碳酸铝铵热解法制备超细Al_2O_3

Preparing Ultrafine Alumina Powder by AACH Thermal Decomposition

以Al2(SO4)3与(NH4)2CO3为原料,采用液相沉淀法,制备出前驱物碳酸铝铵(AACH),并烧结得到Al2O3粉末。通过分析前驱物的热重曲线,确定了前驱物的高温分解过程;并结合对前驱物在不同烧结温度下所得产物XRD图谱的分析,确定了前驱物的高温相变过程为:AACH→AlOOH→Al2O3(无定型)→γ-Al2O3→θ-Al2O3→α-Al2O3。同时,干燥方式对超细Al2O3分散性的影响在本文中也进行了研究。

Ammonlum aluminum carbonate hydroxide （AACH） was synthesized as the precursor by the precipitation reaction of aluminum sulfate and ammonium carbonate. Then the precursor was agglomerated to get Al2O3 powder. The thermal decomposition reaction of the precursor was confirmed by analyzing the DTA/TGA curves. The DTA/TGA curves and XRD shown that the phase transformation of AACH in sintering process was： AACH →AIOOH→amorphous Al2O3→γ→Al2O3→θ→Al2O3→α→Al2O3. And the effect of drying method on the dispersity of ultrafine alumina was also discussed in this paper.