Nano grain size blue tungsten oxide for transparent thermal insulation window film can be used as a raw material for the preparation of tungsten powder, and the reduction method used includes static reduction method and dynamic reduction method, respectively. Therefore, some scholars have studied the thermodynamics and kinetics of industrial scale static reduction of BTO powder and found that at 750°C~1000°C, the hydrogen reduction of blue tungsten oxide has the following transformation phase: WO3→WO2.90→WO2.72→WO2→W.
The most volatile WO2(OH)2 compound is a major contributor to tungsten migration. Its concentration is controlled by the ratio of temperature to water/hydrogen concentration. Kinetic studies also pointed out the effect of powder layer thickness and hydrogen flow on W grain growth. The growth rate and growth of the W particles depend on the difference between the H2O formation rate and the rate at which H2O is removed from the layer. In dynamic reduction, it is consistent with static reduction in terms of thermodynamics; however, there is a significant difference in kinetics.
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