二氧化碳鼓泡碳化法制备碳酸钙的研究

以氯化钙为钙源，硝酸锌为添加剂，与二氧化碳鼓泡碳化反应制备碳酸钙，探究了各因素对鼓泡碳化法制备碳酸钙的影响，运用单一因素变量法对鼓泡碳化法做了优化。利用XRD，SEM研究了氨水含量、CO₂流量、碳化温度、碳化时间、硝酸锌添加量对碳酸钙形貌、结构的影响及机制。结果表明，当氨水体积分数为2.4%、CO₂流量为180 mL/min、碳化时间为30 min、碳化温度为30 ℃、硝酸锌添加量为0.002 mol时，可制得形貌为球形，且为单一晶型、结晶完善的碳酸钙颗粒。并设计了正反滴实验，验证并完整提出了CaCl₂-CO₂-CaCO₃体系中碳化反应作用机理。

Study on preparation of calcium carbonate by carbon dioxide bubbling carbonation

Calcium carbonate was prepared by carbon dioxide bubbling carbonation reaction with calcium chloride as the source of calcium and zinc nitrate as the additive.The influences of various factors on the preparation of calcium carbonate by bubbling carbonation were explored and the process was optimized by the single factor variable method.The effects and mechanisms of operation parameters，such as ammonia amount，CO₂ flow rate，carbonization temperature，carbonization time，and zinc nitrate amount on the morphology and structure of the calcium carbonate were investigated by XRD and SEM.Under the optimum condition as the ammonia volume fraction of 2.4%，CO₂ flow rate of 180 mL/min，carbonization time of 30 min，carbonization temperature at 30 ℃，and zinc nitrate of 0.002 mol，spherical calcium carbonate particles with well single crystal form could be prepared.Possible formation mechanism of calcium carbonate in the CaCl₂-CO₂-CaCO₃ system was proposed and confirmed by designed positive-negative titration experiment.