碳酸氢铵沉淀法制备球形氧化钪

Preparation of Spherical Scandium Oxide Powders by Ammonium Bicarbonate Precipitation

摘要:

研究了碳酸氢铵沉淀法制备球形氧化钪粉的方法。在溶液中以ScCl₃·XH₂O为前驱体制备含钪的碳酸盐。研究了反应温度、沉淀剂量和搅拌速度对钪回收率的影响。通过粉末X射线衍射和激光粒子测定表征了pH值对含钪碳酸盐晶体结构和粒径的影响。结果表明，随着反应pH值的增大，含钪碳酸盐的结构由非晶结构变为结晶结构，初始变化pH值约为6时，氧化钪的晶体结构为立方结构。同时，在一定条件下，可以获得3.756?103.8 μm尺寸的钪沉积物颗粒。当pH值为7时，钪的D₅₀为6.634 μm。含钪碳酸盐被用作制备氧化钪的前体。TG-DTA结果表明，碳酸盐的分解温度趋于600 ℃左右。基于XRD和IR分析，可以得出，当煅烧温度为1000 ℃时，获得相对纯净的氧化钪粉体材料。同时，采用激光粒度分析仪、BET和SEM-EDS对所得氧化钪粉末进行表征。球形氧化钪粉末的微晶尺寸小于10 μm，表面积约为373.952 m²/g。微观结构非常均匀，呈球形结构。

Abstract:

The preparation of spherical scandium oxide powders by ammonium bicarbonate precipitation was investigated. The carbonate containing scandium was prepared in the solution with ScCl₃·XH₂O as precursor. The effect of reaction temperature, amount of precipitant and stirring speed on the recovery of scandium was discussed. The effect of pH on the crystalline structure and particle size of carbonate containing scandium was characterized by the powder X-ray diffraction and laser particle sizer. Results demonstrate that the structure of carbonate containing scandium changes from non-crystalline structure to crystalline structure with increasing the reaction pH value. It indicates that when the initial change pH value is about 6, the crystalline structure of scandium oxide is cubic structure. Meanwhile, scandium sediment particles with 3.756?103.8 μm in size can be obtained in a certain condition, depending on the pH value,. When the feasible pH value is 7, the D₅₀ of scandium sediment can be 6.634 μm. The carbonate containing scandium is used as a precursor for the preparation of scandium oxide. The TG-DTA result indicates that the decomposition temperature of the carbonate tends to about 600 ℃. Based on the XRD and IR analysis, it can be concluded that the appropriate calcination temperature for obtained relatively pure scandium oxide is 1000 ℃. Meanwhile, the obtained scandium oxide powders were characterized by the laser particle size analyzer, BET and SEM-EDS. The crystallite size of spherical scandium oxide powders is less than 10 μm with a surface area of about 373.952 m²/g. The microstructure is very homogeneous with spherical structure.