Flash reaction of sulfide mineral particles in a turbulent gas jet

A comprehensive mathematical model that combines turbulent transport phenomena of particle-laden gas jets, chemical reactions, and thermal radiation has been developed to describe the various aspects of chalocopyrite concentrate combustion that includes minor element behaviour inside an axisymmetric reaction shaft of the flash-furnace. This model has elucidated the relative importance of elimination of the four most undesirable minor elements: As, Sb, Bi, and Pb to the gas phase.; The experiments were carried out in a laboratory flash furnace. Gas temperature, sulfur content in the particles, SO{dollar}sb2{dollar} concentration in the gas phase, particle dispersion, and the average elimination of minor elements to the gas-phase during flash-smelting at different locations were measured for various target matte grades. Reasonable agreement was obtained between the measured and predicted values.; Numerical computations have been performed to predict the various aspects of rate processes occurring in a commercial-scale flash-smelting furnace for different inlet feeding modes. Model predictions indicate that the overall performance of the flash-smelting furnace is greatly affected by the inlet geometry and the gas-phase turbulent field is significantly affected by the presence of particles. It also shows that the reaction of sulfide particles is almost completed in the upper zone of the furnace within about 1 m from the burner, and the axial wall feeding mode of the secondary jet shows better performance than any other feeding modes considered in this study.; Satisfactory agreement between the predicted and measured results was obtained for antimony and lead. No experiments were obtained for arsenic and bismuth due to experimental difficulties and the toxicity of these elements. From the computational results, the behavior of each minor element was predicted for various target matte grades.; The model predictions show that in the laboratory flash furnace, the elimination of As and Bi to gas-phase increases sharply at about 0.3 m from the burner; however, that of Sb increases gradually along the flash-furnace shaft, and that of lead occurs suddenly at about 0.6 m from the burner. The elimination increases as the target matte grade increases for Bi and Pb; however, it is relatively independent of the target matte grade between 50 and 60 pct Cu for As and Sb. At higher target matte grades above 60 pct Cu, the elimination of As and Sb decreases as matte grade increases. The model predictions also show that in a commercial flash furnace, the elimination of all minor elements levels off at about 3 m from the burner.