1. Determination of Sodium Hydroxide
Over a period of two months, two reagents were tested in parallel while analyzing the sample for the customer.The analysis results of the lower Sodium Hydroxide content were basically consistent, while the deviation of the higher sodium hydroxide content was within ± 0.2g /L.The minimum measured data is cyanide copper plating solution, the mass concentration of sodium hydroxide is 1.4 g/L, the maximum data is zincate zinc plating solution, the mass concentration of sodium hydroxide is 190.6 g/L.
2. Determination of Carbonate
It also took two months to test both methods in parallel. The analysis result of sodium carbonate has a deviation of ±2g/L, which can be used as a reference for production guidance.The minimum measured data is the cyanide copper plating solution, the mass concentration of sodium carbonate is 42.0 g/L, the maximum data is the cyanide silver plating solution, the mass concentration of potassium carbonate is 91.1 g/L.
3. Precautions
1) Pay attention to the amount of reagent added. In the determination of sodium hydroxide, the pH of Calcium Chloride and Barium Chloride has an effect on the determination of sodium hydroxide. Both solutions have pH values of around 5.5, due to a combination of reagent hydrolysis and dissolved distilled water into carbon dioxide.When determining sodium hydroxide, the amount added should not be too much to avoid excessive Calcium Chloride or Barium Chloride solution consuming OH- after precipitating carbonate, which makes the determination result low.
2) Pay attention to the quality of reagents. Some Calcium Chloride reagent, preparation solution is slightly mixed in the light red, pH in more than 8, the need to filter and adjust the pH, filter out impurities such as iron oxide.
3) The mass concentration of the reagent preparation.The relative molecular weight of Calcium Chloride is less than that of Barium Chloride. The Calcium Chloride solution with the same concentration as 100g/ BaCl2 ·2H2O solution is 46g/L anhydrous Calcium Chloride, 60g/L Calcium Chloride dihydrate and 90g/L Calcium Chloride hexahydrate. Accordingly, 60g/L anhydrous Calcium Chloride or 90g/L hexahydrate Calcium Chloride are recommended.
4) Sewage treatment. Some analysis items can not be separated from Barium Chloride, after using to pay attention to the treatment of sewage, as long as the addition of dilute sulfuric acid or sulfate to generate Barium Sulfate is non-toxic, hospital fluoroscopic Barium meal contrast agent is barium sulfate, can enter the gastrointestinal tract, harmless to the human body.The barite powder used in the oil field to control the blowout is also barium sulfate, which means it is environmentally friendly.
4 . Conclusion
1) Analysis of sodium hydroxide in alkaline electroplating solution, Calcium Chloride can replace Barium Chloride, pay attention to the amount added;In the analysis of Sodium Carbonate, it is necessary to increase the steps of neutralizing Calcium hydroxide with hydrochloric acid after precipitation.
2) pay attention to the quality of Calcium Chloride, do the necessary purification and adjustment.
3) according to the technical requirements of the selection of Barium Chloride or Calcium Chloride, must use Barium Chloride, to do a good job of sewage treatment.
Post time: Jan-27-2021