Computational fluid dynamics modeling of deposition of oil sand slurry into mature fine tailings

The objective of this research program is to study the feasibility of using computational fluid dynamics (CFD) approach to the modeling of dense slurry flow with a special emphasis on oil sand slurry inflow into oil sands mature fine tailings (MFT).;Sedimentation process for bidisperse and polydisperse suspension from literature are simulated using MFIX and FLUENT. Simulation results indicate that the Euler-Euler Model in those two CFD packages is capable of modeling the sedimentation process of the bidisperse and polydisperse suspension. Then the settling process of the segregating and non-segregating oil sand tailing slurry is selected to test the capability of MFIX, FLUENT-6 and CFX-10. The results show that the transient process of the sedimentation, therefore the segregation, of the tailing slurry can not be captured by those models if the viscosity of the water phase is not changed to reflect the interaction between clay particles and the water phase.;The flume test conducted by Scott et al. (1993) is simulated using the Free Surface Model and the Particle Model in CFX-10. It is found that the traveling speed of the slurry is significantly faster than was measured in the laboratory tests. The solids and fines content profiles in the simulation do not match those in the laboratory deposit.;The flow of sand slurry into the simplified MFT ponds is simulated. Segregation always occurs for non-segregation mixture using the Particle Model if a viscosity of 0.001 Pa.s is assigned to water phase. Considering MFT to be composed of sand particles and clay-water suspension results in more realistic sand particle distribution in the tailing pond using both Mixture Model and two phase Particle Model.;An experimental program is established to measure the viscosity and the yield stress of the slurry with various solids and fines contents. The viscosity and yield stress of the slurry are curve fitted using Power Law model and Herschel-Bulkley model. Then the flow curve for pure MFT is applied in the CFD simulation of the viscosity and yield stress measurements using the single phase model in CFX-10. The simulated torques reasonably agree with those from experiments.