Project 1.1: Measure and Predict De-watering Performance
Iman Entezari, PhD: Applications of remote hyperspectral sensing in the characterization of Alberta's oil sands tailings
Water removal from saturated tailings is the first step in densifying and consolidating tailings. The separation of water from mature fine tailings (MFT) is thus an operational and environmental challenge of tailings management. Remote estimation of moisture content, evaporation rate, and total suction would help operators to assess the drying process, determine when the deposit has stopped drying, and decide when the next lift should be deposited. Therefore, our work provides low-risk, cost-effective quick surveys to the tailings operators to manage their large volume of tailings and thus accelerates the process of converting tailings to reclaimable landscapes.
Janeen Ogloza, MSc: Measuring Actual Evaporation Rates from a Tailings Pond
By having accurate and actual evaporation rates, oil sands operators would know when the tailings surface has reached its driest state and new tailings can be placed on the surface. As different tailings volumes (lift thicknesses) dry at different rates, the optimum point where the most tailings is placed to dry for the least amount of time could be determined. This would ensure that the tailings pond is consolidated to its maximum potential, which would aid in the reclamation of these massive tailings ponds.
Nicolas Olmedo, PhD: Tailings characterization using an unmanned ground robot
The development of autonomous systems for environmental studies is generally applicable to tailings operators and will support the efforts for reclamation of tailings impoundments. These systems can be used to obtain in situ tailings properties from treated fluid fine tailings deposits that not trafficable. The new technologies will enable characterization of deposits that are not available using conventional geotechnical tooling. This new information will aid in the understanding of the how tailings change over time, which is very important to the oil sands operators as well as the decision-making on process control and post-deposition work; and are of direct economic benefit to the oil sands industry and Canada’s economy.
Project 1.2: Determination of properties for high volume change materials
Feixia Zhang, PhD: Unsaturated Soil Property Functions for High Volume Change Materials
The coefficient of permeability function and the water storage function are two important hydraulic properties required in the numerical modeling of geotechnical problems such as transient seepage or contaminant transport that occurs during mine waste or tailings disposal. The inaccurate estimation of the hydraulic properties will cause erroneous numerical modeling results, which will then cause engineers to make inappropriate decisions concerning a project. Existing estimation techniques, such as the van Genuchten-Burdine (1980) equation, the van Genuchten-Mualem (1980) equation and the Fredlund, Xing and Huang (1994) permeability function, produce reasonable results when estimating the coefficient of permeability function and the water storage function for unsaturated soils with low compressibility such as sands or silts, but the analysis protocols require changes when predicting the coefficient of permeability and the water storage for materials that undergo volume change as soil suction changes (e.g. oil sands tailings slurry). The revised theory could be applied in the numerical modelling to facilitate a proper design of tailings disposal, reducing potential engineering costs that could have been caused by decisions based on misinformation.
Project 1.3: Assessment of Shear Strength
Bereket Fisseha, PhD: Undrained shear strength of amended oil sand tailings
The research focused on investigating fundamental soil mechanics such as stress–strain relationships and the engineering properties of FFT under saturated/unsaturated conditions. These fundamental principles will be used to predict the behaviours of FFT as accurately as possible by incorporating them into available numerical modeling softwares. Subsequently the software will be used as a tool for analysis during engineering designing at various stages such as bearing capacity earth fill structures that will be used as containment. The research program will provide a laboratory data set and analysis that leads towards narrowing the existing knowledge gap and contribute towards resolving challenges facing mine operators.
Project 1.4: Modelling of pore fluid in the computation of actual evaporation
Prempeh Owusu, MEng: Laboratory study of the effects of repeated freeze-thaw cycles on the suction behavior of centrifuged tailings
The research work focused on establishing and enhancing understanding of the influence of the effects of freeze-thaw cycles on the suction behaviour of centrifuged tailings. Knowledge of the development of osmotic suction and electrical conductivity through freeze-thaw cycles is required to evaluate potential capping and reclamation schemes in the design and construction of cover systems on centrifuged tailings.