Skip to main content


Hitachi Infrastructure Systems (Asia) Pte. Ltd.

This new fluorine removal device meets the regulations.


This device takes the residual fluorine in the sedimented treated waste water that contains hydrofluoric acid and changes the fluorine to apatite, and precipitates it on the surface of the crystallized material. The device has an expanded-layer reactor structure, so it is simpler, has easier maintenance management, and lower cost than existing 2-stage coagulation sedimentation devices.


  1. Simple device configuration & low initial cost
    Complicated, expensive machinery not used.
  2. The increased crystallized material is recycled
    The extra crystallized material can be recovered as a valuable chemical raw material, so it doesn't need to be disposed of as industrial waste. Also, water drains out easily, so there is no need for a dehydration process.
  3. Reduces maintenance work
    The system can be operated only with control-system pH control, which reduces maintenance management work.
  4. Conserves space
    Large devices like sedimentation tanks aren't necessary, which conserves space.

(in-house comparison)

System Overview

Image: Structural diagram of device

Image: Precipitating fluorine apatite on the surface of the crystallized material

Waste water passes through the crystallized material-filled expanded layer reactor by upward flow. Phosphoric acid is added to the waste water, and fluorine apatite is formed on the surface of the seed crystals.

Image: Relationship graph: Fluorine concentration in inflow waste water and concentration in treated water

Photograph: Device appearance
Device appearance

System Flow

Existing method

Image: Existing method

New crystallization method

Image: New crystallization method


  • Fluorine removal device