钒在铜液中活度系数的实验研究

在1 673～1 873 K温度范围以及不同氧分压条件下,利用固态V2O3与液态Cu进行高温化学平衡实验,测得了V在Cu液中活度系数,其中氧分压通过CO/CO2(g)进行控制.由于V2O3中存在氧的非化学计量性,采用(V2O3)S.S.的固溶体吉布斯自由能模型对V在Cu液中活度系数进行修正,从而得到V在Cu液中的Henry常数与温度的关系式.     

硅酸盐熔体或冶金熔渣中二氧化硅的活度研究述评

本文系统地分析了几十年来各国学者采用不同的测试和研究方法对诸多的硅酸盐熔体中二氧化的热力学性质的研究结果，结合有代表性的研究工作评价一该研究领域中典型的研究测试方法，其中重点评价了化学平衡法和原电池电动势法用于此类研究的利弊。     

FeO—Fe2O3—CaO—ZnO—SiO2系熔渣中ZnO的活度系数

用试验的方法测定了符合铅冶炼厂实际的人造熔渣中各组成含量变化时 ZnO 的活度系数,并得出回归方程。高 CaO 渣对脱锌有利,而 Na_2O 的烟化脱锌效果更好。     

熔渣中PbO,ZnO活度的研究现状

叙述硅酸盐渣系ＰｂＯ、ＺｎＯ活度的研究现状，分析了某些方法的不足，指出了今后研究方向。     

Al-Mg-Sc合金中组元活度及活度相互作用系数

以 Miedema二元合金生成热模型及 Toop方程为基础 ,利用元素的基本性质 ,计算了 1 0 73K下 Al-Mg- Sc三元合金溶液中组元的活度及组元间活度相互作用系数。结果表明 ,lnγ0Mg=- 0 .0 0 54;εMg Mg=0 .0 0 2 2 ;εSc Mg=εMg Sc=0 .0 2 8;ρMg Mg=- 0 .0 0 1 3;ρSc Mg=0 .0 1 5;ρMg Sc Mg =- 0 .0 75。     

铁液中硫活度的测定方法探讨

以CaS(1%Y2S3)作固体电解质,W/WS2为参比电极组成化学传感器,对碳饱和铁液中硫的活度进行了测定,实验证明:CaS(1%Y2S3)固体电解质作为定硫传感器是可行的.     

有色合金中组元活度相互作用系数的模型计算

在Ｍｉｅｄｅｍａ二元合金生成热模型基础上，采用规则溶液一级近似理论、自由体积理论以及Ｔｏｏｐ几何模型，建立了三元系中组元活度相互作用系数的计算模型。计算结果与实验值对比效果良好。     

Mn—C—Si系锰基熔体的活度与自由能计算

实验测定了１６７３Ｋ时Ｍｎ－Ｃ－Ｓｉ系熔体中Ｓｉ对Ｃ的溶解度的影响，计算得到锰基熔体中一阶和二阶活度相互作用系数以及Ｃ在Ｍｎ液中的标准溶解自由能值。     

改进的KF模型在SiO2-CaO-MnO熔渣体系中的应用

基于KF模型和Gaye模型,得到改进的KF模型,并推导出三元体系的表达式。把该模型应用到三元SiO2-CaO-MnO熔渣体系,通过对二元系研究得到模型参数,从而可计算三元系中组元的活度。结果表明计算结果与实验结果的相对偏差分别为：SM＊nO1 823K=19.3%,SM＊nO1 773K=28.1%。表明该理论在SiO2-CaO-MnO熔渣体系的应用是可行的。     

钢铁冶炼渣的处理利用难点分析

为促进熔炼渣的显热回收、降低钢铁冶炼能耗,提高熔炼渣的利用率和经济性,通过分析钢铁厂熔渣的处理和利用难点,提出了熔渣调质及泡沫化处理的干法粒化方法,通过引入金属铁提高熔渣的导热系数、熔渣泡沫化改善粒化效果,为解决干法粒化及熔渣利用面临的难题提供了思路,并对干法粒化的研究方向给出了建议。     

Activity of VO1.5 in CaO‐SiO2‐MgO‐Al2O3 Slags at Low Vanadium Contents and Low Oxygen Pressures

In the present work, the gas‐slag equilibration technique was employed for the measurement of the thermodynamic activity of vanadium oxide. The vanadium‐containing slag kept in a platinum crucible was equilibrated with a gas mixture of CO, CO₂ and Ar, with well‐defined oxygen partial pressure at a pre‐determined temperature. The slag sample was quenched and the composition of the final slag was determined by chemical analysis. From the value of the oxygen partial pressure, the thermodynamic activity of VO_1.5 could be calculated using the value for the activity of vanadium in V‐Pt alloy. The measurements were carried out in the temperature range 1823～1923K and the oxygen partial pressures employed were 10^‐3, 10^‐4, 10^‐5 Pa. The present results show that the activity of vanadium(III) oxide in slag exhibits a negative deviation from ideality in the present composition range. With increasing basicity of the slag, the final content of vanadium oxide in the slag was found to show an initial increase followed by a constant content. The activities of vanadium(III) oxide did not exhibit any significant change with increasing temperature. The activity coefficient of vanadium(III) oxide decreased sharply with slag basicity approximately up to a basicity of 1, beyond which it showed a near–constant value. Increase in basicity was found to cause a change in the distribution of vanadium between the slag and the alloy phases even though this effect was less pronounced. From the present results, a mathematical relationship for estimating the vanadium content in slag for a given activity of vanadium in the molten metal phase was developed.     

