四元体系KCl-K2SO4-KBO2-H2O在298.15 K的Pitzer模型研究

在Pitzer电解质溶液理论的基础上采用两种模型计算了KCl-K₂SO₄-KBO₂-H₂O体系及其子体系的溶解度。模型I假设溶液中只有一种硼物种B(OH)₄^-,模型II假设溶液中有4种硼物种,分别对应于B(OH)₃、B(OH)₄^-、B₃O₃(OH)₄^-和B₄O₅(OH)₄^2-。模型I与模型II的溶解度计算结果接近,且与实验值吻合较好。采用模型II计算了上述体系溶液中的硼物种和OH^-的浓度。各硼物种的浓度主要受溶液中总硼浓度的影响,而很少受KCl和K₂SO₄的影响。计算结果说明在计算偏硼酸钾溶液体系溶解度时,可近似认为溶液中硼物种只有B(OH)_4...     

蒸发岩成因的物理化学研究

海水体系相平衡的研究是蒸发岩矿床成因研究的物理化学基础。本文简要回顾了我国在这方面的研究成果，包括对黄海海水、南海海水的等温蒸发实验，对潜江凹陷蒸发岩形成机理的研究，对蒸发岩变质作用的研究，对杂卤石形成条件的研究以及Ｋ、Ｎａ、Ｍｇ／Ｃｌ－Ｈ＿２Ｏ四元体系多温计算系统的研制等等。这些工作都是以物理化学理论和实验为基础，探讨蒸发岩矿床的形成及演化机理。文中还介绍了近年来由著名物理化学家Ｋ．Ｓ．Ｐｉｔｚｅｒ提出的多组分电解质溶液理论，并简要介绍了Ｐｉｔｚｅｒ理论在海水体系相平衡研究中的应用。     

The solubility and behaviour of acid gases in the marine aerosol

The following Henry's law constants (K _H/mol²kg^-2atm^-1) for HNO₃ and the hydrohalic acids have been evaluated from available partial pressure and other thermodynamic data from 0°–40°C, 1 atm total pressure: HNO ₃ , 40°C–5.85×10⁵; 30°C–1.50×10⁶; 25°C–2.45×10⁶; 20°C–4.04×10⁶; 10°C–1.15×10⁷; 0°C–3.41×10⁷. HF, 40°C–3.2; 30°C–6.6; 25°C–9.61; 20°C–14.0; 10°C–32.0; 0°C–76. HCl, 40°C–4.66×10⁵; 30°C–1.23×10⁶; 25°C–2.04×10⁶; 20°C–3.37×10⁶; 10°C–9.71×10⁶; 0°C–2.95×10⁷. HBr, 40°C–2.5×10⁸; 30°C–7.5×10⁸; 25°C–1.32×10⁹; 20°C–2.37×10⁹; 10°C–8.10×10⁹; 0°C–3.0×10¹⁰. HI, 40°C–5.2×10⁸; 30°C–1.5×10⁹; 25°C–2.5×10⁹; 20°C–4.5×10⁹; 10°C–1.5×10¹⁰; 0°C–5.0×10¹⁰. Simple equilibrium models suggest that HNO₃, CH₃SO₃H and other acids up to 10x less soluble than HCl displace it from marine seasalt aerosols. HF is displaced preferentially to HCl by dissolved acidity at all relative humidities greater than about 80%, and should be entirely depleted in aged marine aerosols.     

A Gibbs–Pitzer function for high-salinity seawater thermodynamics

A high-salinity Gibbs function for seawater is derived from Pitzer equations of the sea salt components, in conjunction with the 2003 Gibbs function of seawater for low salinities. Various properties, computed from both formulations by thermodynamic rules, are compared with each other, and with high-salinity measurements. The new Gibbs–Pitzer function presented in this paper is valid in the range 0–110 g kg⁻¹ in absolute salinity, −7 to +25 °C in temperature, and 0–100 MPa in applied pressure. The formulation is expressed in the International Temperature Scale 1990 (ITS-90), and is consistent with the International Standard for Fluid Water (IAPWS-95), and with the 2005/2006 equations of state of ice Ih.     

Na+,K+,Mg2+/NO3-,Cl-,SO42- -H2O体系25℃热力学模型和溶解度预测Ⅰ:六元体系所需的Pitzer参数

在致力于Clegg-Pitzer模型和局部组成模型及其温度效应的研究基础,进一步结合含硝酸盐混合电解质溶液热力学的实验和理论研究,深入探讨了Pitzer模型对Na+,K+,Mg2+/Cl-,SO42-,NO3--H2O体系的适用性和各种应用。     

Na+,K+,Mg2+//NO3-,Cl-,SO42--H2O体系25 ℃热力学模型和溶解度预测Ⅲ:四元体系K+,Mg2+//NO3-,SO42--H2O的Pitzer混合参数及其应用

前两文我们获得并讨论了用于六元体系溶解度计算合理的单独电解质Pitzer参数,及Na+,K+∥Cl-,NO3--H2O四元体系混合参数和它们的应用。此次报道对K+,Mg2+∥NO3-,SO42--H2O四元体系混合参数的研究及其在体系溶液热力学性质和溶解度预测中的应用。     

