硅铝比及固体反应物浓度对合成Mn-Kaolinite的影响

Effect of Si-Al Ratio and Solid Reactant Concentration on the Synthesis of Mn-Kaolinite

本文以硅酸、Al(NO3)3·9H2O、MnCO3、KOH为原料,采用水热法合成了具有良好晶格结构的含Mn高岭石。利用XRD、SEM以及EDS等测试方法对所合成的高岭石进行了表征,研究了在碱性环境中及硅铝比分别为1/3(富铝)、1/1、3/1(富硅)条件下固体反应物浓度对合成高岭石产量、结构和形态的影响,并探讨了Mn离子在MnKaolinite形成过程中的作用机理。结果表明,在硅铝比为1/1、固体反应物浓度为0.3/50条件下合成的MnKaolinite品质最优,呈薄片状。随着固体反应物浓度升高,所得产物的产率降低,同时出现针状Mn-Kaolinite。此外,还在反应时间为3小时条件下成功合成了高岭石,补充完善了合成方法。

Mn-kaolinite with a high degree of crystallinity has been synthesized via the hydrothermal method,using reactants including silicic acid,Al（ NO3）3·9H2O,MnCO3 and KOH. The synthesized kaolinite was characterized by XRD,SEM and EDS. We investigated,in an alkaline environment and under the conditions of silicon-aluminum ratio 1 /3（ aluminum-rich）,1 /1 and 3 /1（ silicon-rich）,respectively,the influence of solid reactant concentration on the morphology,structure and yields of kaolinite. The function of Mn ions to the formation of Mn-kaolinite has also been revealed. The experiments indicated that the beneficial conditions for kaolinite formation were as follow： silicon /aluminum ratio is 1 /1,solid reactant concentrations is 0. 3 /50 and in strong alkaline environment,which yielded sheet-shaped Mn-kaolinite. The product yield would decrease with increasing solid reactant concentrations,and needle-shaped Mn-Kaolinite would be produced. Furthermore, Kaolinite was synthesized successfully only in 3 h with low solid reactant concentrations.