A model for estimating the rate constant between CO_2-CO gas and molten slag containing iron oxides using optical basicity

A simple model for estimating the rate constant between CO2-CO gas and molten slag containing iron oxides was developed using optical basicity only. In this model, the temperature dependence of the rate constant can be described by the Arrhenius law, and the activation energy can be expressed with a linear function of the slag＇s optical basicity. The model was applied to some molten slag systems, such as FeO, FeO-CaO, FeO-SiO2, FeO-Na2O, FeO-CaO-SiO2, FeO-SiO2-P2O5, FeO-SiOE-Na2O, and FeO-CaO-SiOE-P2O5. A comparison between the predicted results and measured data showed that the model worked well.

Model for Evaluating Density of Molten Slag With Optical Basicity

A new model is proposed to estimate the density of molten slag, in which the temperature dependence of density is described by Arrhenius Law with the activation energy expressed as the linear function of optical basicity. Successful applications to the density calculations of CaO-Al2 O3-SiO2 and Al2 O3-CaO-MgO-SiO2 slag systems show that this formula can give a good description of composition and temperature dependence of density for molten slags. It is also found that the ionic band percentage of M-O band in MOx oxide is the intrinsic origin of the phenomenon that the slag with a high optical basicity has a large sensitivity to temperature.

Correlation between the Sulphide Capacity Index and the Slag Basicity

The relationships between the sulphide capacity index and the optical basicity, the mole fraction of oxygen ion and the Bell's ratio were investigated based on extensive lab scale equilibrium and industry scale quasi-equilibrium experimental data in the temperature range of 1300 1600℃. Although the sulphide capacity index has good relations with different representations of slag basicity. according to the data obtained under the lab scale equilibrium experimental conditions,the similar relations do not exist according to the data obtained under the industry scale quasi-equilibrium experimental conditions. So it is concluded that the sulphide capacity index, which has been considered as a measure of the slag basicity. can not be used for virtually all oxide slags of interest in the field of ironmaking and steelmaking.

Dephosphorization Thermodynamics of Crude Steel Using CaO-Based Flux

The experiments were carried out at 1 175-1 450 ℃ to study the phosphorus distribution ratio between molten Ca O-based slags and carbon saturated hot metal. The phosphate capacity of the slags and the activity coefficient of PO2. 5were calculated from the phosphorus distribution ratio. The effect of addition of Ca F2 and / or Ca Cl2 on the thermodynamic properties of slags was discussed. The correlation of optical basicity with phosphate capacity of slags was studied,and the dephosphorization ability of Ca O-based fluxes with various additives was compared with the results from different studies.

A new model for evaluating the electrical conductivity of nonferrous slag

Electrical conductivity of molten slag is an important physicochemical property for designing the refming process in electric smelting furnaces. Though conductivities of many slag systems have been measured, the quantitative relationships of conductivity with slag composition and temperature are still very limited. In this article, the Arrhenius law was used to describe the experimental data of conductivities for CaO-MgO-Al2O3-SiO2, CaO-Al2O3-SiO2, CaO-MnO-AlEO3-SiO2, as well as CaO-MgO-MnO- Al2O3-SiO： systems, and it is found that activation energy can be expressed as a linear function of the content of components, where the optical basicity of slag must be within the range of 0.58 to 0.68.

Luminescence Characteristics of Ce^(3+) Doped Ca-Al-Ba Glass

The Al-Ca-Ba glass system with good chemical durability was firstly investigated as the scintillators host. Luminescence properties of Ce3＋ ions in this glass were studied, and obvious red shift and larger stokes shift with respect to others system were investigared. The excellent physical property such as high density and large refractive index implies this glass as an important material for the high quality scintillating fiber.

Water Vapour Solubility in Tundish Slags

In the present work,the solubility of water vapour in tundish slag has been studied in the temperature range from 1 400 C to 1 600 C by a thermogravimetric technique.The water vapour capacity of the slags was calculated and compared with the data from earlier studies.The results confirm that the solubility of water vapour in slags increases with increasing water vapour pressure.The relation between the two parameters obeys Sievert’s law.For slags with optical basicities from 0.5 to 0.8,a regression equation was obtained to express the relation between the water vapour capacity and optical basicity of slags.A tundish slag system with the desired properties can be designed according to the correlations between the optical basicity and various capacities of slags.

