Using blue tungsten oxide producing tungsten powder is generally taken the ammonium paratungstate or tungsten trioxide as raw material by weak hydrogen reduction. Blue tungsten oxide particle size is not a important factors in determining the tungsten powder particle size. The hydrogen reduction process of tungsten blue is the ultimate effect in determining tungsten powder particle size. Different reduction process parameters of blue tungsten oxide hydrogen reduction method will lead to different tungsten powder particle size and specific surface area. Because in the whole process of the blue tungsten to tungsten is chemical vapor migration, so the intermediate phase can form a relatively complete small faceted surface crystals.
Crystal formation and size depends on the speed of the water vapor formed and the speed of discharged from the difference material layer. So the water vapor concentration has a significant impact on the tungsten powder particle size. It is shown that when temperature lower than 600 ℃ and leading in small humidity hydrogen make reduction reaction, it will producing finer tungsten powder. Therefore, when using hydrogen reduction of blue tungsten oxide producing fine tungsten powder should be strictly controlled reduction process conditions.