Study On Properties Of XuanHua Steelworks Titanium-containing Blast Furnace Slag Smelting

With the increase of steel’s output and resource lack,the cost of importing outer mine will increase.So increasing the local mine’s mixed ratio is necessary to reduce producing cost.Xuan Hua is rich in iron concentrate,but most of the powder has certain content of TiO2.Adding too much to sintering or pellets,there will be adverse influence to blast furnace smelting,such as slag bodying,not direct motion,etc,and this problem is caused by the change of slag performances.Slag with 3% and 3~9% contents of titania was researched firstly in slag viscosity,melting temperature and desulfurizing performance.Burden structure was also studied.Combined with field condition,conclusions were obtained as follows:1) In certain condition,with the increase of basicity,slag viscosity reduces,and melting temperature increases.With the increase of titania oxide content,slag viscosity reduces,and melting temperature increases.When content of titania oxide increases to a certain value,slag viscosity and melting temperature hold the line.With the increase of magnesium oxide content,the slag viscosity and smelting temperature present little changes,but melting temperature reduces in low alkalinity,and increases in high alkalinity.2) Slag’s Ls is 11~30.In certain condition,with the increase of basicity,Ls increases.With the increase of titania oxide content,Ls reduces.With the increase of magnesium oxide content,Ls increases.3) According to the performance research of slag,and combining with practice instance of Xuan Steel blast furnace,the basicity of slag is fit to control at 1.15~1.20. Content of titania oxide is lower than 7%.Content of magnesium oxide is 10%~11%.4) Adding block mine and manganese minerals to furnace charge,is a benefit to reduce indissoluble nature,viscosity of slag, and to reduce the formation of TiC,TiN,and Ti(C,N) solid solution. Adding fluorite,is a benefit to reduce viscosity and accelerate desulfurize reaction process,but the addition should be lower than 1%~3%;it is suggested to add 5% block mine and about 3% manganese minerals.