Ultrafine blue tungsten oxide is a blue powder with ultrafine grain size.
Blue Tungsten Oxide Calcination
The process of preparing blue tungsten oxide by using ammonium paratungstate (APT) as raw material in hydrogen (H2) atmosphere is as follows:
APT is placed in the high temperature zone of quartz glass tube. Control temperature, hydrogen flow rate and holding time to produce blue tungsten oxide.
To obtain blue tungsten oxide with more cracks and better uniformity, set the parameters as follows:
1. The temperature is controlled at the range of 400~500°C; The calcination time is 30~40 minutes; And the hydrogen flow rate is 1.5L/min.
2. The calcination temperature of reduction, the main parameter affecting the performance of blue tungsten oxide, is controlled at 40°C.
Compared with APT, the blue tungsten oxide has lost the property of hexagonal crystal, forming deep-fractured and loose grain morphology with finer grain size. The surface of blue tungsten oxide has a large number of cracks and star-shaped holes, and there is a phenomenon of fracture, also the particle size uniformity is better.
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