How is fluorine separated from other materials found with it?

The following processes are used for fluorine removal:

1. filtration through activated alumina - this is the most widely used process

2. coagulation-flocculation - or aluminum sulphate treatment - can only be used on raw water that requires sedimentation and that has low fluoride content.

3. lime used to soften water - This method can be used but with a pH >10 and provided that the water has a sufficient magnesium level (high) because it is the magnesium oxide that will adsorb the fluorine. Approximately 50 mg · L-1 of magnesium is required to remove 1 mg · L-1 of fluorine.

4. using tricalcium phosphate

5. other processes

· reverse osmosis

· Electrodialysis