The parameters that need to be controlled during the production of ammonium metatungstate hydrate mainly include the following:
Temperature control
In the heating and conversion step, the ammonium paratungstate needs to be heated and treated at a temperature of 130-140°C for 1-8 hours.
In the boiling process, the temperature should be controlled between 80 and 100°C and last for 2 to 6 hours.
In the boiling decomposition step, the temperature needs to reach 98°C and maintain for 5 hours.
pH control
The acidity of the effluent needs to be strictly controlled at a pH of about 3.5 to ensure that the ammonium tungstate can be converted into a stable ammonium metatungstate solution.
Reaction time
The heating and conversion process needs to last from 1 to 8 hours.
The boiling step has a reaction time of 2 to 6 hours.
The reaction time in the boiling step is 5 hours.
Solid-liquid ratio
The solid-liquid ratio is also a parameter to be controlled in the neutralization method or similar processes. For example, according to the ratio of ammonium sec-tungstate: nitric acid = 1:20, 3% to 5% dilute nitric acid is added to the ammonium sec-tungstate slurry to control the solid-liquid ratio of 1: (3 to 4).
Stirring speed
At all stages of the reaction, the stirring speed has an effect on the homogeneity and efficiency of the reaction. It is necessary to ensure that the stirring speed is moderate to promote the smooth progress of the reaction.
Degree of evaporation and concentration
In the evaporation and concentration step, the degree of evaporation needs to be controlled to achieve the desired concentration of ammonium metatungstate solution.
Crystallization and drying conditions
In cooling crystallization, the temperature and speed of crystallization need to be controlled to obtain the desired crystal form and size.
When spray drying, parameters such as droplet size of spray, drying temperature and wind speed need to be controlled to ensure drying effect and product quality.
Product Quality Inspection
After the production is completed, the products need to be inspected for quality, including purity, particle size, moisture and other indicators to ensure that the products meet the relevant standards and requirements.
The control of the above parameters is crucial for the production of ammonium metatungstate hydrate, which together determine the quality and yield of the product. Therefore, in the actual production process, it is necessary to strictly follow the operating procedures and process requirements to ensure that the parameters are controlled within the appropriate range.
More details of ammonium metatungstate product, please visit website: http://ammonium-metatungstate.com/
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Email: sales@chinatungsten.com
Tel.: 86 592 5129595
