Variations in the molecular weight response of anionic polyacrylamides under different flocculation conditions
| Autor: | Phillip D. Fawell, Shaun Travaglini, Holger Misslitz, Allan Costine, A. S. Lubansky, James Cox |
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| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Flocculation Chromatography Applied Mathematics General Chemical Engineering Sodium Mixing (process engineering) chemistry.chemical_element 02 engineering and technology General Chemistry Polymer 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Industrial and Manufacturing Engineering 0104 chemical sciences Shear (sheet metal) chemistry Settling Chemical engineering Slurry 0210 nano-technology Intensity (heat transfer) |
| Zdroj: | Chemical Engineering Science. 176:127-138 |
| ISSN: | 0009-2509 |
| DOI: | 10.1016/j.ces.2017.10.031 |
| Popis: | The influence of applied mixing (intensity and duration), solids concentration, and liquor chemistry on the molecular weight (MW) response of seven anionic (30%) polyacrylamides was investigated in the flocculation of standard kaolin slurry at pH 8. Continuous flocculation was achieved in a Couette mixing device (CSIRO Shear Vessel) with a vertical flow-through arrangement allowing operator-independent settling rate measurements to be made under tightly controlled mixing conditions. It was found that the relative performance of the flocculants was strongly dependent on the hydrodynamic conditions prevailing during flocculation. The lower MWs gave a more dosage-effective response under mild mixing, producing denser, faster-settling aggregates than equivalent sizes produced with the higher MWs. Conversely, the larger sizes created by the higher MWs gave access to faster settling rates under intense mixing, except in the instance where polymer size and concentration led to chain entanglements. Sodium cations ( |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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