三元体系MgCl2-CO(NH2)2-H2O在25℃时的等温溶度与新相研究

测定了25℃时三元体系MgCl₂-CO(NH₂)₂-H₂O的等温溶度及饱和溶液的折光率和密度,且绘制成溶度图和性质-组成图.在三元体系内形成2个三元化合物新相:MgCl₂·CO(NH₂)₂·4H₂O(记作A)和Mgcl₂·4CO(NH₂)₂·2H₂O(记作B),B为新化合物.三元体系的溶度图由4支单饱和线[对应单饱和固相为MgCl₂·6H₂O、三元化合物A和B、CO(NH₂)₂]组成,这4支单饱和线两两交于3个三元无变点[对应双饱和固相为MgCl₂·6H₂O+A、A+B、B+CO(NH₂)₂].     

Metastable Phase Equilibrium of the Quaternary System Na+, Rb+, Mg2+//Cl--H2O at 298.2 K

The component solubilities, densities and refractive indices of the quaternary system Na⁺, Rb⁺, Mg²⁺//Cl^--H₂O at 298.2 K were measured using an isothermal evaporation method. Based on the gathered data, a metastable phase diagram, a water content diagram, and a density/refractive index vs. composition diagram were constructed. The results show that this system is of a complex type with a double salt rubidium carnallite (RbCl·MgCl₂·6H₂O) formed at 298.2 K. Double salt rubidium carnallite, whose component point locates in its own crystallization zone in the dry salt phase diagram, belongs to congruent double salt at 298.2 K. Accompanied by the double salt that was formed, there are two invariant points in the phase diagram that cosaturated with three salts and an equilibrated solution. The cosaturated salts for the two invariant points are MgCl₂·6H₂O+RbCl·MgCl₂·6H₂O+ NaCl and NaCl+RbCl+RbCl·MgCl₂·6H₂O, respectively. Both invariant points are commensurate invariant points in the evaporation process, and the two invariant points are evaporative dry points. The sizes of the crystalline regions of the salts are in the order of NaCl > RbCl > RbCl·MgCl₂·6H₂O > MgCl₂·6H₂O.     

五元体系LiCl-NaCl-KCl-MgCl2-H2O 25℃时溶度研究和等温蒸发实验

本文首次给出了五元体系LiCl-NaCl-KCl-MgCl₂-H₂O 25℃时的溶度图。讨论了氯化锂对体系中其它盐类的盐析作用。还报道了几个合成卤水在静态条件下的等温蒸发结果。研究表明所得平衡相图可作为此类盐卤析盐顺序的理论依据。     

Isothermal Evaporation of Quaternary System Li^＋, K^＋, Mg^2＋//Cl^--H2O at 348K

The solubilities of the quaternary system Li^＋,K^＋,Mg2^＋//Cl^--H2O were investigated at 348 K via isothermal evaporation.The densities and refractive indices of its equilibrated solution were also determined experimentally.On the basis of the obtained data,the metastable phase diagram,the water content diagram,the diagrams of the density and refractive index against the composition of this quaternary system were constructed.The quaternary system Li^＋,K^＋,Mg^2＋//Cl^--H2O at 348 K belongs to a complex type with the formation of two carnallite double salts,which are potassium carnallite（K-carnallite） and lithium carnallite（Li-carnallite）.There are five salts like potassium chloride （KCl）,lithium chloride monohydrate（LiCl.H2O）,bischofite（MgCl2·6H2O）,K-carnallite（KCl·MgCl2·6H2O） and Li-carnallite（LiCl·MgCl2·7H2O）,seven unvariant curves named AH3,BH2,CH3,DH1,EH1,H1H2 and H2H3,and three invariant points,namely H1,H2 and H3,included in this metastable phase diagram.Comparisons between the stable phase diagram at 298 K and metastable phase diagram at 348 K of this quaternary system show that all the crystalline forms of the salts are not changed,whereas the crystallization areas of salts are changed significantly with temperature.The scope of KCl crystallization increases from 82% to 95% and that of K-carnallite decreases from 15.80% to 0.32% along with the temperature increasing from 298 K to 348 K,respectively.     

