The process of producing ammonium metatungstate hydrate by ion exchange method can be clearly summarized in the following steps:
Preparation of raw materials
Take ammonium paratungstate as the main raw material, make sure its purity and quantity meet the production demand.
Heating and Conversion
Heat the ammonium paratungstate at a temperature of 130 to 140°C for 1 to 8 hours.
Convert the heated product into slurry to facilitate the subsequent reaction.
Boiling
The product that was blended into a slurry was boiled at a temperature of 80 to 100°C for 2 to 6 hours.
This step is to further promote the reaction to produce ammonium metatungstate solution.
Control of acidity of effluent
The acidity of the effluent needs to be controlled to a pH of about 3.5.
The acidity control is essential for the subsequent reaction to ensure that the ammonium tungstate can be converted into a stable ammonium metatungstate solution.
Cooking
The ammonium metatungstate solution is boiled at 98°C for 5 hours.
This step ensures the complete conversion of ammonium tungstate to ammonium metatungstate.
Evaporation and concentration
The boiled ammonium metatungstate solution is evaporated and concentrated to remove excess water and increase the concentration of the solution.
Crystallization by cooling or spray drying
Cooling crystallization
By lowering the temperature, the ammonium metatungstate in the solution precipitates into crystals.
Spray drying
Spray the solution into tiny droplets and dry it quickly into powder under high temperature.
Choose the appropriate crystallization or drying method according to the production demand.
Filtration Separation and Drying
If the cooling crystallization method is used, the crystals need to be filtered and separated to remove the impurities in the solution.
Then the separated crystals are dried to get dry ammonium metatungstate hydrate.
Product Inspection and Packing
The quality inspection of the produced ammonium metatungstate hydrate is carried out to ensure that it meets the relevant standards and requirements.
After passing the inspection, the product is packed for storage and transportation.
Resin regeneration (optional step)
If ion exchange resin is used for production, the resin saturated with NH4+ needs to be regenerated by hydrochloric acid solution for recycling at the end of production.
Ammonium metatungstate hydrate can be efficiently prepared by the above process. The ion exchange method has a wide application prospect in the field of ammonium metatungstate production due to the advantages of simple process, convenient control, being able to avoid the formation of APT and not bringing in new pollutants.
More details of ammonium metatungstate product, please visit website: http://ammonium-metatungstate.com/
Please contact CHINATUNGSTEN for inquiry and order of ammonium metatungstate:
Email: sales@chinatungsten.com
Tel.: 86 592 5129595
