碱式氯化镁烧结法制备氧化镁晶须的工艺研究

Studies on the Technology of Preparing Magnesium Oxide Whiskers wih Basic Magnesium Chloride by Sintering Method

以氯化镁和氢氧化钠为原料,通过前驱体烧结法制备氧化镁晶须。首先以氯化镁和氢氧化钠为原料合成了前驱体碱式氯化镁晶须,接着将碱式氯化镁焙烧成氧化镁晶须。探讨了各个工艺条件对产物的影响,探索出最佳的工艺条件:氯化镁溶液的浓度为3 mol/L,氯化镁和氢氧化钠的摩尔比为5∶1,陈化时间72 h,陈化温度50℃。在此条件下制得了前驱物碱式氯化镁晶须,将碱式氯化镁晶须焙烧,控制升温速率在5℃/min,采取分段升温方式升温至900℃,灼烧时间6 h,即可制得氧化镁晶须。所得的氧化镁晶须表面光滑,直径分布均匀,结晶良好,产率达80%以上。

MgO whiskers were synthesized from MgCl2 and NaOH as raw materials by sintering of the precursor. The preparation process consists of the synthesis of a precursor called basic magnesium chloride whiskers and the heat treatment of the synthesized whiskers. The precursor whiskers were prepared by MgCl： and NaOH as raw matcrisls. The influence of each condition to the products was discussed and the best conditions were found as follows the magnesium chloride solution concentration is 3 mol/L, the mole ratio of magnesium chloride to sodium hydroxide is 5 ： 1, the ripening time is 72 h, the ripening temperature is 50 ℃. The basic magnesium chloride whiskers were prepared under these conditions. Then the basic magnesium chloride whiskers were calcihated under the speed of elevated temperature in 5 ℃/min until the temperature raised to 900 ℃ by separate steps. After calcining six hours the magnesium oxide whishers were prepared. MgO whiskers obtained were possessed of smooth surface, uniform size distribution, well crystalline, and its productivity is more than 80%.