SCI和EI收录∣中国化工学会会刊

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

• • 上一篇    

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. 1. Department of Chemical Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;
    2. Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, China
  • 收稿日期:2009-11-24 修回日期:2010-11-30 出版日期:2011-04-28 发布日期:2011-04-28
  • 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)

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. 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)

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

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