Prepare Silicon Tungstate from Ammonium Paratungstate

There are large number types of tungsten heteropoly acid. A method for preparing silicon tungstate from ammonium paratungstate, the specific steps are as follows:
1. Conversion process: select ammonium paratungstate, heating to 90~100℃, stirred with a speed of 60~120r/min, adjusting pH value among 2~4, then ammonium metatungstate (AMT) obtained;
2. Mach silicon: adding silicate into the transformed AMT, then adding ammonia, and adjust pH value to 7-8, heated to 90~100℃ with stirring, reaction time for 2~4.5 hours, pH 9 ~ 14, ammonium silicon tungstate;
3. Cation exchange: reaction in exchange column, the rate is 30~100L/hour;
4. Evaporation and concentration: filter to remove the insoluble in solution when the specific gravity of organic solution is 2g/cm³; continue to evaporate to get silicon tungstate until it reaches 3g/cm³.

The advantages of that method are as following:
1. Reasonable process, good quality of the product, no pollution, and suitable for large scale industrial production especially;
2. With important promotion value;
3. A kind of environmental friendly green catalyst widely used in petrochemical, chemical catalysis and medicine field;
4. Laid the foundation about producing and developing heteropoly acid and salt centered with other elements.