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 (3): 55-59.doi: 10.19964/j.issn.1006-4990.2022-0289

• 研究与开发 • 上一篇    下一篇

海水体系碳酸钠水合物结晶形成过程研究及应用

巩学敏(), 张荣瑜, 李娜, 郝雅楠, 张千   

  1. 华北理工大学化工学院,河北 唐山 063210
  • 收稿日期:2022-05-12 出版日期:2023-03-10 发布日期:2023-03-17
  • 作者简介:巩学敏(1979— ),女,博士,副教授,主要从事水盐体系相平衡及资源综合利用等方面的研究;E-mail:gongxm1212@163.com
  • 基金资助:
    河北省自然科学基金面上项目(E2020209117)

Study on crystallization process of Na2CO3 hydrate in seawater system and its application

GONG Xuemin(), ZHANG Rongyu, LI Na, HAO Ya′nan, ZHANG Qian   

  1. College of Chemical Engineering,North China University of Science and Technology,Tangshan 063210,China
  • Received:2022-05-12 Online:2023-03-10 Published:2023-03-17

摘要:

海水淡化副产浓海水中含有大量的化学资源,将浓海水增浓精制可以得到高浓度的盐水,得到的高浓度盐水可以作为氨碱法纯碱生产的原料。采用等温法测定了0 ℃时Na2CO3-Na2SO4-NaCl-H2O四元体系相平衡溶解度数据,绘制了相图并对其进行了分析。研究表明,0 ℃时该体系生成1个等温共饱点和3个结晶区,其中Na2CO3·10H2O结晶区面积较大,可用于碳酸钠水合物法增浓海水的工艺研究。物料守恒计算得出,该技术可使浓海水增浓80.56%,浓缩后氯化钠的浓度为原浓海水的5.14倍。碳酸钠水合物法增浓盐水用于纯碱生产的原料,可以减少原有纯碱生产工艺的化盐过程,有利于实现副产浓海水利用的最大化。该技术为浓海水高效综合利用提供理论和数据支持。

关键词: 浓海水, 相平衡, 结晶, 碳酸钠, 水合物

Abstract:

Concentrated seawater,a by-product of seawater desalination,contains a large number of chemical resources.Concentrated brine can be obtained by thickening and refining,which can be used as raw material for soda ash production by ammonia-alkali process.The phase equilibrium solubility data of Na2CO3-Na2SO4-NaCl-H2O quaternary system at 0 ℃ was determined by isothermal method,and the phase diagram was drawn and analyzed.The results showed that at 0 ℃,there were 1 isothermal cosaturation point and 3 crystallization zones in the system,of which the area of Na2CO3·10H2O crystallization zone was large,which could be used for the process research of sodium carbonate hydrate method to enrich seawater.The calculations of the material balance showed that the technology could concentrate desalinated seawater by 80.56%,and the concentration of NaCl was 5.14 times of the original concentrated seawater.The use of sodium carbonate hydrate method to increase the concentration of brine as raw material for soda ash production could reduce the salinization process of the original process,help to maximize the utilization of by-product concentrated seawater,and provide theoretical and data support for the efficient and comprehensive utilization of concentrated seawater.

Key words: concentrated seawater, phase equilibrium, crystal, Na2CO3, hydrate

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