2013 Tailings and Mine Waste Conference

Monitoring of Agglomerating Mature Fine Tailings in Pipe Reactor Flow

Date of Conference: 
November 15, 2013
Alex van der Spek, John Viega
Abstract / Introduction: 

The rheology of fluids is described by a constitutive equation which relates (wall) shear stress to (wall) shear rate. Polymer induced agglomerating of Mature Fine Tailings (MFT) will result in a varying relation between shear stress and shear rate as the reaction progresses. A velocity profiling method to monitor shear stress and shear rate in real time was developed and implemented on a field scale pipe reactor. Results indicate very little difference in the shape of the velocity profile between the turbulent flow of agglomerating MFT and the laminar flow of MFT in its native Bingham plastic state. With the change in the rheology a different mechanism of energy dissipation will evolve. In laminar flow the pressure gradient required to drive the flow is linearly related to the rate of flow. In fully developed turbulent flow the pressure gradient is quadratically related to the rate of flow. A method is described to monitor the rate of energy dissipation per unit volume from array velocity measurements. The spectrum of energy distribution over a variety of length scales is measured and compared to the Kolmogorov 5/3 law. Deviations from the latter indicate non turbulent or partially turbulent flow. Partial implementation on a field scale was accomplished using the same instrumentation as used in the velocity profiling method. Results from a field experiment show that periods

Reference number: 
Asset type: 
Technical Paper