高剪切均质乳化法制备纳米氧化镁

Preparation of nanometer magnesium oxide under high shear homogeneous emulsification conditions

以硫酸镁和碳酸铵为原料,A1为活化剂,采用液相沉淀法配加高剪切均质乳化机制备了平均粒径为80nm的氧化镁。通过单因素和正交实验得到制备纳米氧化镁的最佳工艺条件为:碳酸铵溶液浓度0.75mol/L,硫酸镁溶液浓度0.75mol/L,碳酸铵与硫酸镁体积比0.8∶1,反应温度45℃,反应时间30min,乳化机转速10kr/min。干燥温度105℃,干燥时间1.5h,煅烧温度550℃,煅烧时间1h。用粒度分析仪、X-射线衍射仪(XRD)等手段对产物纳米氧化镁粒度分布和晶型结构进行了表征,结果表明:产品纯度较高,分散性良好,平均粒径为80nm,同时也可得到纳米级的前驱体碱式碳酸镁。此工艺流程简单,产品质量稳定,易于工业化生产。

The magnesium oxide with average particle size of 80 nm was prepared by liquid precipitation method and high shear homogeneous emulsification machine using magnesium sulfate, ammonium carbonate as raw materials and A1 as surface active agent. Experiments on single factor and orthogonal indicated the optimal process conditions were as follows., concentration of ammonium carbonate solution was 0. 75 mol/L, concentration of magnesium sulfate solution was 0.75 mol/L,volume ratio of ammonium carbonate solution to magnesium sulfate solution about 0.8 ： 1, reaction temperature 45 ℃ ,reaction time 30 min,the speed of emulsifying machine 10 kr/min. Precursor was dried at 60 ℃ for 1.5 h under vacuum and calcined in muffle furnace at 550 ℃ for 1 h to produce magnesium oxide. The size distribution, chemical structure and the crystallization properties.of nanometer magnesium oxide were characterized by laser particle size analyzer and XRD. Results indicated that the purity of products was high, the products were well dispersed and had a narrow distribution and an average size of about 80 nm. The nano-scale precursor basic magnesium carbonate was also obtained in this process. This process introduced is simple in flowsheet, steady in product quality and easy for commercialization.