Na^＋，K^＋，Mg^＋∥NO3^-，Cl^-，SO4^2-H2O体系25℃热力学模型和溶解度预测Ⅲ：四元体系K^＋，Mg^2＋／NO3^-，SO4^2——H2O的Pitzer混合参数及其应用

前两文我们获得并讨论了用于六元体系溶解度计算合理的单独电解质Pitzer参数,及Na^＋,K^＋/Cl^-,NO3^-H2O四元体系混合参数和它们的应用。此次报道对K^＋,Mg^2＋//NO3^-,SO4^2-H2O四元体系混合参数的研究及其在体系溶液热力学性质和溶解度预测中的应用。     

298.15K下Li2SO4-Li2B4O7-H2O体系热力学性质的等压研究

用等压法研究了Li2SO4-Li2B4O7-H2O体系的Li2SO4和Li2B4O7纯盐水溶液(离子强度范围分别为0.3577~5.6378 mol.kg-1及0.1747~2.4497mol.kg-1)及混合盐水溶液(离子强度范围为0.3118~5.5248mol.kg-1)的渗透系数,并获得了该体系渗透系数随离子强度的变化规律。用实验数据以最小二乘法求取了Li2SO4和Li2B4O7的纯盐参数及混合盐参数,拟合的标准偏差分别为0.0072和0.0188。用Pitzer模型计算的渗透系数与实验值结果取得一致,表明该模型能够较好的描述25℃下Li2SO4-Li2B4O7-H2O体系的热力学性质。实验对完善含锂、硼盐湖卤水体系的热力学模型和盐湖资源的综合开发具有重要意义。     

硫酸钠亚型富锂卤水25℃等温蒸发过程的计算机模拟

我国青藏高原上分布有许多盐湖,其中扎布耶等碳酸盐型盐湖、东台吉乃尔等硫酸镁亚型盐湖是著名的富锂盐湖,已成功开发生产出碳酸锂产品。青藏高原上还有许多硫酸钠亚型盐湖,其卤水锂浓度高,钾、镁、硼等有用成分丰富。针对这些盐湖资源,目前尚未进行开发利用研究。这些卤水的等温蒸发实验研究,是必不可少的关键工作之一。本文使用我们由Pitzer电解质溶液理论建立的Li+,Na+,K+,Mg2+/Cl-,SO24--H2O体系的热力学模型,对25℃下几种硫酸钠亚型富锂卤水等温蒸发过程进行了计算机模拟,预测蒸发过程中盐类矿物的析出顺序、卤水组成变化规律、钠、钾、镁、锂盐的饱和点,并在此基础上进行卤水蒸发过程物料平衡关系的理论计算等。本文对西藏3种硫酸钠亚型卤水和国外2种硫酸钠亚型卤水25℃等温蒸发过程进行了模拟。其析盐顺序的特点是:在第一个矿物石盐饱和析出后,接着析出的含钾矿物是钾芒硝,而不是钾镁矾类矿物。其后钾盐则会以钾岩盐形式析出。锂盐饱和后则主要以复盐Li2SO4.K2SO4形式析出。美国银峰卤水的模拟结果与实验蒸发过程完全一致,并给出其继续蒸发时的析盐状况。另4种硫酸钠亚型卤水的模拟结果不仅可以作为未来实验研究的基本参考和注意点,同样也可作为其盐田设计和工艺安排的基本理论依据。本文研究为该类型卤水资源综合开发利用工艺路线的确立提供理论参考。     

Thermodynamic Properties of Brucite Determined by Solubility Studies and Their Significance to Nuclear Waste Isolation

Solubility experiments were conducted for the dissolution reaction of brucite, Mg(OH)₂ (cr): Experiments were conducted from undersaturation in deionized (DI) water and 0.010–4.4 m NaCl solutions at 22.5°C. In addition, brucite solubility was measured from supersaturation in an experiment in which brucite was precipitated via dropwise addition of 0.10 m NaOH into a 0.10 m MgCl₂ solution also at 22.5°C. The attainment of the reversal in equilibrium was demonstrated in this study. The solubility constant at 22.5°C at infinite dilution calculated from the experimental results from the direction of supersaturation by using the specific interaction theory (SIT) is: with a corresponding value of 17.0 ± 0.2 (2σ) when extrapolated to 25°C. The dimensionless standard chemical potential (μ°/RT) of brucite derived from the solubility data in 0.010 m to 4.4 m NaCl solutions from undersaturation extrapolated to 25°C is −335.76 ± 0.45 (2σ), with the corresponding Gibbs free energy of formation of brucite, , being −832.3 ± 1.1 (2σ) kJ mol⁻¹. In combination with the auxiliary thermodynamic data, the is calculated to be 17.1 ± 0.2 (2σ), based on the above Gibbs free energy of formation for brucite. This study recommends an average value of 17.05 ± 0.2 in logarithmic unit as solubility constant of brucite at 25°C, according to the values from both supersaturation and undersaturation. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under Contract DE-AC04-94AL85000.