菱镁矿制备高纯纳米氧化镁的实验研究

Preparation of high-purity nano-magnesium oxide from magnesite

以轻烧氧化镁粉、肥料级硫酸铵和工业级碳酸氢铵为原料,以A12+A17+N2为表面改性剂,采用液相沉淀法制备高纯纳米氧化镁粉体。通过单因素及正交实验得到制备高纯纳米氧化镁的最佳工艺条件:碳酸铵溶液与硫酸镁溶液的体积比为0.8∶1,反应时间为100 min,反应温度为70℃,碳酸铵溶液浓度为0.7 mol/L,硫酸镁溶液浓度为0.7 mol/L,复配表面改性剂的总加入量为0.1 mL,干燥温度为60℃,干燥时间为2 h;煅烧温度为600℃,煅烧时间为1.5 h。用粒度分析仪、XRD、SEM对最终产物高纯纳米氧化镁进行了表征。结果表明:产品粒径分布较窄,分散性良好,平均粒径在65 nm左右,纯度超过99.5%。工艺过程简单,产品质量稳定,适宜进行工业化生产。

Method of preparing high-purity nano-magnesium oxide by liquid precipitation method with light-burned magnesium oxide powder, fertilizer-grade ammonium sulfate, and industrial-grade ammonium bicarbonate as raw materials and A12 ＋ A17 ＋ N2 as surface modifier was introduced. Results of single factor and orthogonal experiments indicated the optimal process conditions were as follows： volume ratio of ammonium carbonate solution to magnesium sulfate solution was about 0.8：1 ,reaction time was 100 rain,reaction temperature was 70℃,concentration of ammonium carbonate solution was 0.7 mol/L, concentration of magnesium sulfate solution was 0.7 mol/L, total amount of complex surfactant was 0. 1 mL, precursor was dried at 60℃ for 2 h under vacuum and calcined in muffle furnace at 600℃ for 1.5 h to produce magnesium oxide. High-purity nano magnesium oxide were characterized by laser particle size analyzer, XRD, and SEM. Results indicated that the products were well dispersed with narrow size distribution and an average size of about 65 nm. Purity of magnesium oxide in products was over 99.5%. The simple process introduced can bring steady product quality and can be easily industrialized.