A fluid-dynamics computer model of the flash-converting furnace shaft, which is based on basic principles, is presented. The model is fully three-dimensional and incorporates the transport of momentum, heat, and mass and the reaction kinetics between the gas and particles in a particle-laden turbulent gas jet. The k-#epsilon# model was used to describe gas-phase turbulence in an Eulerian framework. The particle-cloud model was used to track the particle phase in a Lagrangian framework. The coupling of gas and particle equations was performed through the source terms in the Eulerian gas-phase governing equations. Copper matte particles were represented as Cu_2S centre dot yFeS_x. Based on experimental observation, the oxidation products were assumed to be Cu_2O,CuO,Fe_3O_4, and SO_2. A reaction mechanism involving the external mass transfer of oxygen from the gas to the particle surface and diffusion of the oxygen through the successive layers of Cu_2-Fe_3O_4 and CuO-Fe_3O_4 was proposed. The predictions of the computer model were compared with the experimental data collected in a large laboratory furnace. Reasonable agreement between the model predictions and the measurements was obtained in terms of the fractional completion of the oxidation reactions and the sulfur remaining in the reacted particles. The relevance of the computational model for further analysis and optimization of an industrial flash-converting operation is discussed.
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