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仲鎢酸銨還原制備超粗球形鎢粉

Preparation of coarse and spherical tungsten powders by ammonium paratungstate

  • 摘要: 以鎢酸銨溶液為原料,加入含Li、Na和K堿金屬鹽的添加劑,在濕氫條件下還原制備粗晶球形鎢粉.研究了堿金屬鹽的種類、含量及還原時間對仲鎢酸銨粉末及鎢粉的影響.通過掃描電鏡、能譜儀、X射線衍射儀和檢驗分析篩對仲鎢酸銨及粗晶鎢粉的形貌、成分、物相組成及粒度分布進行表征.研究表明,采用鎢酸銨溶液為原料,添加劑(NaCl、KCl和Li2CO3)為3 g·L-1,在1000℃濕氫條件下還原180 min,可直接制備出流動性良好、近球形、晶粒發育完整且均勻的粗晶鎢粉.其平均粒徑達到67μm,最大粒徑可達150μm,最大松裝密度為13.41 g·cm-3,最佳流動性為每50 g粗晶鎢粉用時9 s.

     

    Abstract: Coarse and spherical tungsten powders were prepared by wet hydrogen reduction.Ammonium tungstate solutions with the additives of Li,Na and K alkali metal salts were used as raw materials.The effects of the type and content of the alkali metal salts as well as reduction time on the microstructure,chemical composition,phase composition, and particle size of ammonium paratungstate(APT) and coarse tungsten powders were investigated by scanning electronic microscopy,energy dispersive spectroscopy,X-ray diffraction,and test sieves.It is shown that ideal tungsten powders with good fluidity,sphericity,integrity and even distribution can be obtained by using the ammonium tungstate solution with 3 g·L-1 NaCl,KCl and Li2CO3 and reducing at 1000℃for 180 min in wet hydrogen atmosphere.The average particle size of the obtained tungsten powders is 67μm,the maximum particle size is 150μm,the biggest loose density is 13.41 g·cm-3,and the best powder flowability is 9 s for 50 g tungsten powders.

     

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