Can sulfate ions in aluminum hydroxide be detected?
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It is suspected that the aluminum hydroxide raw material used in our factory contains a high amount of sulfate ions, so testing has been conducted on it. Is it necessary to test for sulfate in aluminum hydroxide finished products, and how is this analysis carried out?
Buy a bottle of barium chloride solution, take some sample, and titrate it with the barium chloride solution; if sulfate or carbonate ions are present, precipitates will form.
The approach suggested upstairs is clearly not feasible; aluminum hydroxide is an amphoteric hydroxide that forms a gel when dissolved in water. Using your method, it’s impossible to determine whether barium sulfate has been formed or not. I think it would be better to use infrared spectroscopy or mass spectrometry!
Infrared and mass spectrometry can be used for qualitative analysis; it’s not clear whether quantitative analysis is possible. Additionally, since these methods are used in factory production, applying mass spectrometry etc. doesn’t really suit the requirements of large-scale production. I hope everyone can think of more solutions to help address this issue. Thank you!
Al(OH)3 + NaOH = NaAlO2 + 2H2O; Al(OH)3 + OH- = AlO2- + 2H2O. 1: Dissolve using a strong alkaline solution. 2: For a bottle of barium chloride solution, take some sample and titrate it with barium chloride solution; if sulfate or carbonate ions are present, precipitates will form
Add a little barium chloride (lead acetate) to the solution; if a precipitate forms, then add a little dilute hydrochloric acid to the solution. If the precipitate does not dissolve, it indicates the presence of sulfate ions, as both barium sulfate and lead sulfate are insoluble in acids. You can try it this way
If hydrochloric acid is added to the solution, will it cause the sodium aluminate solution to precipitate, thereby increasing the amount of sediment? Anyway, I’ll give it a try first; please, experts, come up with some better ideas
The aluminum hydroxide we produce contains sulfate ions, which are difficult to remove