无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2024, Vol. 56 ›› Issue (4): 105-111.doi: 10.19964/j.issn.1006-4990.2023-0314

• 环境·健康·安全 • 上一篇    下一篇

添加硫酸铝钾煅烧对脱硫石膏制备建筑石膏性能的影响

王升昌(), 郝建英(), 陈佳宁, 田博   

  1. 太原科技大学材料科学与工程学院,山西 太原 030024
  • 收稿日期:2023-06-08 出版日期:2024-04-10 发布日期:2024-04-18
  • 通讯作者: 郝建英,博士,副教授;E-mail:jyty2280@163.com
  • 作者简介:王升昌(1999— ),男,硕士研究生,主要研究方向为固体废弃物的资源化利用;E-mail:wsc1999999@163.com
  • 基金资助:
    山西省基础研究计划项目(202203021211186);太原科技大学研究生教育创新项目(SY2022002)

Effect of calcination on properties of calcined gypsum prepared from desulphurization gypsum with potassium aluminum sulfate

WANG Shengchang(), HAO Jianying(), CHEN Jianing, TIAN Bo   

  1. School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China
  • Received:2023-06-08 Published:2024-04-10 Online:2024-04-18

摘要:

为了解决脱硫石膏利用率较低的问题,同时提高其高附加值,选用硫酸铝钾(KAS,质量分数分别为0、0.3%、0.6%、1.0%)与脱硫石膏混合,经常压煅烧制备建筑石膏,重点研究煅烧温度及KAS掺量对建筑石膏性能及形貌的影响。结果表明:适当的煅烧温度可改善建筑石膏的性能,但煅烧温度过高时,会使建筑石膏表面裂纹增多,性能下降;添加适量的KAS,不仅可以提高建筑石膏的结晶度,而且能促进水化后新相二水石膏(DH)沿b轴方向生长,延缓沿c轴方向生长,降低DH晶体的长径比,使石膏硬化体逐渐密实化,强度显著增加。脱硫石膏中添加0.3%的KAS,经170 ℃煅烧2 h,制备的建筑石膏性能最佳,初凝时间和终凝时间分别为11.5 min和14 min,2 h抗折强度和抗压强度分别为3.40 MPa和9.23 MPa,绝干抗折强度和抗压强度分别为6.70 MPa和21.82 MPa,满足GB/T 9776—2022《建筑石膏》3.0等级要求。相比空白组,2 h抗折强度提升了26%,2h抗压强度提高了40%。

关键词: 脱硫石膏, 建筑石膏, 硫酸铝钾, 煅烧

Abstract:

To solve the problem of low utilization rate of flue gas desulphurization gypsum(FGD gypsum) and improve its added-value utilization,calcined gypsum was prepared by calcining FGD gypsum added with potassium aluminum sulfate(KAS,mass ratio of 0,0.3%,0.6%,1.0%) at atmospheric pressure.The effects of calcination temperature and KAS content on the properties and the morphology of calcined gypsum were mainly studied.The results showed that the proper calcination temperature could improve the properties of calcined gypsum.However,excessive temperature could generate more cracks on the surface of calcined gypsum,and the properties were subsequently decreased.The addition of appropriate amount of KAS not only improved the crystallinity of calcined gypsum,but also promoted the growth of new phase dihydrate gypsum(DH) along the b-axis after hydration,delayed the growth along the c-axis,and significantly reduced the length-diameter ratio of DH crystals,which could promote the densification of gypsum sclerotium,resulting in the increase of strength.As 0.3% KAS was added into FGD gypsum and calcined at 170 ℃ for 2 h,the performance of the prepared calcined gypsum was the best.The initial and final setting time was 11.5 min and 14 min,respectively,the 2 h flexural and compressive strength were 3.40 MPa and 9.23 MPa,respectively,and the dried flexural and compressive strengths were 6.70 MPa and 21.82 MPa,respectively,which met the 3.0 grade requirements of the GB/T 9776—2022 “Calcined Gypsum”.Compared with the blank group,the 2 h flexural strength was increased by 26% and the 2 h compressive strength was increased by 40%.

Key words: FGD gypsum, calcined gypsum, potassium aluminum sulfate, calcination

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