氯化钙溶液制备沉淀碳酸钙的工艺研究

Study on Preparation of Precipitated Calcium Carbonate from Calcium Chloride

对采用氯化钙作为原料合成碳酸钙的工艺路线进行了探讨,主要研究了CO体积分数,通气速率、碳化起始温度和添加剂等对沉淀碳酸钙形貌的影响。发现由氯化钙为原料得到的碳酸钙其团聚较为严重,且沉降体积较低。以六偏磷酸钠为添加剂可以得到比颗粒较大且形状比较规整的球状沉淀碳酸钙,其球形颗粒尺寸在10μm左右,以柠檬酸为添加剂则得到尺寸在5μm以下的类球状颗粒团聚体,用磷酸作为添加剂可以得到尺寸在2~5μm左右的球形颗粒和尺寸在5μm以下的不规整球形颗粒团聚体。

The preparation process of precipitated calcium carbonate from calcium chloride was discussed.The focus was made on the influence of carbon dioxide concentration,carbona dioxide flow rate,carbonation temperature and additives on the morphology and size of precipitated calcium carbonate.It was found that calcium carbonate obtained from calcium chloride had serious agglomeration and low sedimentation volume.Regular spherical precipitated calcium carbonate could be obtained by adding sodium hexametaphosphate as additive,and the size was about 10 μm while spherical like aggregates could be obtained by adding citric acid as additive.When phosphoric acid was used as additves,the calcium carbonate obtained had two kinds of morphology.One is regular spherical and its size ranged from 2 μm to 5 μm,the other is spherical like aggregates and its size was less than 5 μm.