Effect of Lime Particle Size on Melting Behavior of Lime-containing Flux

By use of an infrared-ray vacuum furnace, effect of CaO particle size on melting behavior of lime-containing flux is studied in the present work. Two kinds of CaO particles of the average diameters of 10 μm and 75 μm are used. Four kinds of lime-containing fluxes are employed, which are CaO–SiO2, CaO–FeO, CaO–SiO2–Al2O3 as ironmaking slag and CaO–SiO2–FeO as steelmaking slag.The relationships of reaction products, heating temperature and holding time are obtained for the fluxes of CaO–SiO2 and CaO–FeO under the present experimental conditions. As for the flux melting, decreasing the lime particle size can shorten the holding time, but can not decrease the heating temperature. In the melting process of CaO–SiO2, a layer of 2CaO·SiO2 is observed on the periphery of CaO particle, which tends to inhibit the melting of CaO particles. Decreasing the CaO particle size can also effectively promote the dissolution of CaO particles into both kinds of slag of CaO–SiO2–Al2O3 and CaO–SiO2–FeO.