四元体系LiCl-KCl-MgCl2-H2O 25℃时等温研究

本文首次报道了四元体系LiCl-KCl-MgCl₂-H₂O 25℃时的溶度和饱和溶液的折光率、密度和粘度值。并给出了体系的相图、溶度面、总氯量面及上述物理性质面。     

四元体系H3BO3-MgSO4-MgCl2-H2O在273.15K的溶解度等温线

作者考察了H₃BO₃-MgSO₄-MgCl₂-H₂O四元体系在273.15±0.05K温度下的溶解度等温线。四元体系共饱和点的液相组成为33.44%(重量)MgCl₃,1.77%MgSO₄和0.65%H₃B0₃。     

Solid-liquid Equilibria in the Quaternary System Na＋, K＋//Br-, B4O72--H2O at 298 K

According to the compositions of the underground gasfield brines in the west of Sichuan Basin, the solu- bilities and densities of the solid-liquid equilibria in the quaternary system Na＋, K＋//Br-, B4O72--H2O at 298 K were determined by the method of isothermal solution saturation. From the experimental data, the phase diagram, water content diagram and density-composition diagram were obtained. This quaternary system is of simple eutectic type, without double salt and solid solution. There are two invariant points, five univariant curves, four fields of crystalli- zation in the system. The equilibrium solid phases are Na2BaO7·10H20, K2B4O7·4H2O, NaBr·2H2O and KBr. Na2B4O7·10H2O has a larger crystallization field, and NaBr·2H2O has a smaller crystallization field. It is also found that bromide has the salting-out effect on borate in the quaternary system Na＋, K＋//Br-, B4O72--H2Oat 298 K.     

Metastable Phase Equilibrium in the Reciprocal Quaternary System LiCl+MgCl2+Li2SO4+MgSO4+H2O at 348.15 K and 0.1 MPa

The metastable solubilities and the physicochemical properties including density and pH of the reciprocal quaternary system(LiCl+MgCl₂+Li₂SO₄+MgSO₄+H₂O) at 348.15 K and 0.1 MPa were determined using the isothermal evaporation method. The dry-salt diagram and water-phase diagram were plotted based on the experimental data. There are five invariant points, eleven univariant curves, and seven crystallization zones corresponding to hexahydrite, tetrahydrite, kieserite, bischofite, lithium sulfate monohydrate, lithium chloride monohydrate and lithium carnallite. Comparison between the stable and metastable diagrams at 348.15 K indicates that the metastable phenomenon of magnesium sulfate is obvious, and the crystallization regions of hexahydrite and tetrahydrite disappear in the stable phase diagram. A comparison of the metastable dry-salt phase diagrams at 308.15, 323.15 and 348.15 K shows that with the increasing of temperature the epsomite crystallization zone disappears from the dry-salt phase diagram of 303.15 K, and a new kieserite crystallization zone is presented at 348.15 K. The density and pH in the metastable equilibrium solution present regular change with the increasing of Jänecke index J(2Li⁺), and the calculated densities using the empirical equation agree well with the experimental values.     

Equilibrium Phase Behavior of Ethylene Glycol/Glycerin＋RbNO3/CsNO3＋H2O at 288.15 and 298.15 K

The solubilities, densities and refractive indices for the four ternary systems ethylene glycol/glycerin＋ RbNOJCsNO3＋H20 were measured with mass fractions of ethylene glycol or glycerin in a range of 0 to 1.0 at 288.15 and 298.15 K. In all the cases, the presence of either ethylene glycol or glycerin significantly reduces the solubilities of the rubidium nitrate and cesium nitrate in aqueous solution, but the refractive indices increase with the increase of mass fraction of either ethylene glycol or glycerin. The density, refractive index and solubility of the saturated ternary systems were correlated with each other via polynomial equations. In addition, the refractive indices and densities of unsaturated solutions were also determined for the four ternary systems with different salt concentrations, which were correlated with the salt concentration and proportion of ethylene glycol or glycerin in the solution.     

