共沉淀法制备镁铝双金属氢氧化物及表征

The preparation of double hydroxides of Mg - Al by Co - precipitation method and its characterization

采用共沉淀法以氯化铝、氯化镁、氢氧化钠及碳酸钠为原料,制备镁铝双金属氢氧化物,控制投料的镁铝比,陈化结晶时间和体系pH值,并用XRD,SEM和TGA对产物进行表征。实验结果表明:陈化结晶有利于晶体的生长和层状结构出现,体系的pH值为10.5时,会伴有Mg(OH)2杂质形成。在投料的镁铝比为3:1,陈化时间2h,pH为12时,制备出产物的结晶度好,层状结构清晰。

Double hydroxide of Mg -A1 was prepared by Co -precipitation method which aluminum chloride, magnesium chloride, sodium hydroxide and sodium carbonate were used as raw materials. In the process, control ratio of Mg to Al,different crystallization time and pH value of the system was dis- cussed, and were characterized by XRD, SEbl and TGA. The results showed that the crystallization time was conducive to the improvement of product crys- tallinity. There existed big（OH） z when pH value was 10.5. When the ratio Mg to A1 was 3：1, the crystallization time was 2h, pH value was 12, there was a great degree of crystallinity, clear the layered structure for the product.