Speaker
Description
A Gibbs energy minimization algorithm [1] has been developed and is used for calculating phase equilibria in the quinary slag system CaO-SiO2-FeO-MgO-MnO. Assuming local equilibrium at the solid-liquid interface, the kinetics of lime dissolution in this system is simulated by means of a finite-difference diffusion model. Different initial lime particle geometries such as plates, cylinders and spheres can be considered. Experimental observations [2] indicate that the first, comparably fast dissolution stage of the lime particle is competed by the formation of a boundary phase retarding the dissolution kinetics of the particle. The intermediate dissolution process characterized by the formation and dissolution of the boundary phase is considered by a reduced effective diffusion coefficient. Comparison of the simulated results with dissolution kinetics deduced from experimental data suggests that diffusion-convection processes are the rate-controlling dissipative processes for the dissolution of the particle.
[1] M.H.A. Piro, S. Simunovic, T.M. Besmann, B.J. Lewis, W.T. Thompson: “The thermochemistry library Thermochimica”, Comp. Mater. Sci. 67 (2013) 266-272
[2] X. Guo, Z.H.I. Sun, J. Van Dyck, M. Guo, B. Blanpain: “In Situ Observation on Lime Dissolution in Molten Metallurgical Slags − Kinetic Aspects”, Ind. Eng. Chem. Res. 53 (2014) 6325−6333
Key Words: Gibbs energy minimization, metallurgical processes, thermodynamics, kinetics of metallurgical reactions
| Speaker Country | Austria |
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