Influence of crystal-transforming agent on the performance and mechanism of α-high-strength gypsum prepared from FGD gypsum--颗粒学报PARTICUOLOGY

Xu, Z., Wang, X., Jin, B., Zhang, D., & Li, H. (2024). Influence of crystal-transforming agent on the performance and mechanism of α-high-strength gypsum prepared from FGD gypsum. Particuology, 87, 37-45. https://doi.org/10.1016/j.partic.2023.07.015

Influence of crystal-transforming agent on the performance and mechanism of α-high-strength gypsum prepared from FGD gypsum

Zhuoyue Xu ^{a b *}, Xiao Wang ^b, Biao Jin ^b, Dawang Zhang ^a, Hui Li ^a

a College of Materials Science and Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
b School of Materials and Chemical Engineering, Henan University of Urban Construction, Pingdingshan, 467036, China

10.1016/j.partic.2023.07.015

Volume 87, April 2024, Pages 37-45

Received 20 May 2023, Revised 10 July 2023, Accepted 16 July 2023, Available online 4 August 2023, Version of Record 21 August 2023.

E-mail: 1312004357@qq.com

Highlights

• Effect of a crystal-transforming agent on the performance and mechanism of FGD gypsum.

• Tiny, macro, and formation mechanisms of α-high-strength gypsum under action of a crystal modifier were explored.

• Better-prepared α-high-strength gypsum crystals are short columnar, with an aspect ratio in the range of 1–3.

Abstract

This paper investigates the impact of flue gas desulfurization (FGD) gypsum's crystal modifier on the characteristics and microcosmic mechanism of α-high strength gypsum. The results demonstrate that all three crystal modifiers can convert FGD gypsum to α-high-strength gypsum. Citric acid (CA) has the most significant influence on α-high-strength gypsum, and the prepared α-high-strength gypsum is short columnar, with an aspect ratio in the range of 1–3, and has a faster setting time, a larger specific surface area, and a smaller standard consistency, higher compressive strength, greater surface hardness, and smaller crystal particle size. The initial setting time of the α-high-strength gypsum manufactured with CA crystal modifier was decreased by 36% compared to the blank sample, the final setting time was lowered by 37.5%, and the water consumption of the standard consistency was reduced by 8%. The maximum strength is 32 MPa after 2 h, the absolute dry compressive strength is up to 38 MPa, and the surface hardness is improved by 24.43%.

Graphical abstract

Keywords

Flue gas desulfurization gypsum; Crystal modifier; Microscopic mechanism; α-high-strength gypsum

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