Abstract Corrosion of refractories is possible to characterize as wear by affecting of environment as solids, melts and gases. This affecting may be mechanical, chemical, physicochemical and physical. Corrosion of refractories we understand as dissolution of solid in the liquids. Dissolution is physico-chemical process with changing of chemical composition of solids and liquids. The liquid layer which contacts surface of solid phase is enriched by dissolved substance. It results into changes in the structure of the melt and also changes of physical properties evocate vertical and horizontal hydro-dynamical flow of the melt in effective diffusion layer and this process consequently creates corrosion profile of solid phase. Basic properties of slag melts is very important for chemical corrosion of refractories, but the same importance on wear of refractories have physico-chemical properties of slag melts (mainly surface tension, density and viscosity) which expressed inside structure of melts. According to results of density and surface tension measurements is visible, that after melting of slag system FeO – SiO2 the molecule structure is dissociated on simple cations (Fe2+ and FeO+), anion complexes (SiO44+,FeO2-) and clusters (2FeO.SiO2). Addition of CaO, Al2O3 and MgO into basic slag system creates process of corrosion dissolution of basic refractories in fayalite slag. Change of the chemical composition of melt brings about change of its structure and change of physical properties of melt (density and surface tension). As a result is free flow on the boundary and creation the corrosion profile of solid substance submerged in the melt.