The process of preparing tungsten trioxide from ammonium metatungstate can be realized through several steps, and the following is the detailed preparation process:
Starting material
The starting material is ammonium metatungstate, which can usually be produced from ammonium tungstate solution or sodium tungstate solution by solvent extraction, ion exchange and other methods.
Heating treatment
Ammonium metatungstate is subjected to heating treatment. In this process, ammonium metatungstate loses all of its ammonia and water of crystallization at a certain temperature (e.g. above 600°C).
Cooling and crystallization
After heating, the substance is allowed to cool naturally and crystallize. This step helps to form a stable crystal structure.
Drying
The cooled product is dried thoroughly to ensure that the water is completely removed. After drying, the substance is converted to yellow tungsten trioxide.
Precautions
Temperature control is critical throughout the preparation process. It is necessary to ensure that the heating temperature is high enough to induce complete decomposition of the ammonium metatungstate, but it is also important to avoid excessive temperatures that could lead to deterioration of the product or uncontrolled reaction.
In addition, the drying step needs to be carried out sufficiently to remove possible residual moisture and ensure the purity of the final product.
Other Preparation Methods:
In addition to the direct heating method described above, tungsten trioxide can also be prepared by hydrothermal methods. This method involves dissolving ammonium metatungstate in ultrapure water and adding additives such as polyethylene glycol and nitric acid solution, followed by a hydrothermal reaction and subsequent steps such as drying and calcination.
In short, the process of preparing tungsten trioxide from ammonium metatungstate mainly includes the steps of heating treatment, cooling crystallization and drying. By controlling the temperature, adding the right amount of additives and adequate drying treatment, it can ensure the final high purity of tungsten trioxide products.
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
