晶种法制备氢氧化镁阻燃剂粉体

Study on the Preparation of Magnesium Hydroxide Powder in Seeding Method

以卤水为原料,以氢氧化钠为沉淀剂,采用加入晶种两步合成法制备出类似立方状的氢氧化镁粉体颗粒。通过SEM,XRD和粒度分布考察了不同水热时间氢氧化镁粒子的形貌、大小、(101)面内应变和粒度分布的变化。研究发现采用加入晶种两步合成法,氢氧化镁的生长速度明显快于未加入晶种的氢氧化镁的生长速度,且其分散性更好,过滤时间更短。前6 h氢氧化镁为片状,24 h后其宽厚比接近1;(101)面内应变的增加主要集中在6 h～12 h时间段内,12 h后增加速度明显变缓。

With brine as raw materials and sodium hydroxide as precipitant,nearly cubic-shaped crystal of magnesium hydroxide was synthesized by two-step reaction of Mg（OH） 2 preparation with inoculating seed as additions.The particle size,morphology,microscopic internal strain on plane（101）,and particle distribution were characterized through scanning electron microscopy（SEM）,X-ray diffraction（XRD） and size distribution,with focus on the influence of hydrothermal time.The two-step reaction of Mg（OH） 2 preparation with inoculation seed as additions can increase the growth rate of magnesium hydroxide,decrease the filtering time and make magnesium hydroxide have a better dispersion.In the study,it is easy to get lamrllar magnesium hydroxide in the firstly six hours,flakiness ratio get close to one after 24 h.Increasing of mircosscopic internal strain concentrated in 6 h to 12 h period,then it slack-off.