Transformation of Flue-Gas-Desulfurization Gypsum to α-Hemihydrated Gypsum in Salt Solution at Atmospheric Pressure

›› 2011, Vol. 19 ›› Issue (2): 349-355.

• PRODUCT ENGINEERING AND CHEMICAL TECHNOLOGY • Previous Articles

Transformation of Flue-Gas-Desulfurization Gypsum to α-Hemihydrated Gypsum in Salt Solution at Atmospheric Pressure

WU Xiaoqin¹, TONG Shitang¹, GUAN Baohong², WU Zhongbiao²

1. Department of Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;
2. Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, China

Received:2009-11-24 Revised:2010-11-30 Online:2011-04-28 Published:2011-04-28
Supported by:
Supported by the National High Technology Research and Development Program of China(2006AA06Z385);the Science Foundation of Wuhan University of Science and Technology(2008RC06)

Transformation of Flue-Gas-Desulfurization Gypsum to α-Hemihydrated Gypsum in Salt Solution at Atmospheric Pressure

吴晓琴¹, 童仕唐¹, 官宝红², 吴忠标²

1. Department of Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;
2. Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, China

通讯作者: WU Xiaoqin,E-mail:leafwu205@yahoo.com.cn
基金资助:
Supported by the National High Technology Research and Development Program of China(2006AA06Z385);the Science Foundation of Wuhan University of Science and Technology(2008RC06)

Abstract

Abstract: Direct phase transformation of flue gas desulfurization gypsum in hot salt solution at atmospheric pres-sure was investigated.The effects of temperature,salt species,salt concentration,solids content,pH and modifier were examined.The crystals obtained under different conditions and solubility of calcium sulfate in contact with solid gypsum were also determined.α-Calcium sulfate hemihydrate crystals of stubby columnar shape and regular pentahedral sides were obtained under the following conditions:salt concentration 20%-30%,operation tempera-ture 95-100℃,solids mass content in the slurry 10%-30% and neutral pH.Thermodynamic analysis revealed that phase transformation of calcium sulfate dihydrate to α-calcium sulfate hemihydrate occurs because of the difference in solubilities between the two solid gypsum phases in this system.

Key words: flue gas desulfurization gypsum, crystal growth, thermogravimetric analysis, phase transformation

摘要： Direct phase transformation of flue gas desulfurization gypsum in hot salt solution at atmospheric pres-sure was investigated.The effects of temperature,salt species,salt concentration,solids content,pH and modifier were examined.The crystals obtained under different conditions and solubility of calcium sulfate in contact with solid gypsum were also determined.α-Calcium sulfate hemihydrate crystals of stubby columnar shape and regular pentahedral sides were obtained under the following conditions:salt concentration 20%-30%,operation tempera-ture 95-100℃,solids mass content in the slurry 10%-30% and neutral pH.Thermodynamic analysis revealed that phase transformation of calcium sulfate dihydrate to α-calcium sulfate hemihydrate occurs because of the difference in solubilities between the two solid gypsum phases in this system.

关键词: flue gas desulfurization gypsum, crystal growth, thermogravimetric analysis, phase transformation

WU Xiaoqin, TONG Shitang, GUAN Baohong, WU Zhongbiao. Transformation of Flue-Gas-Desulfurization Gypsum to α-Hemihydrated Gypsum in Salt Solution at Atmospheric Pressure[J]. , 2011, 19(2): 349-355.

吴晓琴, 童仕唐, 官宝红, 吴忠标. Transformation of Flue-Gas-Desulfurization Gypsum to α-Hemihydrated Gypsum in Salt Solution at Atmospheric Pressure[J]. , 2011, 19(2): 349-355.

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Transformation of Flue-Gas-Desulfurization Gypsum to α-Hemihydrated Gypsum in Salt Solution at Atmospheric Pressure

Transformation of Flue-Gas-Desulfurization Gypsum to α-Hemihydrated Gypsum in Salt Solution at Atmospheric Pressure

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