Numerical Simulation On Distribution Of Titanium On The Hearth Wall For Titanium-bearing Materials Through Tuyere

It is well recognized that the campaign of blast furnace is mainly restricted by the erosion of hearth refractories.The production practice of blast furnace have shown that adding TiO2-containing materials into the blast furnace could form a protective layer in eroded regions of the hearth.In recent years titanium-bearing materials through tuyere is applied in some iron and steel industries to directionally maintain the eroded hearth of blast furnace.However,there is not all cases can obtain the expected results.The reason may be that the mechanism of protecting blast furnace lining with titanium-bearing has been investigated clearly but the precipitation and distribution regularity of titanium in the hearth wall have not yet been revealed clearly.Successful experience of some blast furnace is difficult to be used for other,because there are many differences about working state and erosion situation for different blast furnace.In the current work,computational fluid dynamics and thermal equilibrium condition of titanium compound in hot metal is proposed to build model of distribution of titanium in the hearth wall.The effect of different injection parameters and fluctuation of blast furnace on distribution of titanium in the hearth wall is investigated and the change of distribution is also discussed in tapping process.In order to exploit the advantage of titanium-bearing materials through tuyere and extend hearth campaign,the relationship between the titanium distribution and blast furnace protection is discussed preliminarily.The conclusions are as follows.(1)When injecting titanium-bearing materials through single tuyere is applied,distribution of titanium makes a great difference in different injection position.The maximum mass fraction of titanium compound in elephant foot curve increases and the deviation between titanium carbide distribution area and injection position decreases when injection position locates away from the taphole.When injecting titanium-bearing materials through double tuyeres is applied,the difference of titanium distribution area is not obvious with injection through single tuyere.There will be a part of the overlap region of titanium carbide in elephant foot erosion area.Therefore,the optimum position should be determined by calculation results under comprehensive consideration about the location of erosion area and taphole.And injecting titanium-bearing materials through multi-tuyere could be applied.(2)When injecting titanium-bearing materials in the same position for different injection amounts,the distribution area is similar.Concentration of titanium carbide in the hearth sidewall increases with initial concentrate increases.And the maximum concentrations locates in the same area in the curve of elephant foot erosion area,the values are in proportion of initial concentrates.The protection effect will be enhanced with the injection amounts increase appropriately.(3)The different deadman condition has obvious effect on concentration of titanium carbide.The distribution range of titanium carbide is closer the taphole and the concentration is little when floating heights and radius is smaller.Concentration of titanium carbide increases with the permeability increases.Therefore,the size of deadman should be clearly recognized to attain expected effect of protection when titanium-bearing materials injection through tuyere is applied.And the hearth should be kept a good permeability to reduce erosion and attain good effect of protection.(4)In tapping process,the distribution range and concentration of titanium carbide increases with the decline of slag-iron interface.Each effect of various factors should be comprehensively considered.In the later of tapping process,the distribution range of titanium carbide enlarges and the maximum concentration increases.Therefore,it is easier to attain good effect of protection in the later of tapping.(5)The concentration of titanium carbide decreases and distribution is closer the taphole with the productivity increases.It shows that high productivity is not conducive to attain good effect of protection.