Dissolution behavior of representative elements from red mud (RM) by leaching with titanium white waste acid (TWWA)

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Red mud (RM) is a problematic industrial waste from alumina production.
• Developing sustainable methods for red mud treatment and resource recovery is crucial.

Purpose of the Study:

• To investigate the feasibility of using titanium white waste acid (TWWA) for red mud treatment and valuable element extraction.
• To optimize leaching parameters for sodium (Na), scandium (Sc), and aluminum (Al) recovery from red mud.
• To elucidate the leaching kinetics and mechanisms involved in the process.

Main Methods:

• Leaching experiments were conducted using TWWA on red mud.
• X-ray Diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) were used for material characterization.
• The unreacted shrinking core model (USCM) was applied to study leaching kinetics.

Main Results:

• Near 100% dealkalization efficiency was achieved.
• Leaching efficiencies for Sc and Al reached 82% and 75%, respectively.
• Cancrinite dissolution and anhydrite formation were observed; RM particle size decreased and dispersed.

Conclusions:

• TWWA is an effective reagent for treating red mud and recovering valuable elements.
• The leaching process is governed by diffusion mechanisms, with distinct apparent activation energies for Na, Sc, and Al.
• This approach offers a promising