【摘要】 以硝酸锰、氢氧化钠、氨水为原料,采用水解氧化沉淀法制备了nm级Mn3O4粉体材料。通过正交试验优化反应条件得到尺寸分布均匀,团聚程度小,颗粒分散性强的nm级Mn3O4粉体。研究了制备过程中反应温度、pH值、搅拌速度、反应物浓度等因素对产物组成、晶体结构、晶粒尺寸、形貌及颗粒团聚程度的影响。采用激光粒度分析仪(LPSA)、X射线衍射仪(XRD)、扫描电镜(SEM)以及化学滴定实验对反应产物进行了分析表征。实验结果表明,采用水解氧化沉淀法制粉时,可得到纯度较高的Mn3O4,当工艺参数pH值为10、温度40℃、搅拌速度3000r/min,反应物摩尔浓度c(Mn(NO3)2)∶c(NaOH)∶c(NH4OH)=2.4∶4.8∶0.96时,材料二次颗粒团聚程度最弱,分散性最好,一次纳米颗粒尺寸最小。更多还原

【Abstract】 Using manganese nitrate,sodium hydroxide and ammonia as reactants,the nanometer Mn3O4 was prepared by a hydrolysis and oxidation precipitation method in a self-assembly tank reactor. The preparation of manganese hydroxide was significantly dependant on synthetic condition,such as the reaction temperature,pH,stirring speed,concentration of reactants,etc. and the optimized condition by orthogonal experiment method resulted in manganese oxide which has uniform particle size distribution,low second agglomeration degree and good dispersibity. The relations between synthetic conditions and material properties such as crystal structure,grain size,morphology and total manganese content were studied.The analysis and characterization of reaction products were carried out by scanning electronic microscopy (SEM),laser particle size analyzer (LPSA),X-ray diffraction (XRD) and chemistry titration. The results show that,by a hydrolysis and oxidation precipitation method,the optimum technological parameters are as follows:pH=10,the reaction temperature is at 40 ℃,stirring speed is 3 000 r/min,molar concentration of reactants c(Mn(NO3)2)∶c(NaOH)∶c(NH4OH)=2.4∶4.8∶0.96,and in thiscondition,the nano-powder have low second agglomeration degree,good dispersivity and small nano-particle size.更多还原