T. Ahokainen

Modelling gas injection of a Peirce–Smith-converter

Abstract A commercial CFD-code PHOENICS was used to solve isothermal flow field of gas and liquid in a Peirce–Smith-converter. An Euler–Euler based algorithm was chosen for modelling fluid dynamics and evaluating controlling forces of a submerged gas injection. Predictions were made with a k – e turbulence model in the body fitted coordinate system. The model has been verified with a 1/4 scale water model, and a parametric study with the mathematical model of submerged gas injection was made for the PS-process and the ladle injection processes. Limits of the modelling technique used were recognised, but calculated results indicate that the present model predicts the general flow field with reasonable accuracy. Predicted bubble distribution, pattern of the flow field and magnitude of flow velocities were used to evaluate scaling factors of physical models and general flow conditions of an industrial PS-converter.

Experimental and Computational-Fluid-Dynamics Simulation of the Outokumpu Flash Smelting Process

The Outokumpu flash smelting process has been developed for the production of copper, nickel and lead from their sulphidic concentrates by Outokumpu Oy. To date, there are 38 flash smelting licences sold for copper, nickel and sulphur production world-wide. At present the use of complex concentrates in large amounts in the flash smelting process is not possible, due to the accumulation of impurities in the present plant practice where flue dust is circulated. If it were technically possible to smelt complex concentrates in the flash smelting furnace, it would make vast resources of relatively low-cost raw materials available to flash smelters. However, different practices for treating complex copper and nickel concentrates in the flash smelting furnace can be studied with combined laboratory studies and computer simulations. Computer simulation of flash smelting requires a substantial knowledge of the behavior of particles during their flight in the particle-gas suspension. The reactions taking place in t...