还原钨粉粒度特性的过程研究

Process research on particle size characteristics of reduced tungsten powder

钨粉的粒度、粒度分布和团聚等粒度特性,与后续产品性能关系密切。对黄钨和蓝钨这2种氧化钨进行氢还原,研究不同还原温度和时间下黄钨和蓝钨的还原过程,利用扫描电镜观察粉末的粒度分布和团聚状态,采用X射线衍射分析技术和氧指数来分析粉末的物相变化,采用比表面积表征宏观的粒度变化。研究结果表明,黄钨和蓝钨具有相同的反应速率和形貌变化过程,粒度、粒度分布和团聚等粉末粒度特性与还原温度关系密切:700℃以下低温还原后,钨粉颗粒大小均匀,容易产生团聚;800℃以上高温还原时,粉末团聚减少,颗粒大小不均。

The particle size,particle size distribution and agglomeration of tungsten powder are closely related to the properties of subsequent products.In this paper,the reduction process of yellow tungsten oxide and blue tungsten oxide is studied by static reduction test at different temperature and time.The particle size distribution and agglomeration state of the powder were analyzed by scanning electron microscope,the phase change process of the powder was analyzed by X-ray diffraction and oxygen index,and the macroscopic particle size change was characterized by specific surface area.The results show that yellow tungsten(WO3)and blue tungsten(WO2.9)have the same reaction rate and morphology change process.The particle size,particle size distribution and agglomeration are closely related to reduction temperature.After reduction at a low temperature below 700℃,the tungsten powder particles are uniform in size and easy to agglomerate.When the temperature is above 800℃,the agglomeration of the powder decreases and the particle size is uneven.