Measurement of Solid-liquid Equilibria in Quaternary System Li+, K+//SO42-, B4O72--H2O at 288 K

In order to utilize the brine resources in China, the solid-liquid equilibria in quaternary system Li⁺, K⁺//SO₄^2-, B₄O₇^2--H₂O at 288 K was studied by the isothermal solution equilibrium method. Solubilities and densities of solutions were determined experimentally. According to the experimental data, the equilibrium phase diagrams, density-composition diagram and corresponding water content diagram of the quaternary system were plotted. Double salt KLiSO₄ was found in the reciprocal quaternary system Li⁺, K⁺//SO₄^2-, B₄O₇^2--H₂O at 288 K. The quaternary system has three invariant points, seven univariant curves and five fields of crystallization. The five crystallization regions correspond to Li₂B₄O₇·3H₂O, Li₂SO₄·H₂O, K₂B₄O₇·4H₂O, K₂SO₄ and KLiSO₄, respectively. The crystallization field of salt Li₂B₄O₇·3H₂O is the largest, whereas that of Li₂SO₄·H₂O is the smallest. The experimental results show that Li₂SO₄·H₂O has a strong salting-out effect on other salts.     

Phase Equilibria of Quaternary System NaCl-NaBr-Na2B4O7-H2O at 348 K

The phase equilibria of quaternary system NaCl-NaBr-Na₂B₄O₇-H₂O at 348 K were studied by the isothermal equilibrium method. The solubilities and densities of the equilibrium solution were determined. According to the experimental data, the phase diagram, density-composition diagrams and water content diagram of the quaternary system at 348 K were plotted respectively. And the phase diagram consists of one univariant curve, two crystallization fields and without any invariant point of the quaternary system. The equilibrium solid phases of the two crysta- llization fields were Na(Cl, Br) and Na₂B₄O₇·5H₂O. The experimental results show that the quaternary system contained solid solution. The densities of the solution decrease with increasing NaCl concentration and increase with increasing NaBr concentration.     

Measured and Predicted Solubility Phase Diagrams of Quaternary Systems LiBr-NaBr-MgBr2-H2O and LiBr-KBr-MgBr2-H2O at 298.15 K

The stable phase equilibria of quaternary systems LiBr-NaBr-MgBr₂-H₂O and LiBr-KBr-MgBr₂-H₂O at 298.15 K were studied by both experimental measurement(isothermal solution saturation method) and theoretical prediction(Pitzer model). The solubilities of the saturated solution have been determined experimentally and two stable phase diagrams and relevant water diagrams of the two quaternary systems were obtained. Results show that quaternary system LiBr-NaBr-MgBr₂-H₂O is hydrate II type as NaBr and NaBr·2H₂O coexistence. Its phase diagram consists of only one invariant point, four univariant curves, and five crystallization fields. The quaternary system LiBr-KBr-MgBr₂-H₂O is a complex type as the double salt KBr·MgBr₂·6H₂O formed. In addition to this double salt, the three single salts LiBr·2H₂O, KBr and MgBr₂·6H₂O also crystallize. In this paper, the solubilities of phase equilibria in above quaternary systems were also calculated by the Pitzer's electrolyte solution model. All the needed parameters can be obtained from the literature or be fitted by experimental data. On the Basis of the experimental and calculated results, the phase diagram of the quaternary system was plotted for comparison. It shows that the calculation results are consistent with the experimental ones.     

