In the process of preparing ammonium metatungstate by tungstic acid method, the following measures can be taken to control pH value to ensure product quality and process stability:
- Control method of pH value
Initial pH setting
After tungstic acid is dissolved in ammonia, the initial pH value should be set at about 8, which is favorable for the reaction between tungstic acid and ammonia to generate ammonium tungstate.
Acetic acid adjustment
Add acetic acid when the solution is boiling. Acetic acid reacts with ammonium ions in ammonia to form ammonium acetate, thus lowering the pH of the solution.
Acetic acid should be added slowly and stirred thoroughly to avoid localized low pH.
Fine-tuning with dilute nitric acid
After adding acetic acid, use dilute nitric acid to further fine-tune the pH value to the range of 2 to 4.
The addition of dilute nitric acid also needs to be slow, stirring while adding, real-time monitoring of pH changes.
Second, the importance of pH control
Product quality
Too low pH value may lead to the decomposition of ammonium metatungstate, while too high pH value may introduce impurities and affect the purity of the product.
Strictly controlling the pH value in the range of 2~4 helps to ensure the stable formation of ammonium metatungstate and the purity of the product.
Process stability
Stable control of pH value is crucial for the stability of the whole preparation process.
Stable pH value can reduce process fluctuations, improve production efficiency and reduce production costs.
III. Strategies for controlling pH value
Real-time monitoring
Use a pH meter to monitor the pH changes in the solution in real time so that timely adjustments can be made.
Slow addition
When adding acetic acid and dilute nitric acid, add them slowly to avoid localized pH value being too high or too low.
Stir well
When adding adjusting agents, stir the solution thoroughly to ensure that the pH in the solution is evenly distributed.
Standardized operation
Formulate standardized operating procedures to clarify the steps and methods of pH adjustment to ensure the consistency and stability of each production.
Through the above measures, the pH value during the preparation of ammonium metatungstate by tungstic acid method can be effectively controlled, so as to improve product quality and process stability.
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
