liquid Anionic polyacrylamide Nalco Synfloc 9779 or Cytec HX-6300 used in red mud thickening.
Synfloc 9779 or Cytec HX-6300 are polymer which have negative charge and very high molecular weight (about 18 million). The polymer may
be type NHPA (polyacrylate neutralised with ammonia) or traditional PAM (polyacrylamide). These polymers are used in red mud thickening.
Liquid anionic polyacrylamide is indeed commonly used in the settling and separation of red mud in the alumina production process, particularly
in the Bayer process. Red mud is the solid residue left behind after extracting alumina from bauxite ore using caustic soda. Here's how liquid
anionic polyacrylamide is applied for red mud settling:
Red Mud Thickening: Red mud typically contains a significant amount of caustic liquor, which needs to be separated and recovered. Liquid anionic
polyacrylamide is added to the red mud slurry to promote flocculation and agglomeration of fine solids in the slurry. This process thickens the red
mud by allowing solids to settle more rapidly.
Clarification: The addition of anionic polyacrylamide helps clarify the caustic liquor by aiding in the separation of solid particles from the liquid phase.
This results in a clearer supernatant solution that can be recycled for further alumina extraction or other process steps.
Improved Settling Efficiency: Anionic polyacrylamide works by forming a network or polymer bridges between suspended particles, which encourages
these particles to coalesce and settle more effectively. This enhanced settling efficiency reduces the amount of caustic liquor retained in the red mud,
improving the overall efficiency of the alumina extraction process.
Dewatering: The use of anionic polyacrylamide can also aid in the dewatering of the thickened red mud cake, reducing the moisture content and
facilitating its disposal or further processing.
The specific dosage and application of liquid anionic polyacrylamide can vary depending on the characteristics of the red mud and the process
conditions at a particular alumina production facility. The goal is to achieve efficient settling and separation while minimizing the environmental
impact of red mud disposal.
It's essential to work with chemical engineers and experts who are knowledgeable about the specific requirements of your alumina production
process to ensure that the use of anionic polyacrylamide is optimized for your application while adhering to safety and environmental regulations.