结晶-水热法制备六角片状氢氧化镁  

Preparation of hexagonal magnesium hydroxide flake by a crystallization-hydrothermal method

作　　者：吴易梅 孙玉柱[1,2] 路贵民 宋兴福[1] 于建国[1] WU Yi-mei;SUN Yu-zhu;LU Gui-min;SONG Xing-fu;YU Jian-guo(National Engineering Research Center for Integrated Utilization of Salt Lake Resources,East China University of Science and Technology,Shanghai 200237,China;Shanghai Institute of Pollution Control and Ecological Security,Shanghai 200092,China)

机构地区：[1]华东理工大学国家盐湖资源综合利用工程技术研究中心,上海200237 [2]上海污染控制与生态安全研究院,上海200092

出　　处：《高校化学工程学报》2019年第2期425-434,共10页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(U1607112);国家重点研发计划(2016YFC0401203);上海市优秀学术/技术带头人计划资助(18XD1424600)

摘　　要：针对常温合成的氢氧化镁(MH)易团聚,分散性差的问题,提出结晶-水热法制备分散性良好的六角片状氢氧化镁,确定了制备MH的最优工艺条件是以12 moL×L^(-1) NaOH为水热矿化剂,7%固含量的MH料浆为前驱体在170 ℃下水热5 h。结果表明制备的MH纯度达99.66%,白度达97.66,比表面积为3.57 m^2×g^(-1),平均一次粒径为0.69μm,颗粒厚度为185nm,(101)面微观应变为2.30×10^(-3),符合一级阻燃型氢氧化镁的标准。水热后的水热矿化剂,可以作为制备MH前驱体的沉淀剂;MH反应得到的NaCl滤液既可作为反应过程的底衬液,又能通过电解生产NaOH,实现了资源的循环利用。Magnesium hydroxide (MH) synthesized at room temperature tends to agglomerate with poor dispersity. A crystallization-hydrothermal method was proposed in this study to prepare hexagonal magnesium hydroxide flake to solve this problem. The optimum conditions for preparing MH were 12 moL·L^-1 NaOH as hydrothermal mineralizer and 7% MH slurry as precursor at 170 ℃ for 5 h. The results show that MH prepared has high quality with purity = 99.66%, whiteness= 97.66, specific surface area =3.57 m2·g^-1, average primary particle diameter = 0.69 μm, particle thickness = 185 nm and microscopic strain of the (101) plane= 2.30×10^-3, which meets the requirements of the first-grade flame retardant magnesium hydroxide. In addition, the hydrothermal mineralizer of MH can be reused as the reactant for the crystallization of MH precursors, and the NaCl filtrate obtained at the reactive crystallization stage can be reused as the solvent for MH preparation as well as NaOH production by electrolysis, which realizes resource recycling.

关 键 词：氢氧化镁 水热改性 分散性 六角片状 阻燃 

分 类 号：TQ132.2[化学工程—无机化工]