SMAS-based flocculants perform better than common PAM for negatively charged fine coal slime in coal washing wastewater.
- Sodium Methallyl Sulfonate (SMAS) introduces stable anionic sulfonate groups with strong salt tolerance against dissolved inorganic salts in coal wastewater, while standard PAM easily curls under high mineral ion content and loses bridging capacity.
- Permanent –SO₃⁻ on SMAS copolymer generates lasting electrostatic repulsion and bridging to gather tiny negative coal particles; ordinary anionic PAM’s carboxylate gets shielded by multivalent metal cations and weakens flocculation.
- SMAS-modified copolymer has superior hydrophilicity to disperse evenly, forming dense large flocs for fast sedimentation unavailable to regular PAM.
