From Primary Settling with SettleMax to Secondary Dewatering with Specialized Polymers

Oil sands extraction generates vast volumes of tailings—a mixture of water, sand, clay, and residual bitumen—that present significant environmental and operational challenges. Fluid fine tailings (FFT) settle slowly, contributing to large tailings ponds. As of mid-2025, Alberta’s oil sands operations manage approximately 1.2 billion cubic metres of fluid tailings, with ongoing efforts to reduce legacy volumes through treatment and reclamation under the Tailings Management Framework (TMF).

Effective management requires a two-stage approach: primary settling to accelerate initial clarification and secondary dewatering to achieve dry, trafficable material for reclamation.

Primary Settling with SettleMax: Accelerating Floc Formation and Clarification

SettleMax is a high-performance settling aid specifically engineered to address the challenges of slow-settling fines in oil sands tailings. It promotes rapid aggregation of fine particles into larger, denser flocs, enhancing settling rates, reducing turbidity, and improving sludge compaction.

SettleMax excels in multiple applications:

• Primary Clarifiers: Rapidly forms dense flocs for clearer overflow water and thicker underflow.
• Tailings Ponds: Accelerates densification of mature fine tailings (MFT), releasing trapped water and reducing pond volumes.
• Process Clarifiers: Lowers turbidity, enabling higher water recycling rates (supporting industry averages of around 79%).

Its targeted polymer chemistry overcomes repulsion from bitumen residues and salinity, delivering faster throughput, denser deposits, and better compliance with Alberta Energy Regulator (AER) directives.

Secondary Dewatering: The Critical Role of Specialized Polymers

After primary settling, mature fine tailings often retain low solids content (30-40%), trapping water in a gel-like structure. Secondary dewatering is essential to transform these into dry-stackable material.

High-molecular-weight polymers—tailored as anionic, cationic, or dual systems—create shear-resistant flocs that release trapped water during mechanical processes:

• Floc Formation and Water Release: Polymers bridge particles into large aggregates.
• Synergy with Mechanical Methods: Combined with centrifugation, filtration, or thin-lift drying, achieves solids contents over 60%.
• Advanced Options: Dual-polymer dosing or modified polymers enhance water release and shear strength.

Benefits include reduced tailings volume, improved water recovery, faster reclamation, and lower long-term liability—aligning with 2025 regulatory advancements for treated water management.

At East to West Consulting, we integrate SettleMax for primary treatment and optimize polymer strategies for secondary dewatering, drawing on European expertise adapted to Canadian oil sands. Contact us for tailored solutions to enhance your tailings performance.