低品位菱镁矿制备纳米氧化镁的工艺优化研究

研究了低品位菱镁矿煅烧工艺优化及其对纳米氧化镁产品性能的影响问题.为了保证轻烧镁粉的活性和低品位菱镁矿的充分利用,通过调节煅烧温度和时间,发现低品位菱镁矿煅烧的适宜工艺条件为750℃煅烧1.5 h.以此法得到的轻烧镁粉为原料,配合工业级硫酸铵和碳酸氢铵以及自制的复配型表面活性剂,采用液相均匀沉淀法,制得平均粒径为60 nm的纳米氧化镁粉体,优选的沉淀反应条件为85℃下反应85 min,优选的前驱体煅烧工艺条件为550℃下煅烧1.5 h.利用激光粒度分析仪、XRD衍射仪及扫描电镜表征了产品性能,结果表明,本实验方法制得的纳米氧化镁粉体颗粒形状均匀,粒径分布窄,分散性良好.

Preparation Nanometer Magnesia from Low-grade Magnesite

Problems of optimizing calcining technology of low-grade magnesite and the influence on product properties of magnesia is focused on. To assure the activity of magnesia powder and make the most of low-grade magnesite, by adjusting calcinations temperature and time, the proper process condition is obtained at 750℃ for 1.5 h. By method of homogeneous precipitation, taking the caustic-burned magnesia powder, industrial grade ammonium sulfate and ammonium bicarbonate as raw materials and homemade compound type surfactants, nanometer magnesia power of average particle size of 60 nm is obtained. The optimal process conditions are as followings： Reaction at 85 ℃ for 85 rain, optimized precursor calcining process condition is at 550 ℃ for 1.5 h. The nano-magnesium oxide is characterized by laser particle size analyzer, XRD, and SEM. Results indicated that the products are well dispersed with narrow size distribution and an average size.