PERFORMANCE OF ACRYLAMIDE ANIONIC COPOLYMERS IN CLARIFICATION OF BENTONITE AND CALCIUM CARBONATE SUSPENSIONS
Keywords:
Acrylamide, Anionic copolymers, Bentonite, Calcium carbonate, Flocculation, Polyelectrolytes, Suspension stability, Water treatmentAbstract
Background: High-molecular-weight polyelectrolytes play an essential role in the clarification of mineral suspensions and oil-water emulsions due to their ability to form interparticle bridges and generate mechanically stable flocs. Anionic copolymers of acrylamide with unsaturated acids are of particular interest for developing efficient and cost-effective flocculants.
Methods: In this study, novel acrylamide copolymers with acrylic acid (AA-AC) and maleic acid (AA-MC) were synthesized by free radical polymerization in aqueous medium. The copolymers were characterized by FTIR, thermal analysis, and powder X-ray diffraction. Bentonite and calcium carbonate were used as model mineral dispersions. Granulometric composition was determined by standard sieve analysis, and flocculation efficiency was evaluated by clarification tests.
Results: The granulometric distribution revealed that bentonite possesses a high proportion of fine fractions (<0.105 mm, 37.4%), maintaining colloidal stability, whereas CaCO3 is dominated by coarse particles (>0.297 mm, 52.3%) leading to faster sedimentation. Flocculation experiments demonstrated that AA-AC copolymers were more efficient in smectite-rich bentonite suspensions, while AA-MC showed higher performance in CaCO3 systems due to chelation with surface calcium ions. Both copolymers exhibited an optimal dosage window, beyond which restabilization occurred.
References
Faridi S., Mobinikhaledi A., Moghanian H., Ghaffari Khaligh S., Taromi F.A., Mohammadi Z., Aghaie E., Masoumi R. Synthesis of novel modified acrylamide copolymers for montmorillonite flocculants in water-based drilling fluid // BMC Chemistry. - 2023. - Vol. 17. - P. 125.
Nieto S., Piceros E., Quezada G.R., Robles P., Jeldres R.I. Structure-Performance Relationship of Anionic Polyacrylamide in Pyrite-Containing Tailings: Insights into Flocculation Efficiency // Polymers. - 2025. - Vol. 17. - P. 1055.
Castillo C., et al. Optimising the activity of acrylamide-based polymer flocculants via evaluation of molecular weight and charge density // Colloids and Surfaces A: Physicochemical and Engineering Aspects. - 2023. - Vol. 670. - P. 131542.
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