Abstract: For converter gasification dephosphorization slag system, the kinetics of static lime dissolution in slag was studied. The research results show that in the temperature range of 1 200～1 500 ℃, as the temperature increases, the melting rate of lime increases, the activation energy of lime melting is E_a=203.1 kJ/mol, the linear equation fitting the relationship between the rate constant and the temperature is ln v_r=-24.43/T-14.62. The limiting link of lime melting is diffusion control. Analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD) the molten slag layer-the boundary layer-the lime layer, the research results show that the migration rate of the slag component Fe²⁺ is faster than the migration rate of SiO₄^4-, from the lime surface to the inside, CaO-SiO₂ composite phase is mainly formed on the lime surface, and more Fe elements will be present inside, forming the main CaO-FeO composite phase.

Key words: gasification dephosphorization slag, lime, melting, diffusion, activation energy