Synthesis of praseodymium trioxide doped lead-boro-tellurite glasses and their optical and physical properties

This paper presents the influence of TeO_(2) on the optical and physical properties of rare earth ion Pr^(3+) doped 75PbO-(24-x)B_(2)O_(3-x)TeO_(2)-1Pr_(2)O_(3) glass matrix.Using the absorption coefficient measurements,optical band gap energies of the studied glasses are estimated.Oxide ion polarizability,refractive index,optical basicity,reflection loss and transmission coefficient are discussed and reported for the investigated glasses.Physical parameters like the optical dielectric constant,polaron radius,interatomic separation,molar refraction and the metallization criterion are also studied through molar density and molar volume.The FTIR analysis reveals the shift of the band appearing at 1029 to 870 cm^(-1) because of the high concentration of PbO(75 mol% in the present glass)in the matrix.The Pb-O-B linkage is considered to be the important in the network structure of these glasses.For the present glasses metallization parameter values are<1.The polarizability values are high but decrease with increasing value of TeO_(2) concentration.This may be due to densification of restricted or localized states caused by the creation of dangling bonds.

Distribution ratio of sulfur between high alumina slag and carbonsaturated iron

High alumina slag is widely found in pyrometallurgical extractions of ferronickel,ferrochromium,and platinum group metals.The effects of MgO,Al_(2)O_(3),and CaO/SiO_(2) on the sulfur distribution ratio between high-alumina CaO–SiO_(2)–MgO–Al_(2)O_(3) slag and carbon-saturated iron were investigated.The slag consisted of Al_(2)O_(3) content in the range of 27.61–40.00 wt.%,CaO/SiO_(2) ratio of 0.8–1.1,and MgO content of 8–16 wt.%.The theoretical liquid areas of CaO–SiO_(2)–MgO–Al_(2)O_(3) slag were analyzed through the phase diagrams.The sulfur distribution ratio was measured via the slag–metal equilibrium technique at 1500ºC.It was observed that the sulfur distribution ratio increased with higher MgO content and higher CaO/SiO_(2) ratio largely due to the increase in free O^(2-)ions and the decrease in activity coefficient of sulfur ion in slag,but slightly decreased with the increasing Al_(2)O_(3) content because of the decrease in free O^(2-).

Calculation and Analysis of Sulfide Capacities for CaO-Al_2O_3-SiO_2-MgO-TiO_2 Slags

The empirical models of sulfide capacity calculated by traditional optical basicity do not consider the charge compensation of alkaline metal ions to AP＋ in the molten slags, so that the deviations between the calculated values and measured ones of sulfide capacity are inevitable. The relation between sulfide capacity and the corrected optical basicity put forward by Mills considering the charge compensation was investigated. Combined with the relation be- tween sulfide capacity and temperatures, a novel and accurate calculation model of sulfide capacity was proposed, which was applied to calculate the sulfide capacities of CaO-Al2 O3-SiO2-MgO and CaO-Al2 03-SiO2-MgO-TiO2 sys-tems, where the sum of the CaO and MgO concentrations in the slags must be not lower than the Al2O3 concentra tion. It was also found that the calculated values were in a good agreement with the measured values, and the mean deviations were 2.57% and 2.65%, respectively.

Measuring and Modeling of Density for Selected CaO-MgO-Al_2O_3-SiO_2 Slag With Low Silica

The densities of the selected quaternary CaO-MgO-Al2O3-SiO2 slag with low silica were measured by the Archimedean method in a wide temperature range from 1773 to 1 873 K. Nine different slag compositions were chosen based on three diffel：ent levels of CaO content and three different levels of SiO2 content. WM,O was equal to 7. 0%. Wcao were varied from 40.04% to 50.64%, for wsO2 =10.25%-20. 70%. The effects of temperature, SiOz content and optical basicity were studied. It is shown that density decreases approximately linearly with an increase in temperature. Under the same CaO content, the density decreases with increasing of SiOz content, and increases with optical basicity increasing. Based on the experimental data as the boundary of the homogenous phase region predicated by FACTSAGE software, the mass triangle model is used to calculate the density of selected limited homogenous phase region. The results showed that the mass triangle model works well.