Application of ALCOTAC FE-14 SSK

ALCOTAC FE-14 SSK is a high-performance anionic polyacrylamide flocculant specifically engineered for solid–liquid separation under harsh alkaline and high-temperature conditions. It belongs to the ALCOTACSSK series, which is widely recognized in the alumina (Bayer process) industry, particularly for red mud clarification and washing circuits. Due to its optimized molecular weight distribution and charge density, ALCOTAC FE-14 SSK delivers fast settling, strong floc formation, and excellent clarity in difficult slurries containing fine, colloidal solids.

1. Application in the Bayer Process (Alumina Production)

The primary application of ALCOTAC FE-14 SSK is in the Bayer process, where bauxite is digested in hot caustic soda to dissolve alumina, leaving behind insoluble residues known as red mud. Efficient separation of red mud from pregnant liquor is critical for plant productivity, caustic recovery, and product quality.

ALCOTAC FE-14 SSK is mainly applied in:

• Primary settlers

• Secondary settlers

• Washer circuits (washers 1–3)

• High-rate and high-density thickeners

In these units, the flocculant promotes rapid agglomeration of fine red mud particles into large, dense flocs. This significantly increases settling velocity, allowing clearer overflow liquor and higher underflow solids concentration. Improved separation directly enhances alumina yield and reduces soda losses.

2. Red Mud Settling and Clarification

Red mud contains extremely fine particles, often smaller than 1 micron, with high surface charge and poor natural settling characteristics. ALCOTAC FE-14 SSK overcomes these challenges by:

• Neutralizing surface charges on red mud particles

• Bridging fine particles through long polymer chains

• Forming strong, shear-resistant flocs

As a result, the overflow liquor becomes low in suspended solids, which is essential for downstream evaporation and precipitation steps. Cleaner liquor reduces scaling, fouling, and maintenance requirements across the refinery.

3. Washer Circuit Efficiency and Caustic Recovery

In washer circuits, the objective is to wash soluble sodium aluminate and caustic soda from the red mud. ALCOTAC FE-14 SSK enhances washing efficiency by producing compact and permeable mud beds. This allows wash liquor to pass more uniformly through the solids, improving displacement washing.

Key benefits include:

• Higher caustic recovery

• Reduced soda losses in mud disposal

• Lower fresh caustic consumption

• Improved environmental performance

The ability of ALCOTAC FE-14 SSK to maintain floc integrity under high shear conditions is particularly valuable in multi-stage washer systems.

4. High-Temperature and High-Alkalinity Performance

One of the defining features of ALCOTAC FE-14 SSK is its excellent stability in extreme operating conditions. Bayer process slurries often operate at:

• pH > 12

• Temperatures above 90–105 °C

• High ionic strength and dissolved solids

ALCOTAC FE-14 SSK is formulated to retain its flocculation efficiency under these conditions, where conventional flocculants may degrade or lose effectiveness. This stability ensures consistent performance and predictable process control.

5. Improvement of Thickener Throughput

By accelerating settling and increasing underflow density, ALCOTAC FE-14 SSK enables higher thickener throughput without compromising overflow clarity. Plants can either:

• Increase production capacity using existing equipment, or

• Operate at lower flocculant dosages while maintaining performance

This flexibility makes the product attractive for both new refineries and capacity-constrained existing operations.

6. Reduction of Operating and Maintenance Costs

The application of ALCOTAC FE-14 SSK contributes to overall cost reduction by:

• Lowering flocculant consumption due to high efficiency

• Minimizing scaling and solids carryover

• Reducing equipment wear caused by abrasive fines

• Improving stability of downstream processes

Clearer liquor and more stable mud settling lead to fewer process upsets and reduced downtime.

7. Environmental and Tailings Management Benefits

In residue disposal and tailings thickening, ALCOTAC FE-14 SSK supports the formation of high-solids underflow, which reduces the volume of tailings slurry sent to disposal areas. This results in:

• Lower water content in red mud

• Reduced footprint of residue storage areas

• Improved water recycling within the refinery

These benefits align with modern sustainability and environmental compliance requirements in the alumina industry.

8. Dosage and Application Method

ALCOTAC FE-14 SSK is typically supplied as a dry powder flocculant and is prepared as a dilute aqueous solution before use. Proper make-down, aging, and dosing are essential to achieve optimal performance. Dosage depends on bauxite quality, mud characteristics, and operating conditions, but it is generally optimized through plant trials.

Conclusion

ALCOTAC FE-14 SSK is a specialized anionic flocculant designed for high-efficiency solid–liquid separation in alumina refineries. Its proven performance in red mud settling, washing, and clarification makes it a critical process aid in the Bayer process. By improving settling rates, overflow clarity, caustic recovery, and thickener capacity, ALCOTAC FE-14 SSK delivers both technical and economic benefits, supporting stable operation, higher productivity, and sustainable residue management in modern alumina production.