ZETAG® 4100 DK is an anionic polyacrylamide (A-PAM), not cationic.

Below is a clear technical explanation of its type and its main applications.

1. Polymer Type of ZETAG® 4100 DK

• Polymer class: Polyacrylamide

• Ionic character: Anionic

• Charge density: Low to medium anionic

• Molecular weight: Very high

• Physical form: Dry granular powder

Because of its anionic charge and very high molecular weight, ZETAG® 4100 DK works mainly through polymer bridging, not charge neutralization. This makes it suitable for mineral-based slurries and alkaline process conditions.

2. Why ZETAG® 4100 DK Is Anionic (Not Cationic)

• Red mud, mineral tailings, and metal oxide particles often have positively charged sites or polyvalent cations on their surfaces under alkaline conditions.

• Anionic polyacrylamide chains adsorb strongly onto these surfaces.

• The long polymer chains form bridges between particles, creating large, fast-settling flocs.

Cationic polyacrylamides are mainly used for organic sludge dewatering (e.g., sewage sludge), whereas ZETAG® 4100 DK is optimized for inorganic, mineral-rich slurries.

3. Main Applications of ZETAG® 4100 DK

3.1 Alumina Refining – Red Mud Settling (Bayer Process)

The most important application of ZETAG® 4100 DK is in alumina refineries for red mud separation:

• Primary settlers

• Secondary thickeners

• Washer thickeners

• High-solids red mud thickeners

ZETAG® 4100 DK aggregates ultra-fine red mud particles, resulting in:

• Faster settling rates

• Clear overflow liquor

• Higher underflow density

• Reduced soda and alumina losses

This improves liquor recovery, washing efficiency, and residue handling.

3.2 CCD Washing Circuits (Counter-Current Decantation)

In CCD circuits, ZETAG® 4100 DK:

• Stabilizes thickener operation

• Prevents fine solids carryover into overflow

• Improves displacement washing efficiency

• Maximizes recovery of caustic soda

The result is lower wash-water consumption and improved process economics.

3.3 High-Solids Red Mud Thickeners & Residue Disposal

ZETAG® 4100 DK is widely used in high-density thickeners prior to residue disposal:

• Produces compressible, shear-resistant flocs

• Enables higher underflow solids

• Reduces slurry volume and pumping energy

• Improves stability for thickened tailings or dry stacking

This application is critical for modern, environmentally compliant residue disposal systems.

3.4 Mineral Processing & Tailings Management

Outside alumina refining, ZETAG® 4100 DK is used in:

• Copper, gold, iron ore, coal, and phosphate plants

• Tailings thickeners and clarifiers

• Process water recovery systems

Key benefits include:

• Faster settling

• Clear recycle water

• Increased thickener throughput

• Reduced tailings storage volume

3.5 Industrial Water & Process Water Clarification

ZETAG® 4100 DK is also applied in:

• Process water clarification

• Cooling water treatment

• Wash-water and stormwater clarification

• Industrial effluent polishing

It removes fine suspended solids and reduces turbidity, often used together with coagulants such as polyamine or inorganic salts.

4. Summary Table

Conclusion

✔ ZETAG® 4100 DK is an anionic polyacrylamide.
✔ It is primarily used for red mud settling, mineral tailings thickening, and process water clarification.
✔ Its high molecular weight and anionic charge make it ideal for inorganic, alkaline, high-solids systems, especially in alumina and mining operations.