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 ›› 2023, Vol. 55 ›› Issue (11): 100-106.doi: 10.19964/j.issn.1006-4990.2023-0116

• 环境·健康·安全 • 上一篇    下一篇

常压Mg-Na复合盐溶液体系制备α-半水石膏

李云飞(), 刘蜀庆, 唐盛伟, 张涛()   

  1. 四川大学化学工程学院,四川 成都 610065
  • 收稿日期:2023-03-06 出版日期:2023-11-10 发布日期:2023-11-16
  • 通讯作者: 张涛(1978— ),男,博士,副教授,主要研究方向为固废资源化利用和生物质基材料;E-mail:zhangtao@scu.edu.cn
  • 作者简介:李云飞(1990— ),女,硕士生;E-mail:13550719659@163.com
  • 基金资助:
    国家重点研发计划“固废资源化”重点专项(2019YFC1905800)

Preparation of α-hemihydrate gypsum in Mg-Na mixed salt solution system under atmospheric pressure

LI Yunfei(), LIU Shuqing, TANG Shengwei, ZHANG Tao()   

  1. School of Chemical Engineering,Sichuan University,Chengdu 610065,China
  • Received:2023-03-06 Published:2023-11-10 Online:2023-11-16

摘要:

盐溶液的种类和浓度是常压盐溶液法制备α-半水石膏的关键因素。以Mg(NO32为主体,考察了Mg(NO32-NaCl、Mg(NO32-Na2SO4和Mg(NO32-NaNO3 3种复合盐溶液体系中二水石膏向α-半水石膏转晶的过程,研究了Mg(NO32-NaCl体系中盐溶液浓度、转晶剂类型和用量对转晶速率和晶体形貌的影响。结果表明:在Mg(NO32-1%NaCl复合盐体系中4 h内将二水石膏全部转化为α-半水石膏的最低Mg(NO32质量分数为27%;随着Mg(NO32质量分数从27%增加至36%,溶液的过饱和度增大,二水石膏的转晶速率升高,诱导期从90 min减少至20 min;加入DL-苹果酸、顺丁烯二酸和3-硝基邻苯二甲酸转晶剂后,二水石膏转晶速率降低,产物长径比减小;在DL-苹果酸质量分数为1%条件下,α-半水石膏绝干抗压强度为21.74 MPa。

关键词: α-半水石膏, 常压盐溶液法, 转晶剂, 晶体形貌, 力学性能

Abstract:

The species and concentration of salt solution are the key factors of the preparation process of α-hemihydrate gypsum in the atmospheric salt solution method.With Mg(NO32 as main composition,three kinds of mixed salt solution,including Mg(NO32-NaCl、Mg(NO32-Na2SO4 and Mg(NO32-NaNO3,were employed to investigate the crystal transformation from dihydrate gypsum to α-hemihydrate gypsum,and the effects of the concentration of mixed salts,crystal modifier type and dosage on the transformation rate of dihydrate gypsum and crystal morphology were studied in the Mg(NO32-NaCl solution.The results showed that in the mixed salt solution of Mg(NO32-1%NaCl,the minimum Mg(NO32 mass fraction for the complete conversion of gypsum dihydrate to gypsum hemihydrate within 4 h was 27%.As the mass fraction of Mg(NO32 increasing from 27% to 36%,the supersaturation of the solution and transformation rate of dihydrate gypsum were increased,and the induction period was decreased from 90 min to 20 min.Using DL-malic acid,maleic acid and 3-nitrophthalic acid as crystal modifiers,the transformation rate of dihydrate gypsum was decreased and the aspect ratio was reduced.When the mass fraction of DL-malic acid was 1%,the absolute dry compressive strength of the α-hemihydrate gypsum was 21.74 MPa.

Key words: α-hemihydrate gypsum, atmospheric salt solution method, crystal modifier, crystal morphology, mechanical property

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