熔盐法制备珠光颜料用片状氧化铝

Preparation of lamellar aluminium oxide through molten salt synthesis

以Al2（SO4）3.18H2O为铝盐来源,采用不同的熔盐体系（包括NaCl-KCl、Na2SO4-K2SO4、K2SO4、NaCl、NaNO3、NaF）,加入少量TiO2、Na3PO4等作助溶剂,用液相溶胶-凝胶法制备前驱体Al（OH）3,煅烧后得到片状氧化铝。通过光学显微镜、粒度分析仪和X射线衍射仪观察和分析氧化铝的形貌、粒度和物相,研究熔盐体系、煅烧温度和添加剂对氧化铝粉体粒径及形貌的影响。结果表明：以复合硫酸盐（Na2SO4-K2SO4）为助溶剂体系,同时添加3.0%磷酸钠和1.0%的二氧化钛为辅助添加剂,在1 200℃下煅烧5 h,可获得形貌完好、表面光滑、流线性好、具有高分散性和珠光效应的六角片状α-Al2O3粉体,粉体平均粒径为10.613μm,厚度150~300 nm,径厚比为25~40。

Lamellar aluminium oxide single crystal particle were successfully calcinated Al（OH）3 as precursor,which was produced by sol-gel method using Al2（SO4）3·18H2O as raw material and adding small-amount of TiO2,Na3PO4,K2SO4,etc,as flux.The morphology,particle size and phase composition of aluminium oxide powder were analyzed by optical microscope,granulometer and XRD.The effects of molten salt system,calcinate temperature and additives on the particle size and morphology of aluminium oxide powder were studied.It is found that hexagonal lamellate α-Al2O3 powder with perfect morphology,smooth surface,good dispersion property,good plarlitic effect,particle size of 4~15 μm（average of 10.613 μm）,thickness of about 150~300 nm and aspect ratio of 25~40 can be obtained,using composite（Na2SO4-K2SO4） as flux system,adding 3.0% sodium phosphate and 1.0% TiO2 as additives,and calcinated at 1 200 ℃ for 5 h.