为解决氨碱法煅烧工段中的粉碱和二氧化碳过剩问题，并探究纯碱和二氧化碳反应结晶过程的机理，以纯碱和二氧化碳为研究对象，探究Na₂CO₃溶液的浓度、CO₂的流量和反应结晶温度对反应和结晶过程的影响规律，采用拉曼光谱仪在线监测Na₂CO₃和NaHCO₃特征峰强度随反应结晶时间的变化趋势，通过标准曲线回归并结合相图分析，确定了反应体系点的变化路径、反应速率、成核速率和结晶速率。纯碱和二氧化碳的反应结晶分为3个阶段：纯碱和二氧化碳的反应阶段、碳酸氢钠的成核阶段和生长阶段，Na₂CO₃和CO₂的最大反应速率为0.450 mol/（kg·min），NaHCO₃的结晶（包括成核和生长过程）速率为0.083 mol/（kg·min），NaHCO₃反应结晶的3个阶段中反应速率最大、结晶速率最小，说明碳酸氢钠的结晶是该过程的速率控制步骤。随CO₂流量和温度的升高，反应速率、成核速率和结晶速率均增大。随碱液浓度的增加，纯碱与二氧化碳反应速率及NaHCO₃的结晶速率均降低，而NaHCO₃的成核速率随之提高，体系点的变化路径发生较大变化，最终分别进入NaHCO₃的单一固相结晶区、NaHCO₃和倍半碳酸钠的共析区，以及NaHCO₃、倍半碳酸钠和一水碳酸钠的共析区。

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.