Application of ALCLAR HP-21 Anionic Polyacrylamide

ALCLAR  HP-21 is a high–performance anionic polyacrylamide flocculant specifically designed for solid–liquid separation processes in mining, mineral processing, alumina refining, industrial wastewater treatment, and sludge dewatering applications. With its high molecular weight, controlled anionic charge density, and long polymer chains, ALCLAR HP-21 offers excellent adsorption and bridging capabilities. This enables fine suspended particles to aggregate into large, dense flocs, improving settling rates, clarification efficiency, and overall water recovery. Its stability under challenging chemical and physical conditions makes it highly suitable for industrial processes requiring reliable and consistent performance.

1. Application in Mining and Mineral Processing

One of the primary applications of ALCLAR HP-21 is in the mining and mineral processing industry, especially in tailings thickening, clarification, and water recovery circuits. During crushing, grinding, and flotation processes, significant amounts of fine mineral particles are generated. These particles tend to remain suspended for long periods due to their small size and surface charges, which hinders natural settling.

ALCLAR HP-21 adsorbs onto the surfaces of mineral particles and forms polymer bridges between them, leading to the formation of large, compact flocs. These flocs settle rapidly in thickeners, improving settling rates and increasing underflow solids concentration. In operations involving copper, gold, iron ore, coal, phosphate, and bauxite, ALCLAR HP-21 enhances thickener throughput, produces clearer overflow water, and facilitates efficient recycling of process water. By reducing freshwater consumption and minimizing tailings storage requirements, it contributes to operational efficiency and environmental sustainability.

2. Application in Alumina Refining and Red Mud Treatment

ALCLAR HP-21 is widely used in alumina refineries operating under the Bayer process, particularly in red mud thickening, settling, and washing circuits. Red mud is composed of extremely fine and highly alkaline particles, which are challenging to separate due to strong electrostatic repulsion and high slurry viscosity.

The chemical stability and high performance of ALCLAR HP-21 allow it to operate effectively under the high pH and elevated temperature conditions typical of alumina refining. When dosed into settlers and washers, ALCLAR HP-21 accelerates red mud settling, improves mud compaction, and enhances washing efficiency. The resulting clearer overflow liquor improves recovery of sodium aluminate and reduces losses of caustic soda. Additionally, improved washing lowers residual alkalinity in disposed mud, supporting safer residue management and environmental compliance.

3. Application in Industrial Wastewater Treatment

In industrial wastewater treatment, ALCLAR HP-21 is used to remove suspended solids, colloidal particles, and fine inorganic matter from effluents. Industries such as metallurgy, cement manufacturing, chemical processing, textiles, and power generation depend on efficient flocculation to meet discharge standards or enable water reuse.

ALCLAR HP-21 is often applied in conjunction with inorganic coagulants such as aluminum sulfate, ferric chloride, or polyaluminum chloride. The coagulant neutralizes particle surface charges, while ALCLAR HP-21 promotes floc growth and strengthens floc structure through polymer bridging. This combination enhances sedimentation, dissolved air flotation (DAF), and filtration performance, resulting in lower turbidity, reduced sludge volume, and more stable treatment operation. Its use contributes to lower chemical consumption and improved operational efficiency.

4. Application in Municipal Water Treatment

In municipal water treatment, ALCLAR HP-21 serves as a flocculation aid for raw water clarification. It is particularly effective when treating surface water with high turbidity caused by clay, silt, or fine suspended solids.

By forming large, shear-resistant flocs, ALCLAR HP-21 improves sedimentation efficiency, reducing the load on downstream filtration units such as sand filters or membranes. This leads to longer filter run times, reduced backwashing frequency, and lower operational costs while maintaining high-quality clarified water.

5. Application in Sludge Thickening and Dewatering

ALCLAR HP-21 is also widely applied as a sludge conditioning agent in both industrial and municipal sludge treatment. Sludges often contain fine particles and colloids that retain water, making mechanical dewatering challenging.

When applied prior to gravity thickening or mechanical dewatering, ALCLAR HP-21 improves floc structure and promotes rapid release of free water. In belt filter presses, centrifuges, and filter presses, it increases cake solids content and improves filtrate clarity. Higher cake dryness reduces sludge volume, transportation, and disposal costs, resulting in more efficient and economical sludge management.

6. Application in Energy and Power Industries

In the energy sector, particularly in coal-fired power plants, ALCLAR HP-21 is used for fly ash and bottom ash pond clarification. Ash particles are typically fine and slow to settle, leading to large settling ponds and water losses. ALCLAR HP-21 accelerates ash particle aggregation and settling, producing clearer supernatant water that can be reused for cooling or other plant processes. This improves water conservation and helps power plants comply with environmental regulations.

7. Performance Advantages

ALCLAR HP-21 provides several operational advantages, including high flocculation efficiency at low dosage, rapid floc formation, and strong floc strength that resists shear. It performs effectively over a wide pH range and is compatible with most commonly used inorganic coagulants. Its reliable performance, ease of preparation, and consistent dosing make it suitable for continuous, large-scale industrial operations.

8. Conclusion

ALCLAR® HP-21 is a versatile and high-performance anionic polyacrylamide flocculant with proven applications in mining, alumina refining, industrial and municipal wastewater treatment, sludge dewatering, and energy sectors. By enhancing settling, thickening, and clarification efficiency, it supports water recovery, reduces operational costs, and improves environmental compliance. Its robustness, adaptability, and consistent performance make ALCLAR HP-21 an essential component in modern solid–liquid separation and water management systems.