
Fine yellow tungsten oxide or fine tungsten trioxide is prepared by using double salt method. The finer the granular of yellow tungsten oxide is, the smaller the corresponding apparent density is. Fine WO3 is also produced by the reaction between artificial scheelite and hydrochloric acid (HCL). By using double salt method to produce fine tungsten trioxide, white amorphous gel tungstic acid will be formed first if the double salt and HCL react under cold conditions. And the greater the actual…