CO_2释放对碳酸钙过饱和溶液析晶过程的影响

Influence of CO_2 Release on Process of Precipitation of Calcium Carbonate

建立了碳酸钙过饱和溶液析晶动力学过程的双参数测量系统 ,该系统可监测碳酸钙析晶速率 ,同时能实时计算CO2 释放速率 ,以用于定量研究溶液中CO2 气体向大气释放对碳酸钙过饱和溶液自发沉淀过程的影响 .研究结果表明 ,碳酸钙析晶过程不是一个孤立过程 ,而是伴随有CO2 气体向大气释放的过程 .这 2个过程彼此影响 :CO2气体的释放使溶液 pH上升 ,从而促使CaCO3 析出 ;而CaCO3 的析出改变了溶液中总碳浓度和总钙浓度的比值 ,从而改变了CO2 的析出速率 .实验获得的可重复的定量数据证实CO2 释放和CaCO3 析晶是不可分割的统一过程 .

Based on the chemistry equilibrium theory of calcium carbonate aqueous solution,the dual parameters measurement system was set up to study the kinetics of precipitation of calcium carbonate(CaCO_3),which can measure the rate of precipitation of CaCO_3 and calculate the rate of the release of carbonate dioxide(CO_2) to air simultaneously.The results show that the process of the precipitation of CaCO_3 is not isolated but accompanied with the process of the release of CO_2.These two processes are influenced by each other.The release of CO_2 will result in the increase of pH,and thereby enhance the precipitation of CaCO_3 and the precipitation of CaCO_3 will alter the ratio of the molar concentration of total calcium species to total carbon species,and thereby influence the rate of release of CO_2.The quantitative and repeatable experiment data reveal that the precipitation of CaCO_3 and the release of CO_2 are uniform and correlative.