Revue de Métallurgie vol:105 issue:5 pages:255-262
ATS International Steelmaking Conference location:Paris, France date:13-14 December 2007
Dissolution of ZrO2 oxide in synthetic CaO - Al2O3 - SiO2 - Na2O - B2O3 mould fluxes was investigated in situ using a Confocal Scanning Laser Microscope (CSLM). Evolution of particle radius with time is obtained exhibiting strong dependence on temperature and basicity of the mould fluxes. The rate-limiting step of the dissolution process was discussed and basicity was shown to significantly influence the rate-limiting step. In the flux with the basicity of 1, ZrO2 dissolution is controlled by mass transfer in the boundary layer and the effective diffusion coefficient is estimated to be on the order of 10-12 m(2)/s with apparent activation energy of 167.24 kJ/ mol. However, in the flux with a basicity of 0.5, the dissolution is controlled by diffusion in the flux and the effective diffusion coefficient is on the order of 10-10 m(2)/s with apparent activation energy of 200 kJ/mol.