Effect of Molecular Weight of Poly(N-isopropyl acrylamide) Temperature-Sensitive Flocculants on Dewatering
Haihong Li, John-Paul O'Shea, George V Franks
AICHE JOURNAL | WILEY | Published : 2009
The influence of molecular weight (MW) and dose of Poly(N-isopropyl acrylamide) (PNIPAM) (temperature-sensitive flocculant) on sedimentation rate, sediment density, and supernatant clarity of silica suspensions was investigated. The addition of PNIPAM resulted in rapid sedimentation (T>critical solution temperature, CST) and low sediment moisture (T < CST). Higher MW polymers resulted in more effective flocculation and sediment consolidation. At 10 ppm, PNIPAM (3.6 million Da) produced 20 m/h settling rate and 48 vol % solids sediment density, whereas 0.23 million Da polymer produced 0.1 m/h settling rate. PNIPAM produces effective flocculation and consolidation by cycling the interparticle ..View full abstract
Awarded by Australian Mineral Science Research Institute (AMSRI)
The authors acknowledge financial support from the Australian Research Council, AMIRA International, BHP/Billiton, RioTinto, Orica, Anglo Platinum, Xstrata, and Phelps Dodge through the Australian Mineral Science Research Institute (AMSRI) (LP0667828). Thanks to Stephen Tanurdjaja for helping with studying the influence of shear on the aggregation behavior. Thanks to A/Prof. Greg Qiao for help with polymer synthesis and characterization.