solution method, and its process parameters are the key to determine the preparation quality of the high strength gypsum. The effects of hydrothermal temperature, hydrothermal time, stirring speed and slurry concentration on the properties of α-high strength gypsum were studied. The crystal morphology and gypsum phase composition of the samples prepared under different process parameters were qualitatively and quantitatively analyzed, and the optimal preparation process of α-high strength gypsum by pressurized aqueous solution method was optimized. The results show that the hydrothermal temperature has a great influence on the size and aspect ratio of the generated crystals, while the hydrothermal time mainly affects the size of the crystals and has little influence on the aspect ratio. While the hydrothermal temperature and hydrothermal time are important factors affecting the phase composition of α-high strength gypsum. The stirring speed and slurry concentration mainly affect the size and the aspect ratio of the high strength gypsum and have little influence on the composition of the gypsum phase. Under the optimum process conditions: the hydrothermal temperature of 130 ℃, the hydrothermal time of 4 h, the stirring speed of 250 r/min and the slurry concentration of 30% (mass fraction), the 2 h flexural strength of α-high strength gypsum is 5.4 MPa and the drying compressive strength of 41.9 MPa.

Key words: α-high strength gypsum, process parameter, aspect ratio, gypsum phase composition, pressurized aqueous solution method

CLC Number:

TQ177

HAN Kang, GUAN Xuemao, WANG Yanfeng, LIU Songhui, LI Yifan. Effect of Preparation Process of Pressurized Aqueous Solution Method on Properties of α-High Strength Gypsum[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(5): 1620-1630.

