Comparative Analysis of Two National Standard Methods for Chloride Ions in Flue Gas Desulfurization Gypsum

Yudong Huang; Zhuang Li; Yongbin He

doi:10.6919/ICJE.202505_11(5).0004

Authors

Yudong Huang
Zhuang Li
Yongbin He

DOI:

https://doi.org/10.6919/ICJE.202505_11(5).0004

Keywords:

Coal-fired Power Plants; FGD Gypsum; Chloride Ion; Silver Nitrate Titration; Ion Chromatography.

Abstract

This study addresses the significant discrepancy in results when determining chloride ion content in flue gas desulfurization (FGD) gypsum using two different national standard methods: GB/T 5484-2024 "Chemical Analysis Methods for Gypsum" and GB/T 176-2017 "Chemical Analysis Methods for Cement." A comparative analysis of the two standard methods was conducted. Results show that compared to silver nitrate titration, the ion chromatography method demonstrated relative standard deviations of 0-5.56% across three samples, produced results closer to the true values when testing standard samples, and exhibited higher accuracy, making it more suitable for determining chloride content in low-concentration gypsum samples. Method validation revealed a detection limit of 0.0002% for chloride ions, precision of 9.1%, and spike recovery rates between 84.5% and 98.5%. This method's low detection limit and high accuracy provide valuable reference for frontline testing applications.

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References

[1] Tang L, Qu J B, Mi Z F, et al. Substantial emission reductions from Chinese power plants after the introduction of ultra-low emissions standards[J]. Nature Energy, 2019, 4(11): 929–938.

[2] Wang W, Xu Y, Xue, J, et al. The research progress and suggestions of desulfurization technology in coal-fired power plants[J]. Electric Power Technology and Environmental Protection, 2020, 36(3), 1-5.

[3] Zhu Y L; Zhao Y H; Zhang S; et al. Progress in desulfurization technology for coal-fired power plants [J]. Tianjin Chemical Industry, 2018, 32 (02): 1-3.

[4] Liu Z, Qian W, Xu H, et al. Study on gypsum dehydration in desulfurization system of coal-fired power plants[J]. Energy Engineering, 2024, 44(5): 81-85.

[5] Guo Y L, Li H. Investigation of Determination Chloride ions in FGD Waste Water With Silver Nitrate Volumetric[J]. Total Corrosion Control, 2018, 32(04): 4-6.

[6] Tang Y Y, Cui C S. Determination of Chloride Content by Silver Nitrate Titration-On the Judgment of the Titration Endpoint[J]. Construction Safety, 2021, 36 (10): 76-79.

[7] Liang K H, Li B, Yan W H. Application exploration of chloride ion determination method in ammonia desulfurization slurry [J]. Chemical Management, 2019, (16): 35-36.

[8] Li Y S, Guo H. Progress in determination methods of chloride ions in industrial water [J]. Industrial Water Treatment, 2007, (04): 1-5.

[9] Wang X Q, Hu X S, Xu F, et al. Determination of Water-soluble Fluorine and Chloride Ions in Phosphogypsum by Ion Chromatography [J]. Yunnan Chemical Technology, 2023, 50(8): 69-71.

[10] GB/T 5484-2012, Methods for chemical analysis of gypsum[S].

[11] GB/T 176-2008, Methods for chemical analysis of cement [S].