方解石制备碳酸钙晶须的影响因素及机理

以方解石矿石为原料,利用制备的重镁水(Mg(HCO₃)₂)及中间产物氯化钙制备文石型碳酸钙晶须,并采用SEM、XRD及EDS对产品进行表征。探究了重镁水与氯化钙反应过程中反应温度、反应时间、镁钙浓度比、重镁水浓度以及搅拌速度对碳酸钙晶须形貌的影响。通过单因素实验得出了最佳工艺条件:温度40 ℃、反应时间2 h、镁钙浓度比6∶1、重镁水浓度0.14 mol/L、搅拌速度150 r/min。在此条件下,制得了长度为40~65 μm、直径为0.6~1.5 μm、长径比为25~45的文石型碳酸钙晶须。

Influencing Factors and Mechanism of Calcium Carbonate Whiskers Prepared from Calcite

Calcite was used as raw material, the prepared heavy magnesium water (Mg(HCO₃)₂) and the intermediate product calcium chloride were used to prepare aragonite calcium carbonate whiskers, and the products were characterized by SEM, XRD and EDS. The effects of reaction temperature, reaction time, concentration ratio of magnesium to calcium, concentration of heavy magnesium water and stirring speed on the morphology of calcium carbonate whiskers during the reaction of heavy magnesium water and calcium chloride were explored. The best process conditions are obtained through single factor experiments: temperature of 40 ℃; reaction time of 2 h; magnesium-calcium concentration ratio of 6∶1; heavy magnesium water concentration of 0.14 mol/L; stirring speed of 150 r/min. Under these conditions, aragonite calcium carbonate whiskers with a length of 40~65 μm, a diameter of 0.6~1.5 μm, and an aspect ratio of 25~45 were prepared.