Slag coating on the lining surface exercised by means of nitrogen jets that splash specially treated slag with magnesium additives,has become an efficient technology to extend the lifetime of the converters refractory lining.Meanwhile,converter steelmaking practice demonstrates that the chemical composition of the final slag can fluctuate within a reasonably wide range of Fe0,SiO2,CaO,etc.concentration values.This complicates application of universal magnesium-based flux additions and set particular constrains for their efficiency.Slag oversaturation with MgO,is of special importance upon slag treatment for splashing,since Fe oxides are bound into high-melting ferritic phases ( magnesioferrite,magnesiowustite ) displacing low-melting calcium ferrites.While the input of low-soluble particles ( 3 - 5 mm " grains" ) into slag,ensures formation of a " binding backbone" within the skull layer,thus improving its mechanical strength properties and,consequently,its lifetime.Obtained results were employed for the improvement of skull coating process on the converter lining at several metals works of Ukraine.