α-Al<sub>2</sub>O<sub>3</sub> Flake Pink Powder Synthesized by Molten Salt Method

In the paper, the flaky alumina was synthesized using Na2SO4-K2SO4 as flux by the molten salt method. The mole ratio of molten salt to alumina, temperature of synthesis and the amount of Cr3+ were investigated. The size of flake alumina was analyzed by laser sizer, the phases of the reaction products and the microstructures at different Cr3+ doping content was ascertained by XRD and the surface of flake alumina was observed by SEM. The alumina with two-dimensional planar structure, a large aspect ratio and adapting to preparation of pearlescent pigment was synthesized under the mole ratio of molten salt to alumina between 4 to 5 , the synthesis temperature about 1200°C, the heat preservation time in 4h and the mole amount of Cr2O3 about 2%.