Title | Laboratory study of freeze-thaw dewatering of Albian mature fine tailings (MFT) |
Publication Type | Thesis |
Year of Publication | 2012 |
Authors | Zhang, Y. |
Pagination | 208 pages |
Publisher | University of Alberta Department of Civil and Environmental Engineering |
Place Published | Edmonton, AB |
Publication Language | eng |
Keywords | geotechnical properties, tailings, tailings treatment, UofA |
Abstract | Tailing ponds in Northern Alberta has covered an area of 170 km2. Directive 074 issued in 2009 set stringent criteria for tailings reclamation. Freeze-thaw dewatering is one of the most promising approaches for dewatering MFT as one cycle of freeze-thaw can release up to 50% pore water. In this research, freezing tests were conducted with different temperature boundaries. A lower freezing rate induced higher solids content and higher undrained shear strength. In addition, finite strain consolidation tests were performed on both as-received and frozen/thawed MFT. Freeze-thaw decreased the compressibility to about half that of as-received MFT and increased the permeability to 6 times that of as-received MFT with the same void ratio. Both compressibility and permeability curves converged at higher effective stress (σ’=100 kPa). The coefficient of consolidation of frozen/thawed MFT was larger at lower effective stress and smaller at higher effective stress, comparing with that of as-received MFT. These results can be used to predict the field behaviors of Albian MFT and optimize the application of freeze-thaw dewatering. |
URL | http://hdl.handle.net/10402/era.25691 |
Locational Keywords | Alberta oil sands |
Active Link | |
Group | OSEMB |
Citation Key | 52743 |