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1.
依据化学中广泛应用的同系线性规律,拟合钙、镁复合化合物标准反应吉布斯自由能之间的线性关系式,然后由3CaO·B2O3和2CaO·B2O3的标准反应吉布斯自由能求得3MgO·B2O3和2MgO·B2O3的标准反应吉布斯自由能,进而基于炉渣结构的共存理论和相图,推导MgO-B2O3二元渣系的热力学计算模型.结果表明:1 460℃时,在浓度为0.45<x(MgO)<0.80的范围内,理论计算的MgO-B2O3渣系的作用浓度N(B2O3)的变化规律与实测活度α(B2O3)是相同的,且拟合较好. 相似文献
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为研究精炼渣中Ce2O3的加入对渣中Al2O3活度的影响,根据炉渣结构离子与分子共存理论和相关相图,建立1500℃下Ce2O3-Al2O3和CaO-Al2O3-Ce2O3渣系作用浓度的计算模型,考察Ce2O3对Al2O3作用浓度的影响。结果表明:对于Ce2O3-Al2O3渣系,当Ce2O3的摩尔分数在0.49左右时,Ce2O3·Al2O3的作用浓度达到最大值0.90,使得Al2O3和Ce2O3的作用浓度均达到较低水平;对于CaO-Al2O3-Ce2O3渣系,模型所计算的Al2O3作用浓度与实测Al2O3活度的变化趋势一致,即Ce2O3含量一定时,随着w(CaO)/w(Al2O3)的增加,Al2O3的作用浓度降低;保持w(CaO)/w(Al2O3)不变,随着Ce2O3含量的增加,Al2O3的作用浓度降低。同时,由计算结果绘出CaO和Ce2O3的等作用浓度线。总之,精炼渣中添加一定量的Ce2O3能够有效地降低Al2O3的作用浓度,这能提高精炼过程中高质量洁净钢中Al2O3的去除速率和精炼渣的精炼效率。 相似文献
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根据炉渣结构的共存理论和相图,推导了CaOB2O3和FeOFe2O3B2O3渣系的热力学计算模型。结果表明:(1)理论计算的CaOB2O3渣系的作用浓度NCaO及NB2O3与实测的活度aCaO及aB2O3一致;(2)理论计算的FeOFe2O3B2O3渣系的氧化能力NFetO与实测的炉渣FetO的活度值相符合。这说明本文提出的热力学计算模型是合理的。 相似文献
4.
基于炉渣结构的共存理论,建立了MnO-SiO2-Al2O3三元渣系作用浓度的计算模型,考察了影响MnO作用浓度的影响因素。结果表明:模型计算所得的MnO作用浓度值NMnO与文献实测值aMnO(exp)非常吻合,且计算精度要高于正规溶液模型获得的计算值aMnO(cal),说明该模型能够反映该渣系的结构本质。利用此模型可以很好地预测Mn/Si脱氧钢的夹杂物成分,为生产高质量的帘线钢提供热力学参考。 相似文献
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基于炉渣结构共存理论,建立1 200~1 300 ℃下CaO-Cu2O-Fe2O3三元渣系组元活度的计算模型,计算并绘制渣中CaO、Cu2O和Fe2O3的等活度曲线,考察碱度B和温度t对组元活度α(CaO)、α(Cu2O)和α(Fe2O3)的影响.结果表明:模型计算值α(Cu2O)与文献实测值α′(Cu2O)吻合程度高,说明模型能较好地反映该渣系的结构本质;α(Cu2O)呈拉乌尔正偏差,在B=1.54时出现最大值,当B>1.54时随着B和t的增大而降低,当B<1.54时趋势正好相反,且受碱度影响更为显著;α(CaO)和α(Fe2O3)分别随CaO和Fe2O3在炉渣中含量的升高而增大,但受温度的影响都不明显.研究结果可用于采用铁酸钙渣系的炼铜新工艺热力学研究. 相似文献
6.
基于离子与分子共存理论,建立了计算二元和三元强电解质水溶液中结构单元或离子对的质量作用浓度的通用热力学模型;同时,采用4种二元水溶液和2种三元水溶液验证该通用热力学模型。通过转换标准态和浓度单位,用所建立的通用热力学模型计算出的298.15K时4种二元水溶液和2种三元水溶液中结构单元或离子对的质量作用浓度和文献中报道的活度值吻合得很好。因此,可采用本研究提出的通用热力学模型计算出的二元和三元水溶液结构单元或离子对的质量作用浓度预报二元和三元强电解质水溶液中组元的反应能力;同样,也可证实本研究提出的通用热力学模型的假设条件是正确和合理的,即强电解质水溶液是由阳离子和阴离子、H2O分子和其他水合盐复杂分子组成的。基于该通用热力学模型计算出的二元和三元强电解质水溶液结构单元或离子对的质量作用浓度严格服从质量作用定律。 相似文献
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Thermodynamic models of calculating mass action concentrations for structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions were developed based on the ion and molecule coexistence theory at 298.15 K. A transformation coefficient is needed to compare the calculated mass action concentration and the reported activity because they are obtained at different standard states and concentration units. The results show that the transformation coefficients between the calculated mass action concentrations and the reported activities of the same structural units or ion couples in RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions change in a very narrow range. The transformed mass action concentrations of structural units or ion couples in RbCl-H2O binary system are in good agreement with the reported activities. The transformed mass action concentrations of RbCl and RbNO3 in RbCl-RbNO3-H2O ternary solution are also in good agreement with the reported activities, aRbCl and , with different total ionic strengths as 0.01, 0.05, 0.1, 0.5, 1.0, 1.5, 2.0, 3.0 and 3.5 mol/kg, respectively. All those results mean the developed thermodynamic model of strong electrolyte aqueous solutions can reflect structural characteristics of RbCl-H2O binary and RbCl-RbNO3-H2O ternary strong electrolyte aqueous solutions and the mass action concentration also strictly follows the mass action law. 相似文献
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ZHANGJian 《稀有金属(英文版)》2002,21(1):43-47
Based on phase diagrams and measured activities, the calculating model of mass action concentrations for heterogeneous melts Ag-Au-Cu was formulated. Calculated results agree with the improved results of recent research work,showing that the model formulated can reflect the structural characteristics of these melts. In this model, without the help of any empirical parameters, only three equilibrium constants are used, hence it is simple, lear, and favorable to the simplification of calculation. 相似文献
10.