References

[1] 李逸晨.石膏行业的发展现状及趋势[J].硫酸工业,2019(11):1-7+13.
LI Y C. Development status and trend of gypsum industry[J]. Sulphuric Acid Industry, 2019(11): 1-7+13 (in Chinese).
[2] 陈晓龙,梁川,宋大勇.燃煤发电企业固体废弃物的资源化利用研究综述[J].东北电力技术,2020,41(7):27-30+59.
CHEN X L, LIANG C, SONG D Y. Research on resource utilization of solid waste in coal-fired power plants[J]. Northeast Electric Power Technology, 2020, 41(7): 27-30+59 (in Chinese).
[3] 姜春志,董风芝.工业副产石膏的综合利用及研究进展[J].山东化工,2016,45(9):42-44+47.
JIANG C Z, DONG F Z. Comprehensive utilization and research progress of industrial by-product gypsum[J]. Shandong Chemical Industry, 2016, 45(9): 42-44+47 (in Chinese).
[4] 彭明强,叶蓓红.脱硫石膏用于自流平砂浆的研究[J].建筑材料学报,2012,15(3):406-409+421.
PENG M Q, YE B H. Preparation of self-leveling mortar with FGD gypsum[J]. Journal of Building Materials, 2012, 15(3): 406-409+421 (in Chinese).
[5] 董辰光,徐东宇,梁晓杰.脱硫石膏替代天然石膏在水泥中的应用[J].商品混凝土,2020(7):74-77.
DONG C G, XU D Y, LIANG X J. Application of desulfurized gypsum in cement instead of natural gypsum[J].Ready-Mixed Concrete, 2020(7): 74-77 (in Chinese).
[6] 王博,孙振平.脱硫石膏制备高强石膏工艺现状[J].粉煤灰,2017,29(1):13-14+25.
WANG B, SUN Z P. The-state-of-the-arts of preparation process of high strength gypsum with FGD gypsum[J]. Coal Ash, 2017, 29(1): 13-14+25 (in Chinese).
[7] 刘红霞.常压盐溶液法α-半水脱硫石膏的制备及晶形调控研究[D].重庆:重庆大学,2010.
LIU H X. Research on preparation and crystal morphology control of the α-hemihydrate flue gas desulfurization gypsum by salt solution method at atmospheric pressure[D]. Chongqing: Chongqing University, 2010 (in Chinese).
[8] LU W D, MA B G, SU Y, et al. Preparation of α-hemihydrate gypsum from phosphogypsum in recycling CaCl₂ solution[J]. Construction and Building Materials, 2019, 214: 399-412.
[9] JIANG G M, WANG H, CHEN Q S, et al. Preparation of alpha-calcium sulfate hemihydrate from FGD gypsum in chloride-free Ca(NO₃)₂ solution under mild conditions[J]. Fuel, 2016, 174: 235-241.
[10] 桂苗苗,丛钢.脱硫石膏蒸压法制α半水石膏的研究[J].重庆建筑大学学报,2001,23(1):62-65+81.
GUI M M, CONG G. Study on the α-hemihydrate gypsum made by desulphogypsum through autoclave process[J]. Journal of Chongqing Jianzhu University, 2001, 23(1): 62-65+81 (in Chinese).
[11] 罗东燕,邱树恒,陈霏,等.用蒸压法将磷石膏制备α半水石膏的研究[J].新型建筑材料,2015,42(9):23-26+46.
LUO D Y, QIU S H, CHEN F, et al. The research of using phosphogypsum manufacture of α-semi-hydrated gypsum by autoclaved method[J]. New Building Materials, 2015, 42(9): 23-26+46 (in Chinese).
[12] 陈燕.石膏建筑材料[M].北京:中国建材工业出版社,2003:163.
CHEN Y. Gypsum building materials[M]. Beijing: China Building Materials Industry Press, 2003: 163 (in Chinese).
[13] 陈霏,朱芳雯,陈向荣,等.工业副产石膏制备高强石膏的研究应用综述[J].建材发展导向,2014,12(8):24-26.
CHEN F, ZHU F W, CHEN X R, et al. Research and application of high strength gypsum prepared from industrial by-product gypsum[J]. Development Guide to Building Materials, 2014, 12(8): 24-26 (in Chinese).
[14] 张巨松,郑万荣,陈华,等.影响α半水石膏粒度、形貌及强度的因素[J].沈阳建筑大学学报(自然科学版),2006,22(6):930-934.
ZHANG J S, ZHENG W R, CHEN H, et al. Research of some actors on influencing the granularity, morphology and strength of alpha-hemihydrate gypsum[J]. Journal of Shenyang Jianzhu University (Natural Science), 2006, 22(6): 930-934 (in Chinese).
[15] 张巨松,孙蓬,鞠成,等.转晶剂对脱硫石膏制备α-半水石膏形貌及强度的影响[J].沈阳建筑大学学报(自然科学版),2009,25(3):521-525.
ZHANG J S, SUN P, JU C, et al. Influence of crystal modifier on morphology and strength of α-hemihydrate gypsum prepared by desulfurization gypsum[J]. Journal of Shenyang Jianzhu University (Natural Science), 2009, 25(3): 521-525 (in Chinese).
[16] 郑万荣,高洋,高飞,等.加压水溶液法制备α半水石膏技术的几个问题[J].非金属矿,2007,30(4):4-7.
ZHENG W R, GAO Y, GAO F, et al. Some questions on preparation of α-hemihydrate gypsum with hydrothermal method in pressure[J]. Non-Metallic Mines, 2007, 30(4): 4-7 (in Chinese).
[17] 段珍华,秦鸿根,李岗.动态水热法制备高强α-半水石膏的工艺参数研究[J].粉煤灰,2009,21(1):6-7+22.
DUAN Z H, QIN H G, LI G. Process parameter study of preparation of α-hemihydrates desulfurized gypsum with dynamic hydrothermal method[J]. Coal Ash, 2009, 21(1): 6-7+22 (in Chinese).
[18] YOUNG R A. The rietveld method[M]. New York: Oxford University Press, 1995.
[19] 刘先锋,吴大昌,魏桂芳,等.反应温度对水热法α-半水脱硫石膏的影响[J].环境科学与技术,2012,35(s1):26-28+101.
LIU X F, WU D C, WEI G F, et al. The effect of reaction temperature on the preparation of α-calcium sulfate hemihydrate from FGD gypsum using the hydrothermal method[J]. Environmental Science & Technology, 2012, 35(s1): 26-28+101 (in Chinese).
[20] 汪潇.脱硫石膏晶须制备与稳定化一体技术[M].北京:冶金工业出版社,2017:31-32.
WANG X. Integrated technology of desulfurization gypsum whisker preparation and stabilization[M]. Beijing: Metallurgical Industry Press, 2017: 31-32 (in Chinese).
[21] JIANG G M, MAO J W, FU H L, et al. Insight into metastable lifetime of α-calcium sulfate hemihydrate in CaCl₂ solution[J]. Journal of the American Ceramic Society, 2013, 96(10): 3265-3271.
[22] 赵珊茸.结晶学及矿物学[M].北京:高等教育出版社,2004:149-150.
ZHAO S R. Crystallography and mineralogy[M]. Beijing: Higher Education Press, 2004: 149-150 (in Chinese).
[23] 郑燕青,施尔畏,李汶军,等.晶体生长理论研究现状与发展[J].无机材料学报,1999,14(3):321-332.
ZHENG Y Q, SHI E W, LI W J, et al. Research and development of the theories of crystal growth[J]. Journal of Inorganic Materials, 1999, 14(3): 321-332 (in Chinese).
[24] 杨林,张冰,周杰,等.磷石膏制备α型高强石膏及其转化过程研究[J].建筑材料学报,2014,17(1):147-152.
YANG L, ZHANG B, ZHOU J, et al. Preparation of α-high strength gypsum using phosphogypsum and transformation of phosphogypsum to α-high strength gypsum[J]. Journal of Building Materials, 2014, 17(1): 147-152 (in Chinese).