Inorganic Chemicals Industry ›› 2025, Vol. 57 ›› Issue (10): 55-63.doi: 10.19964/j.issn.1006-4990.2024-0550

• Research & Development • Previous Articles     Next Articles

Study on reaction crystallization process of soda ash and carbon dioxide

ZHANG Menghan1(), DU Wei1, XU Quan2, CAO Jun2, TANG Na1()   

  1. 1. College of Chemical Engineering and Materials Science,Tianjin University of Science & Technology,Tianjin 300457,China
    2. Jiangsu Suyanjingshen Co. ,Ltd. ,Huai′an 223200,China
  • Received:2024-10-15 Online:2025-10-10 Published:2025-05-13
  • Contact: TANG Na E-mail:2289151500@qq.com;tjtangna@tust.edu.cn

Abstract:

This paper was aimed to address the problem of excess powder alkali and carbon dioxide in the calcination section of the ammonia-soda process and to explore the reaction and crystallization mechanism of sodium carbonate and carbon dioxide.Therefore,sodium carbonate and carbon dioxide were taken as the research objects to investigate the effect of the concentration of Na2CO3 solution,the flow rate of CO2,and the reaction crystallization temperature on the reaction and crystallization process.Raman spectrometer was used to monitor the changes in the intensity of characteristic peaks of Na2CO3 and NaHCO3 with reaction and crystallization time.Through standard curve regression and phase diagram analysis,the change path of the reaction system point,reaction rate,nucleation rate,and crystallization rate were determined.The reaction and crystallization of sodium carbonate and carbon dioxide could be divided into three stages:the reaction stage of sodium carbonate and carbon dioxide,the nucleation and growth stage of sodium bicarbonate.The maximum reaction rate of Na2CO3 and CO2 was 0.450 mol/(kg·min),and the crystallization rate(including nucleation and growth process) of NaHCO3 was 0.083 mol/(kg·min).The reaction rate was the fastest and the crystallization rate was the lowest in the three stages of the reaction and crystallization of sodium bicarbonate,indicating that the crystallization of sodium bicarbonate was the rate-controlling step of this process.With the increase of CO2 flow rate and temperature,the reaction rate,nucleation rate,and crystallization rate were all increased.With the increase of alkali solution concentration,the reaction rate of sodium carbonate and carbon dioxide and the crystallization rate of sodium bicarbonate were both decreased,while the nucleation rate of sodium bicarbonate increased,and the change path of the system point changed significantly.Eventually,they entered the single solid phase crystallization zone of sodium bicarbonate,the eutectic zone of sodium bicarbonate and sesquicarbonate,and the eutectic zone of sodium bicarbonate,sesquicarbonate and monohydrate sodium carbonate,respectively.

Key words: sodium carbonate, baking soda, reaction crystallization rate, in situ Raman, process phase diagram analysis

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