机械活化重质碳酸钙制备复合碳酸钙及其对溶液中的Cu^(2+)吸附性能

Preparation of calcium carbonate composite by mechanically activated of ground calcium carbonate and its adsorption properties on Cu^(2+)ions in solution

利用机械活化法对重质碳酸钙进行了纳米化表面改性,以聚丙烯酸钠和纳米碳酸钙为改性原料与重质碳酸钙进行混合研磨,成功制备了纳米碳酸钙包覆重质碳酸钙的复合钙,并考察了复合钙对溶液中的Cu^(2+)的吸附性能。研究结果如下:扫描电子显微镜和X射线衍射仪分析证实了纳米碳酸钙包覆在重质碳酸钙表面,傅里叶变换红外光谱分析表明复合碳酸钙表面羟基明显增加,比表面积分析表明复合碳酸钙的比表面积为20.5m^(2)/g,具有介孔结构。复合碳酸钙对Cu^(2+)的最大吸附量为65.5mg/g,去除率可达98%。吸附性能研究表明,复合碳酸钙对Cu^(2+)吸附动力学符合伪二阶动力学模型,等温吸附过程符合Langmuir-Freundich模型,证明吸附过程以离子交换反应为主,该过程为吸热反应。

The surface modification of ground calcium carbonate(GCC)was accomplished by mechanically activated of GCC,sodium polyacrylate and nano calcium carbonate together and the CaCO_(3)composite coated with nano calcium carbonate was applied to the adsorption of Cu^(2+)in solution.The adsorption properties were also investigated.The results showed that SEM and XRD analyses confirmed that the nano calcium carbonate was successfully coated on the surface of GCC.FTIR analysis found that the hydroxyl groups increased on the composite surface,and BET analysis indicated that the specific surface area of composite was 20.5m^(2)/g with a mesoporous structure.The maximum adsorption capacity of composite calcium carbonate for Cu^(2+)was 65.5mg/g and the removal rate could reach 98%.The absorption process studies revealed that the adsorption kinetics followed the pseudo-second-order kinetic model and the adsorption isotherms followed the Langmuir-Freundich model,proving that the adsorption was dominated by ions exchange and was exothermal.