Ammonium Paratungstate Catalyze Preparation of Nanosize Titanium Dioxide with Tungsten

Nanosize titanium dioxide (TiO₂) refers to titanium dioxide with particles under 100 nm, mainly used in cosmetics, antimicrobial agents, etc.. Burning coal will generate nitric oxide and nitrogen dioxide and other nitrogen oxides which are poison to human body and plant. So denitrification has practical significance in the process of environmental protection. Denitrification catalyst is a substance that promotes the reducing agent reacting with titanium dioxide selectively at a certain temperature. Nanosize titanium dioxide with tungsten is a kind of catalyst for denitrification with a good performance. Preparation principle: Using metatitanic acid prepared by method of sulfuric acid as raw material, adding precursor of ammonium paratungstate and sulfate, delivery to rotary kiln for drying and roasting after stirring, and nanosize titanium dioxide with tungsten with high specific surface and surface acidic obtained.



Preparation process:
1. Remove impurities from partial acid by washing, and control ion concentrations of iron, alkali metal and all kinds of heavy metal below 100ppm;
2. Adding distilled water, configure partial acid slurry with content of TiO₂ less than 30%;
3. Adding precursor of sulfate into partial acid slurry after mixing;
4. Adding ammonium paratungstate at the proportion of WO₃ accounted 3~10% in the total quality of final titanium dioxide, stirring to mixing uniform;
5. Pressing leaching partial acid slurry by the diaphragm filter, and then send it to rotary kiln, raising the temperature up to 500-640℃ at rate of 20-60℃/h, nanosize titanium dioxide with tungsten which is special used as denitrification catalyst system.

Adding ammonium paratungstate into partial acid slurry, to get nanosize titanium dioxide with tungsten with higher activity, fluidity, honeycomb catalyst squeezed with smaller shrinkage rate for molding.

• < Prev
• Next >