How to remove Al ions from primary brine?
Thread Content
This post was last edited by sunjl1981 on 2013-1-6 21:47. How to remove aluminum from brine? (Is the KAI membrane process effective in controlling the pH of the primary brine?) # hcbbs
What pH level needs to be maintained? It won’t work if it’s too high or too low; it seems a bit difficult. But maybe adding some ferric chloride could help to see if it has any effect
This post was last edited by yzhms on 2009-10-23 at 16:33. I just checked on Baidu and found that the pH range for the precipitation of aluminum hydroxide is 6–10. You could try keeping the pH of the saltwater between 9 and 10, but it seems that iron trichloride still needs to be added to achieve some effect
On the one hand, it is necessary to control the excessive alkalinity of the saltwater so that it can be treated to some extent; more importantly, it is essential to identify the source and take measures to control it. Salt, water, brine, refined products?
This post was last edited by yzhms on 2009-10-23 at 16:34. Aluminum and magnesium are incompatible with high levels of alkali; it is necessary to control the pH value during processing, to avoid making it too high, as well as to pay attention to the quality of the raw salt
During a brine stage, the alkalinity level is controlled; aluminum is an amphoteric substance and thus difficult to control, but the flocculent precipitate of aluminum hydroxide, acting together with iron hydroxide, can help settle a portion of it. During the secondary brine stage, the amount of brine processed by the resin tower is increased, along with the reflux rate; this allows the brine with high aluminum content to pass through the resin tower repeatedly. Although the adsorption effect is not ideal, it can still help reduce the aluminum content to some extent. When selecting raw salt or brine, strict control is exercised over aluminum levels, and several types of salts are used together.
We have been adding ferric trichloride, and the AL level is well under control.
Will adding ferric trichloride introduce iron ions? I think it’s better to use sodium hydroxide to adjust the pH value; after precipitating and filtering out the AL ions, then add hydrochloric acid to bring the pH value to 7.
Can it be removed using ion exchange resin?
Resin primarily removes divalent metal ions; it has been observed that the aluminum content in the secondary brine is comparable to that in the primary brine.
Where should I add ferric chloride? What process do you use? We use the floating tank with KAI membrane process. Thank you!