Calcium sulfate whisker prepared by flue gas desulfurization gypsum: A physical–chemical coupling production process

In this paper, utilizing the purified flue gas desulfurization (FGD) gypsum as raw materials to prepare calcium sulfate whisker (CSW) by hydrothermal method, the effects of the dosage of crystal modifier, reaction temperature, pH, etc. on the crystal morphology of CSW were discussed. The results show that the purified FGD gypsum can replace high-quality natural gypsum for the preparation of the CSW with excellent quality. The dosage of crystal modifier (K2SO4) and reaction temperature have a significant effect on the morphology and aspect ratio of CSW, while pH and reaction time have a minor effect. When the dosage of K2SO4 is 3 wt%, pH is adjusted to 2 and the solution is reacted at 130 °C for 60 min, CSW with excellent quality can be obtained.

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Kinetic model for calcium sulfate α-hemihydrate produced hydrothermally from gypsum formed by flue gas desulfurization

Journal of Applied Crystallography ◽

10.1107/s1600576715007141 ◽

2015 ◽

Vol 48 (3) ◽

pp. 827-835 ◽

Cited By ~ 10

Author(s):

Mingliang Tang ◽

Xuerun Li ◽

Yusheng Shen ◽

Xiaodong Shen

Keyword(s):

Flue Gas ◽

Calcium Sulfate ◽

High Performance ◽

Transformation Process ◽

Flue Gas Desulfurization ◽

Synthesis Process ◽

Stable Phase ◽

Hydrothermal Conditions ◽

Simple Method ◽

Kinetics Of

Modeling of the kinetics of the synthesis process for calcium sulfate α-hemihydrate from gypsum formed by flue gas desulfurization (FGD) is important to produce high-performance products with minimal costs and production cycles under hydrothermal conditions. In this study, a model was established by horizontally translating the obtained crystal size distribution (CSD) to the CSD of the stable phase during the transformation process. A simple method was used to obtain the nucleation and growth rates. A nonlinear optimization algorithm method was employed to determine the kinetic parameters. The model can be successfully used to analyze the transformation kinetics of FGD gypsum to α-hemihydrate in an isothermal batch crystallizer. The results showed that the transformation temperature and stirring speed exhibit a significant influence on the crystal growth and nucleation rates of α-hemihydrate, thus altering the transformation time and CSD of the final products. The characteristics obtained by the proposed model can potentially be used in the production of α-hemihydrate.

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Study of the Influence of Calcium Sulfate on Fly Ash/Ca(OH)2Sorbents for Flue Gas Desulfurization

Energy & Fuels ◽

10.1021/ef020291s ◽

2003 ◽

Vol 17 (5) ◽

pp. 1330-1337 ◽

Cited By ~ 13

Author(s):

J. Fernández ◽

M. J. Renedo

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Calcium Sulfate ◽

Flue Gas Desulfurization

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Application and Research of High Molecular Carboxylates in Desulphurization System of Thermal Power Plant

Materials Science Forum ◽

10.4028/www.scientific.net/msf.917.175 ◽

2018 ◽

Vol 917 ◽

pp. 175-179

Author(s):

Yan Chang Kang ◽

Bing Li ◽

Qi Long Zhang

Keyword(s):

Flue Gas ◽

Calcium Sulfate ◽

Power Plants ◽

Thermal Power ◽

Test Method ◽

Flue Gas Desulfurization ◽

Carboxyl Groups ◽

Chemical Absorption ◽

Sulfite Oxidation ◽

Main Components

The main components of polymer carboxyl group are introduced.The effects of macromolecular carboxyl groups on the limestone-gypsum wet flue gas desulfurization (FGD) system of coal-fired power plants in China were studied by test method. The results showed that the macromolecular carboxyl groups can accelerate the chemical absorption of SO2 under the action of active agents and crystallization agents, improve the desulfurization efficiency of about 2%, and shorten the limestone ablation time of more than 40%, catalytic calcium sulfite oxidation of calcium sulfate.

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On Experimental Study of Development Calcined Gypsum from Flue Gas Desulfurization by Microwave Technology

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.368-370.780 ◽

2013 ◽

Vol 368-370 ◽

pp. 780-784 ◽

Cited By ~ 1

Author(s):

Zhi Man Zhao ◽

Chun Jie Wang ◽

Can Qion Li ◽

Xiao Mei Zhang

Keyword(s):

Microwave Irradiation ◽

Flue Gas ◽

Calcium Sulfate ◽

Setting Time ◽

Flue Gas Desulfurization ◽

Crystal Formation ◽

Special Effect ◽

Fgd Gypsum ◽

Calcined Gypsum ◽

Cylindrical Crystal

Flue gas desulfurization gypsum (FGD gypsum) was irradiated with microwave, it could be changed calcined gypsum from flue gas desulfurization (CGD). The microwave respectively irradiated five groups FGD gypsum at 100-110°C, 110-120°C, 120-130°C, 130-140°C and 140-150°C, then the fineness and setting time were respectively measured, and compressive/flexural strength were also determined after 2 hours. Experiments show that, CaSO4·0.5H2O crystal of CGD would be more quantity and bigger volume with irradiation temperature increasing. The reason was considered that there were special effect of microwave irradiation to calcium sulfate crystalsthat by scanning electron microscope, and found the Ca, S, O and other elements in cylindrical crystal by Edax. The formation mechanism of CaSO4·0.5H2O crystal by microwave irradiation is different from traditional CaSO4·0.5H2O crystal formation theories.

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