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Scale-up of the dual outlet device.
(2008)
  • Gijsbert Wierink
  • Juha Tiitinen
  • Kari Heiskanen
Abstract
This paper discusses a new method to increase flotation recovery. As known from literature, fine and coarse articles have different flotation rate constants, hydrodynamic behaviour and require different reagent regimes. The device discussed allows separate processing of finer and coarser slurry by extraction of a third stream, carrying finer slurry, from the flotation cell. By separate treatment of fine and coarse slurry operational conditions and so flotation recovery for both can be optimized more efficiently. Extraction and classification of the third stream is accomplished by low speed centrifugation and Taylor-Couette flow separation. This Dual Outlet Device (DOD) can be installed in a traditional flotation cell without need for equipment replacement. In order to asses different design options for the DOD a transparent laboratory scale model was built. For this scale model Computational Fluid Dynamics (CFD) simulations using RANS k-ε and LES turbulence models were performed. Essential insight in the dominant flow systems relevant to optimal operation of the DOD was obtained from the CFD simulations and flow visualization tests with the laboratory scale model. Based on these findings a number of configurations were investigated at pilot plant scale in a 5 m3 Outokumpu flotation cell. The results of the pilot plant study show that utilization of the DOD provides a method for in-cell control over particle size distribution in the slurry. Use of the DOD in a flotation cell may enhance flotation recovery and decrease flotation reagent consumption significantly, against marginal investment and operation costs.
Keywords
  • Flotation machines,
  • Fine particle processing,
  • scale-up,
  • CFD
Publication Date
September 26, 2008
Citation Information
Wierink, G.A., Tiitinen, J., and Heiskanen, K., "Scale-up of the dual outlet device". In: Proc XXIV IMPC, Beijing, China, September 24-28, 2008, pp. 4176-4182.