仲钨酸铵的制备及研究

Research and Preparation of Ammonium Paratungstate

通过对比蒸发法与在蒸发法中添加晶种和钨酸铵溶液制备的仲钨酸铵产品,结果表明后者制备的晶形更完整、颗粒较粗,且是纯度更高的5水仲钨酸铵。对产品进行了X射线衍射分析与热重分析,并探讨了仲钨酸铵成核机制、动力学过程。最后讨论了添加晶种和钨酸铵溶液对晶体形貌的影响。

Comparing the products which were prepared by evaporation and by adding seed crystal and solution of ammonium tungstate at the time of evaporation, we found that the latter was ammonium paratungstate containing 5 molecular of crystal water which was more integrate, thicker and purer. The products were detected by Xray diffraction analyses and thermogravimetric analyses, then crystallization mechanism and dynamical process of Ammonium Paratungstate were discussed. At last we analyzed the effect of adding seed crystal and solution of ammonium tungstate on crystal appearance.