NaOH-NaAl(OH)4-Na2CO3-H2O体系活度因子的计算模型 总被引:1,自引:0,他引:1
应用Bromley模型,通过对氢氧化钠、铝酸钠和碳酸钠等溶液体系活度因子的实验数据进行校验与回归分析,获得了各电解质合理的Bromley参数,建立基于Bromley模型的NaOH-NaAl(OH)4-Na2CO3-H2O体系活度因子的计算模型,其适用范围为:质量摩尔浓度分别为m(NaOH)≤8 mol/kg,m(NaAl(OH)4)≤3 mol/kg,m(Na2CO3)≤3 mol/kg且离子强度I≤9 mol/kg.使用该模型和Rard方法计算所得水的活度比较结果表明:该模型正确有效,计算精度较高,各电解质的Bromley参数取值合理;该模型也可用于NaOH-NaAl(OH)4-H2O体系活度因子的计算. 相似文献
11.
以V2O5-H3PO4-en-H2O(en=NH2CH2CH2NH2)体系为例,系统研究了合成工艺与物相形成的关系.结果表明:在其他条件不变的条件下,反应物摩尔比对产物物相组成有明显影响;不同的加料顺序会引起不同的初始反应,但与最终产物的形成和组合无关;充填率对各物相的相对含量有影响,高充填率利于高骨架密度物相的形成;影响水热合成的各因素间存在复杂的关联性. 相似文献
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The thermodynamics equilibrium principle was used to construct the diagrams for the concentration of complex ions (pc) vs pH, the distribution ratio of lead hydroxyl complex ions (αn) vs pH, and the conditional solubility product of Pb(OH)2 vs pH in the Pb2+-H2O system. The relationship between the equilibrium concentration of each kind of lead hydroxyl complex ions in equilibrium with Pb(OH)2(s) and pH value was shown in the system. The minimum solubility of lead is at the pH value of 10.096-10.997. The distribution ratio of each kind of the lead hydroxyl complex ions is determined as a function of the pH value and the total lead concentration ([Pb]T). The diagram for the conditional solubility product, pKSP vs pH, shows that each kind of lead hydroxyl complex ions existing in the system is dependent upon an optimized pH value at the established concentration of [Pb]T, and that pKSP reaches the minimum at the pH value of 10.3-11.2. The results can provide a theoretical basis for removing lead ions from wastewater by the neutralization and hydrolyzation technology. 相似文献
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根据配位化学热力学平衡原理,绘制了Cd^2+-H2O系配合离子浓度pc-pH图、镉羟合配离子分率αn-pH图及Cd(OH)2条件溶度积pKS-pH图。pc-pH图描述了Cd(OH)2(s)溶解平衡时,镉的总离子平衡浓度与pH的关系。当pH为9.84~13.31时,Cd(OH)2的溶解度最小;αn-pH图指出了各种羟合配离子分率与pH关系,每种羟合配离子都对应有其存在的最佳pH范围。Cd(OH)2(s)的条件溶度积pKS-pH图表明:当pH值在9.5~10.5范围内,Cd(OH)2(s)的条件溶度积最小。研究结果可为中和水解法去除废水中镉等技术提供理论依据。 相似文献
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The first-class reciprocal quaternary system H3PO4-K2SO4-K3PO4-H2SO4-H2O has been carefully investigated at 25 and 75°C. Representations have been given using the Jänecke coordinates. Using the established diagrams as a base, a procedure is proposed for preparing specific fertilizers containing potassium and phosphate ions by reacting phosphate rock with aqueous solutions of KHSO4, addition of calculated amounts of water to the reaction mixture, elimination of an insoluble products, and programmed water evaporation. 相似文献
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The phase diagram of the CaO-SiO2-CrOx-MgO-MnO system at moderately reducing oxygen partial pressure was calculated using a commercial thermochemical program and
compared with the phase analysis for converter slags taken from the stainless steelmaking process. It was found that a (Mn,Mg)Cr2O4 solid solution and Ca2SiO4 phase are in equilibrium with the oxidation slags after the oxygen blowing period, which is consistent with thermodynamic
calculations. Furthermore, it could be proposed that the thermodynamic properties of a MgCr2O4-MnCr2O4 binary spinel make it close to an ideal solution. 相似文献