Ammonium paratungstate has a great influence on the performance of nano blue tungsten oxide for transparent thermal insulation film. And the physical properties of nano grain size blue tungsten oxide powder have a great effect on the properties of tungsten powder and tungsten carbide powder. Therefore, special treatment of ammonium paratungstate is needed for preparing high quality tungsten carbide powder. The special treatment is mainly conducted before or after calcination of ammonium paratungstate.
Some scholars have carried out related experiments on this process and found that after special treatment of ammonium paratungstate, the performance of each grade of blue tungsten oxide changes regularly. The coarse grain size blue tungsten oxide powder and medium grain size blue tungsten oxide powder has the characteristics of larger surface area, higher bulk density, better uniformity, more regular particle shape and rich surface cracks than that of blue tungsten oxide powder of finer grain size.
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