PRAESTOL  2640 is a high–molecular weight anionic polyacrylamide flocculant developed for efficient solid–liquid separation in a wide range of industrial and municipal processes. With its strong anionic charge density and long polymer chains, PRAESTOL 2640 provides excellent adsorption and bridging between fine suspended particles, forming large, stable flocs that settle rapidly. Because of its reliable performance, chemical stability, and adaptability to harsh operating conditions, PRAESTOL 2640 is widely applied in mining, alumina refining, wastewater treatment, sludge dewatering, and energy-related industries.

1. Application in Mining and Mineral Processing

One of the main application areas of PRAESTOL 2640 is mining and mineral processing, particularly in tailings thickening and clarification systems. During crushing, grinding, and flotation, large quantities of fine mineral particles are generated. These particles are difficult to settle naturally due to their small size and surface charges.

PRAESTOL 2640 adsorbs onto the surface of mineral particles and creates polymer bridges that bind multiple particles together. This results in the formation of large, dense flocs with high settling velocity. In copper, gold, iron ore, coal, phosphate, and bauxite operations, PRAESTOL 2640 improves thickener performance by increasing settling rates, raising underflow solids concentration, and producing clearer overflow water. Improved water recovery allows mining operations to recycle process water efficiently, reducing freshwater consumption and minimizing tailings storage volumes.

2. Application in Alumina Refining and Red Mud Treatment

PRAESTOL 2640 is extensively used in alumina refineries operating under the Bayer process, especially in red mud settling, thickening, and washing circuits. Red mud consists of extremely fine particles and is highly alkaline, which makes solid–liquid separation particularly challenging.

Anionic polyacrylamide PRAESTOL 2640 performs effectively under the high pH and elevated temperature conditions typical of alumina refining. When dosed into settlers and washers, it accelerates red mud settling, improves mud compaction, and enhances washing efficiency. As a result, clearer overflow liquor is achieved, improving recovery of sodium aluminate and reducing caustic soda losses. These benefits directly contribute to lower operating costs, improved process stability, and reduced environmental impact in alumina production.

3. Application in Industrial Wastewater Treatment

In industrial wastewater treatment, PRAESTOL 2640 is used to remove suspended solids, fine inorganic particles, and colloidal matter from effluents. Industries such as metallurgy, cement manufacturing, chemical processing, textiles, power generation, and building materials production depend on effective flocculation to meet discharge regulations or enable water reuse.

PRAESTOL 2640 is often applied in combination with inorganic coagulants such as ferric chloride, aluminum sulfate, or polyaluminum chloride. The coagulant neutralizes particle charges, while PRAESTOL 2640 promotes floc growth through polymer bridging. This combination improves sedimentation, dissolved air flotation (DAF), and filtration efficiency, resulting in lower turbidity, reduced sludge volume, and more stable wastewater treatment operation.

4. Application in Municipal Water Treatment

In municipal water treatment plants, PRAESTOL 2640 is used as a flocculant or flocculation aid for raw water clarification. It is particularly effective when treating surface water sources with high turbidity caused by silt, clay, or fine suspended solids.

By forming strong, shear-resistant flocs, PRAESTOL 2640 enhances sedimentation performance and reduces the load on downstream filtration units such as sand filters or membrane systems. This leads to longer filter run times, reduced backwashing frequency, and improved overall treatment efficiency and drinking water quality.

5. Application in Sludge Thickening and Dewatering

PRAESTOL 2640 is widely used as a sludge conditioning agent in both industrial and municipal sludge treatment. Sludges often contain fine particles and colloids that retain water and are difficult to dewater efficiently.

When applied prior to gravity thickening or mechanical dewatering, PRAESTOL 2640 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 requirements, and disposal costs, making sludge management more economical.

6. Conclusion

PRAESTOL® 2640 is a versatile and high-performance anionic polyacrylamide flocculant with proven applications in mining, alumina refining, industrial and municipal wastewater treatment, and sludge dewatering. By enhancing settling, thickening, and clarification efficiency, it supports improved water recovery, reduced operating costs, and better environmental compliance. Its reliability and adaptability make PRAESTOL 2640 an essential component in modern solid–liquid separation and water management systems.