The oxidation pathway and kinetics of titania slag powders in air were analyzed using differential scanning calorimetry(DSC)and thermogravimetry(TG).The oxidation pathway of titania slag powder in air was divided into...The oxidation pathway and kinetics of titania slag powders in air were analyzed using differential scanning calorimetry(DSC)and thermogravimetry(TG).The oxidation pathway of titania slag powder in air was divided into three stages according to their three exothermic peaks and three corresponding mass gain stages indicated by the respective non-isothermal DSC and TG curves.The isothermal oxidation kinetics of high titania slag powders of different sizes were analyzed using the ln-ln analysis method.The results revealed that the entire isothermal oxidation process comprises two stages.The kinetic mechanism of the first stage can be described as f(α) = 1.77(1-α) [-ln (1-α)]^((1.77-1)/1.77),f(α)= 1.97(1-α) [-ln (1-α)]^((1.97-1)/1.97),and f (α) = 1.18(1-α) [-ln (1-α)]^((1.18-1)/1.18).The kinetic mechanism of the second stage for all samples can be described as f (α)=1.5(1-α)^(2/3)[1-(1-α)^(1/3)]^(-1).The activation energies of titania slag powders with different sizes(d_(1)<0.075 mm,0.125 mm<d_(2)<0.150 mm,and 0.425 mm<d_(3)<0.600 mm)for different reaction degrees were calculated.For the given experimental conditions,the rate-controlling step in the first oxidation stage of all the samples is a chemical reaction.The rate-controlling steps of the second oxidation stage are a chemical reaction and internal diffusion(for powders d_(1)<0.075 mm)and internal diffusion(for powders 0.125 mm<d_(2)<0.150 mm and 0.425 mm<d_(3)<0.600 mm).展开更多
The desulphurizing reaction of the blast furnace low titania slag under the condition of no external agitation is confirmed to be of a first order. The controlling step is the diffusion of S in slag. The measures to a...The desulphurizing reaction of the blast furnace low titania slag under the condition of no external agitation is confirmed to be of a first order. The controlling step is the diffusion of S in slag. The measures to accelerate the rate of desulfurization are approached.展开更多
The effects of additive agents and growth behavior of perovskite phase as well as temperature change of slag at semi industry scale test were studied. The results show that the increase of steel slag does good to tita...The effects of additive agents and growth behavior of perovskite phase as well as temperature change of slag at semi industry scale test were studied. The results show that the increase of steel slag does good to titania enrichment, however, it isn’t useful for the growth and coarsening of the perovskite phase. The additive Si-Fe powder can promote titania enrichment and make perovskite phase grow up easily. While air is blown into the molten slag, the reduced components in slag are oxidized and the released heat raises the temperature of slag.展开更多
Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel （ MgAl2O4 ） ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted u...Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel （ MgAl2O4 ） ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted using a static crucible test. The effect of the TiO2 addition on the slag resistances of the lightweight corundum -spinel castables was investigated through SEM, EDS and Fact- Sage@ software, etc. h was found that TiO2 additi,ve t,vmoted the sintering degree of the castables, deereased the average pore .size, the apparent porosity, and the contact area between the casmbles and slag, and then en- hanced the corrosion resistance. However, TiO2 additive decreased the viscosity of the penetrated .slag simultane- ously, and then deteriorated the penetration resistance.展开更多
基金This work was financially supported by the National Key Research and Development Program of China(No.2018YFC1900500)Graduate Research and Innovation Foundation of Chongqing,China(No.CYB17002).
文摘The oxidation pathway and kinetics of titania slag powders in air were analyzed using differential scanning calorimetry(DSC)and thermogravimetry(TG).The oxidation pathway of titania slag powder in air was divided into three stages according to their three exothermic peaks and three corresponding mass gain stages indicated by the respective non-isothermal DSC and TG curves.The isothermal oxidation kinetics of high titania slag powders of different sizes were analyzed using the ln-ln analysis method.The results revealed that the entire isothermal oxidation process comprises two stages.The kinetic mechanism of the first stage can be described as f(α) = 1.77(1-α) [-ln (1-α)]^((1.77-1)/1.77),f(α)= 1.97(1-α) [-ln (1-α)]^((1.97-1)/1.97),and f (α) = 1.18(1-α) [-ln (1-α)]^((1.18-1)/1.18).The kinetic mechanism of the second stage for all samples can be described as f (α)=1.5(1-α)^(2/3)[1-(1-α)^(1/3)]^(-1).The activation energies of titania slag powders with different sizes(d_(1)<0.075 mm,0.125 mm<d_(2)<0.150 mm,and 0.425 mm<d_(3)<0.600 mm)for different reaction degrees were calculated.For the given experimental conditions,the rate-controlling step in the first oxidation stage of all the samples is a chemical reaction.The rate-controlling steps of the second oxidation stage are a chemical reaction and internal diffusion(for powders d_(1)<0.075 mm)and internal diffusion(for powders 0.125 mm<d_(2)<0.150 mm and 0.425 mm<d_(3)<0.600 mm).
文摘The desulphurizing reaction of the blast furnace low titania slag under the condition of no external agitation is confirmed to be of a first order. The controlling step is the diffusion of S in slag. The measures to accelerate the rate of desulfurization are approached.
基金Project(50234040) supported by the National Natural Science Foundation of China
文摘The effects of additive agents and growth behavior of perovskite phase as well as temperature change of slag at semi industry scale test were studied. The results show that the increase of steel slag does good to titania enrichment, however, it isn’t useful for the growth and coarsening of the perovskite phase. The additive Si-Fe powder can promote titania enrichment and make perovskite phase grow up easily. While air is blown into the molten slag, the reduced components in slag are oxidized and the released heat raises the temperature of slag.
基金The National Natural Science Foundation of China(Grant No.51302201)
文摘Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel （ MgAl2O4 ） ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted using a static crucible test. The effect of the TiO2 addition on the slag resistances of the lightweight corundum -spinel castables was investigated through SEM, EDS and Fact- Sage@ software, etc. h was found that TiO2 additi,ve t,vmoted the sintering degree of the castables, deereased the average pore .size, the apparent porosity, and the contact area between the casmbles and slag, and then en- hanced the corrosion resistance. However, TiO2 additive decreased the viscosity of the penetrated .slag simultane- ously, and then deteriorated the penetration resistance.
基金the National Natural Science Foundation of China(No.52004342)Innovation-driven Project of Central South University,China(No.150240015)Natural Science Fund for Outstanding Young Scholar of Hunan Province,China(No.2021JJ20065).
基金The National Natural Foundation of China(51402143)Key Project in the National Science and Technology Pilar Program During the Twelfth Five-year Plan Period(2012BAB06B00)
基金Project(FMRU2007K10)supported by the Open Research Fund of Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,China