Equilibrium between Slag and Molten Iron in the Direct Alloying of Steel with Nb2O5-Bearing Slag

Equilibrium between slag and molten iron at 1600℃ was investigated for the direct alloying of steel with Nb₂O₆-bearing slag. The activity of niobium oxide in the slag was measured. The α_Nb2O5 is in the range of 10^-2-10^-4. Theδ_Nb2O5 is ranged in 10⁰-10^-2.Niobium partition decreases with the increase of[Si]% and CaO/SiO₂. When α_[0] and ΣFeO decrease, niobium partition decreases too. The δ_Nb2o5 and the ratio of γ_siO2 to γ_Nb2O5 decrease with the incre-ase of slag basicity. The suitable thermodynamic conditions in direct alloying of steel with Nb2O5-bearing slag have been found.     

The Thermodynamics of Some Transition Metals in Molten Slags

In the present paper, the thermodynamic behaviour of transition metals, such as Cr, Ti, Nb and V in molten slags is systematically analysed based on a literature survey. These metals exist in molten slags with multi valences. Oxygen partial pressure, slag basicity, total content of each transition metal, content of each component in slag, and temperature are the influential factors on their thermodynamic properties in molten slags. Higher basicity and strong oxidative atmosphere are generally favourable for the stable existence of transition‐metal ions with higher oxidation states. Temperature is a factor that is less influential than the above‐mentioned ones. For a transition metal in molten slag, the concentration ratio of ions of different valences depends on the activity coefficient ratio of their oxides. The present paper summarizes the activity studies regarding the transition metal oxides in various molten slags. For chromium and titanium oxides, information on CaO? SiO₂ based systems is involved. For titanium oxides, its thermodynamic behaviour in MnO? SiO₂ based slags is introduced. For niobium and vanadium, the information in Na₂O? SiO₂, CaO? CaF₂? SiO₂ systems is provided. Thermodynamic studies are described for Nb₂O₅? MnO? SiO₂ molten slag equilibrated with liquid iron at 1828 K.     

碳饱和铁液中钛溶解度测定探讨

介绍了碳饱和铁液中钛溶解度的不同测定方法,对测定结果进行了比较,分析了可能存在的误差原因;当利用含钛物料护炉时,铁液中含钛量应控制在一定的范围内,从而为高炉冶炼钒钛磁铁矿提供指导．     

高碳铁液中的Al-C-O平衡

为了促进铁水脱硫,在铁水预处理过程中加Al脱氧,由于铁水中C含量很高,Al、C同时存在于铁水中.研究了铁水中生成Al₄C₃的判定条件,分析了Al₄C₃的生成对Al脱氧的影响.利用热力学方法,计算了a_Al⁴·a_C3的值,从而对Al-C-O三相平衡进行了分析,通过得出的a_Al⁴·a_C3值绘制了Al-C平衡曲线,并进行了相关讨论,以确定Al₄C₃的生成范围.     

Enthalpy interaction coefficients at constant activity and their applications to the enthalpy of carbon in liquid iron

Measurements of thermodynamic properties are often performed at saturation of one of the solutes. Exploitation of these data has given rise to a set of free energy interaction coefficients at constant activity of one solute which are different from those more familiar coefficients which apply at infinite dilution of all solutes. In the present contribution, enthalpy and entropy interaction coefficients at constant activity of one solute are defined. Their relationships to other functions and coefficients of more general usage are established. The use of these relationships is illustrated by showing how the temperature dependence of the effects of various solutes on the solubility of graphite in liquid iron allows the evaluation of various heats of solution and enthalpy interaction coefficients.     

Application of the quasi-random lattice model to rare-earth halide solutions for the computation of their osmotic and mean activity coefficients

This work dealt with the computation of the mean activity coefficients of rare-earth halide aqueous solutions at 25℃, by means of the Quasi Random Lattice（QRL） model. The osmotic coefficients were then calculated consistently, through the integration of the Gibbs-Duhem equation. Using of QRL was mainly motivated by its dependence on one parameter, given in the form of an electrolyte-dependent concentration, which was also the highest concentration at which the model could be applied. For all the electrolyte solutions here considered, this parameter was experimentally known and ranged from 1.5 to 2.2 mol/kg, at 25 ℃.Accordingly, rare- earth halide concentrations from strong dilution up to 2 mol/kg about could be considered without need for best-fit treatment in order to compute their osmotic and mean activity coefficients. The experimental knowledge about the parameter was an advantageous feature of QRL compared to existing literature models. Following a trend already observed with low charge electrolytes,a satisfactory agreement was obtained with the experimental values for all the investigated rare-earth chlorides and bromides. For the sake of compactness, in this work the considered rare-earth halides were all belonging to the P63/m space group in their crystalline（anhydrous） form.