Stability of K-struvite in High Temperature and Acid-base Environment

Abstract

K-struvite was prepared by precipitation method, and the stability of K-struvite in high temperature and acid-base environment were investigated by X-ray diffraction (XRD), thermogravimetric analysis (TG/DSC), and infrared spectroscopy (FT-IR). The results show that K-struvite decomposes from 50 to 110 °C, and the mass loss begins at 50 °C before being completely destroyed at 110 °C, then further heating at temperature above 500 °C leading to complete loss of the binding water in K-struvite. Moreover, K-struvite is more stable in alkaline environments than acidic environment.

Keywords

K-struvite / temperature / magnesium potassium phosphate cement / acid-base environment

References

[1] Qin J, Qian J, Song Q, et al. Research Progress on Magnesium Phosphate Cement[J]. Journal of the Chinese Ceramic Society, 2022, 50(06): 1592-1606. (in Chinese)

[2] Liu J, Guo R, Zhang Zengqi. Research Progress of Properties of Magnesium Phosphate Cement[J]. Materials Reports, 2021, 35(23): 23068-23075. (in Chinese)

[3] Chen J, Huang L, Dong Long. Hydration Behavior of MgO Surface: A First-principles Study[J]. Applied Surface Science, 2023, 611: 155 441.1-155 441.9. Part A

[4] Hugo L. Céline Cau Dit Coumes, Cyrille Mercier. Influence of the w/c Ratio on the Hydration Process of a Magnesium Phosphate Cement and on Its Retardation by Boric Acid[J]. Cement and Concrete Research, 2018, 109: 159-174.

[5] Lai Zhenyu. Immobilization of Medium and Low Level Radioactive Wastes by Magnesium Phosphate Cement, 2012 Chongqing: Chongqing University. (in Chinese)

[6] Wagh A S, Jeong S Y. Chemically Bonded Phosphate Ceramics: I, A Dissolution Model of Formation[J]. Journal of the American Ceramic Society, 2003, 86(11): 1838-1844.

[7] Wagh A S. Chemically Bonded Phosphate Ceramics, 2016, 86(11): 17-34.

[8] Sarkar A K. Hydration/dehydration Characteristics of Struvite and Dittmarite Pertaining to Magnesium Ammonium Phosphate Cement Systems[J]. Journal of Materials Science, 1991, 26(9): 2514-2518.

[9] Bei A, Jh S. Phase Changes on Heating Ammonium Magnesium Phosphate Hydrates[J]. Thermochimica Acta, 1988, 129(2): 197-215.

[10] Lai Z, Qian J, Lu Z, et al. Effects of Different Temperature Treatment to Properties of Magnesium Phosphate Cement [J]. Journal of Functional Materials, 2012, 43(15): 2065-2070. (in Chinese)

[11] Chen Y, Wang Z, Peng X, et al. Effect of High Temperature and Carbonization on Chloride Binding Stability in Calcium Aluminate Cement[J]. Journal of Building Materials, 2022, 25(07): 715-721. (in Chinese)

[12] Gu K, Chen Bing. Mechanism of Citric Acid and Ammonium Citrate Tribasic on Improving Water Stability of Magnesium Oxychloride Cement[J]. Journal of Building Materials, 2022, 25(05): 441-446. (in Chinese)

[13] LIANG Yongning, YUAN Yingshu. Mechanism of Concrete Destruction Under Sodium Sulfate and Magnesium Sulfate Solution[J]. Journal of the Chinese Ceramic Society, 2007, (04): 504–508(in Chinese)

[14] Wang Hongtao. Study on the High Performance Magnesia-Phosphate Cement Based Composites, 2006 Chongqing: Chongqing University. (in Chinese)

[15] CHEN Bing, LUO Yali, WANG Jing. Study on Performance of Magnesium Phosphate Cement[J]. Cement, 2010(07): 14–18(in Chinese)

[16] You Chao. Hydration and Hardening of Magnesium Phosphate Cement and Stability of Hydration Products, 2017 Chongqing: Chongqing University. (in Chinese)

[17] ZHANG Tao, CHEN Huisu, LI Xiangyu, et al. Hydration Behavior of Magnesium Potassium Phosphate Cement and Stability Analysis of Its Hydration Products Through Thermodynamic Modeling[J]. Cement and Concrete Research, 2017(98): 101–110

[18] Chauhan, Chetan K, Joshi, Mihirkumar J. Growth and Characterization of Struvite-Na Crystals[J]. Journal of Crystal Growth, 2014(401): 221–226

[19] Rouzic M L, Thierry C, Gerard P, et al. Mechanisms of K-struvite Formation in Magnesium Phosphate Cements[J]. Cement and Concrete Research, 2017(91): 117–122

[20] LI Guoxin, ZHANG Junjie, ZHANG Ge. Mechanical Property and Water Stability of the Novel CSA-MKPC Blended System[J]. Construction & Building Materials, 2017(136): 99–107

[21] Liu N, Jiang Z, Wang H, et al. Quantitative Analysis of Hydration Products K-struvite in Magnesium Potassium Phosphate Cement[J]. Materials Reports, 2017, 31(24): 45-49. (in Chinese)

[22] Chang Y, Shi C, Yang N, et al. Research Progresses on Durability of Magnesium Phosphate Cement Based Materials[J]. Journal of the Chinese Ceramic Society, 2014, 42(04): 486-493. (in Chinese)

[23] Li Y, Shi T, Sun Jia. Experimental Study on the Performance of Magnesium Phosphate Cement in Alkali[J]. Journal of Building Materials, 2015, 18(06): 1060-1064. +1 083(in Chinese)

[24] Payam S, Sumra Y, Zainah Ibrahim. Affecting the pH Measurement of Cement Mortars[J]. Journal of Wuhan University of Technology-Materials Science Edition, 2021, 36(05): 689-696.

[25] Li D, Li P, Feng Chunhua. Research on Water Resistance of Magnesium Phosphate Cement[J]. Journal of Building Materials, 2009, 12(05): 505-510. (in Chinese)