To study mechanism of the slag coating on lining ofLD converters, uncoated and coated high carbon MgO bricks havebeen recovered and made into polished and thin sections foroptical and electron optics investigations. Slag coating practice isfirst to drain about two-thirds of the slag after tapping, and adddolomite then rock the furnace for about 3 minutes.Formation of the dense MgO layer was found to be the majormechanism of slag attack resistance in the slag coat on high carbonMgO brick. Dissolution of dolomite made coats of high meltingtemperatures and protected the bricks, so that the use of burntdolomite is preferred. In addition, gaseous reaction products ofMgO+C resulted in reduction of iron oxide in the slag with MgOenriched, which decreased the corrosion potential of the slag.Fused MgO grains showed better resistance to slag attack thansintered MgO grains, thus remaining protruded which served as ananchor for the slag coating. The use of slag splashing technologiesthat provide selective distribution of the slag coating on the highlyworn region in the furnace lining such as trunnion areas willincrease the BOF lining life.
展开▼
