Numerical simulation of the outokumpu flash smelting furnace reaction shaft

A kinetics-based mathematical model of the Peirce-Smith converter has been developed. The model considers mass transfer, heat transfer, and reactions between each of the phases present in the converter. Model validation is carried out using industrial data obtained from both copper and nickel converters. The model is generally able to predict the temperature and compositional variations of the converters to within the errors of the industrial data. However, the interactions between the white metal and slag during the copper blow are not understood sufficiently to model well.

A kinetic model of the peirce-smith converter: Part I. Model formulation and validation

Multiphase equilibrium modeling of oxygen bottom-blown copper smelting process

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-ɛ 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 Cu2S · yFeSx. Based on experimental observation, the oxidation products were assumed to be Cu2O, CuO, Fe3O4, and SO2. 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 Cu2O-Fe3O4 and CuO-Fe3O4 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.

Experimental investigation and three-dimensional computational fluid-dynamics modeling of the flash-converting furnace shaft: Part II. Formulation of three-dimensional computational fluid-dynamics model incorporating the particle-cloud description

The ignition and combustion of chalcopyrite particles under suspension-smelting conditions, in which the particle-particle interaction is neglected, has been analyzed by considering the in-trinsic kinetics of oxidation and heat and mass transfer between the particle and its surroundings. Reasonable agreement has been obtained between the calculated results and experimental results from a laminar-flow furnace reported in the literature. This computational procedure has also been applied to flash-smelting conditions. Under suspension-smelting conditions (Sh = Nu = 2), chalcopyrite particles ignite at approximately 960 K. The effects of various parameters, such as oxygen concentration, particle size, and gas temperature, have also been evaluated. Comparison between calculated results in this work and experimental observations indicates that SO is the important gaseous product that forms at the particle surface.

The ignition and combustion of chalcopyrite concentrate particles under suspension-smelting conditions

The mathematical model described in Part I[14] was extended to include the minor element behavior inside a flash-furnace shaft during flash smelting of copper concentrate. The volatilization of As, Sb, Bi, and Pb was computed, and experiments were carried out for Sb and Pb in a laboratory flash furnace. Satisfactory agreement between the predicted and measured results was obtained for antimony and lead. From the computational results, the behavior of each minor element was predicted for various target matte grades. The model predictions show that the elimination of As and Bi to the gas phase increases sharply at about 0.3 m from the burner; however, that of the Sb increases gradually along the flash-furnace shaft, and that of lead occurs suddenly at about 0.6 m from the burner. The predicted results also show that the elimination increases for Bi and Pb as the target matte grade increases; however, it is relatively independent of the target matte grade between 50 and 60 pet Cu for As and Sb. At higher target matte grades above 60 pet Cu, the elimination of As and Sb decreases as matte grade increases.

K. W. Seo

Papers

Mathematical modeling of sulfide flash smelting process: Part III. Volatilization of minor elements