Revisiting the large strain consolidation test for oil sands

The large strain consolidation test is a one-dimensional multi-step loading compression test used to obtain one-dimensional volume change properties of high water content material. These properties include compressibility (stress-strain behaviour) and hydraulic conductivity (ability to transmit water). The test is used worldwide for slurry and tailings work including for Alberta oil sands tailings since the 1970’s. This paper revisits this test method for use in the oil sands through the authors’ laboratory practice and a literature review. Key practical considerations and learnings are summarized to date.Applied Science, Faculty ofMining Engineering, Keevil Institute ofUnreviewedOthe

Oil sands thickened tailings : remedies from an international perspective

The deposition of conventional thickened tailings across the international mining industry has encountered many operational challenges over the years. These include variation in feed, solids content, beach establishment, stability and capacity constraints, drainage, consolidation, supernatant and fines. High quality design and operation of thickeners can prevent many of the problems encountered in tailings deposition. However, despite their best efforts, tailings managers still encounter significant challenges during deposition. This paper outlines the elements of a successful thickened tailings deposition plan and describes some of the interventions available to the tailings designer or operator, which have been successfully implemented as remedies. These include control of slurry relative density, elimination of excess water, development of a conservative deposition cycle which takes account of weather, discharge control, drainage and decanting techniques, and planning for off-specification events. It also presents potential issues with thickener implementation within the Oil Sands industry due to the nature of feed and material variability, difficulties in depositing material in the short term and long term and drying material efficiently.Applied Science, Faculty ofMining Engineering, Keevil Institute ofUnreviewedOthe