Synthesis,Structure and Characterization of Three Metal Molybdate Hydrates: Fe(H2O)2(MoO4)2·H3O,NaCo2(MoO4)2(H3O2)and Mn2(MoO4)3·2H3O

Three metal molybdate hydrates,Fe(H2O)2(MoO4)2·H3O(FeMo),NaCo2(MoO4)2(H3O2)(CoMo)and Mn2(MoO4)3·2H3O(MnMo),were synthesized by the mixed-solvent-thermal methods and characterized by singlecrystal X-ray...     

Synthesis,Structure Characteristic and Thermal Behavior of Two New Metal-organic Azo-triazole Compounds: [Zn(phen)3]·ZTO·6H2O and[Cu(phen)3]·ZTO·6H2O

[Zn(phen)₃]·ZTO·6H₂O(1) and[Cu(phen)₃]·ZTO·6H₂O(2) were synthesized by the reaction of Zn(NO₃)₂·6H₂O/Cu(NO₃)₂·3H₂O with 4,4-azo-1H-1,2,4-triazol-5-one(ZTO) and 1,10-phenanthroline(phen). The two compounds were characterized by elemental analysis and IR spectrum analysis, respectively. Compound 1 was also characterized by single crystal X-ray diffraction analysis. For compound 1, the coordination geometry around the Zn²⁺ is a distorted octahedron, with the bite angles of 76.7(3)°-77.6(4)° for all three phen ligands. Moreover, the thermal behaviors and thermal decomposition kinetics were studied and analyzed. Besides, thermal stability and safety parameters(T_SADT, T_b) are 164.7 and 166.4℃ for compound 1, and 149.6 and 150.8℃ for compound 2, respectively.     

三元体系LiCl-CS(NH2)2-H2O及LiCl-CH3CONHCONH2-H2O的研究

关于钾盐-有机物-水体系的研究至今报导甚少,B·Begaliev^[1]等对体系LiCl·CO(NH₂)₂-H₂O进行了研究,发现有两个复合物:LiCl·CO(NH₂)₂,LiCl·3CO(NH₃)₂生成.为了进一步探讨这类体系中锂盐与有机物的相互作用,本文对LiCl·CS(NH₂)₂-H₂O(Ⅰ)(0°,25℃)和LiCl-CH₃CONHCONH₂-H₂O(Ⅱ)(0°,35℃)两个体系进行了研究.     

CuSO4(ZnSO4)-CO(NH2)2-H2O三元体系在30℃时的等温溶度研究

报道了CuSO₄(ZnSO₄)-CO(NH₂)₂-H₂O两个三元体系在30℃时的等温溶度及饱和溶液的折光率,绘制了相应的溶度图和折光率-组成图.两个三元体系中分别形成了组成为CuSO₄·3CO(NH₂)₂·H₂O(异成分溶解)和ZnSO₄·CO(NH₂)·2H₂O(同成分溶解)的化合物,并通过元素分析、红外光谱、X射线粉末衍射及热分析对新相进行了表征.     

新的四帽Keggin结构的金属-氧簇合物[NiMo12O40H10{Ni(H2O)3}4]的水热合成与结构表征

多金属氧酸盐 (也称金属 -氧簇 )由于在催化、材料及医药等领域的应用日益广泛而备受关注 .近年来 ,一些新颖的非经典结构的化合物不断被合成出来 .如带二帽的 Keggin结构化合物 [V15O4 2 ]9- [1] ,[PV14 O4 2 ]9- [2 ] ,[As V14 O4 2 ]9- [3 ] ,[{ Mo8V7O4 2 } 2 ]14 - [4 ] ,     

LaCl3-CH3CONH2-H2O体系的研究

本文报告三元体系LaCl₃-CH₃CONH₂-H₂O 在0℃和30℃的溶度及其饱和溶液的折光指数值。在这两个温度下都没有发现等人^[2]在1976年所报导的LaCl₃·6H₂O的存在。     

The electrolyte NRTL model and speciation approach as applied to multicomponent aqueous solutions of H2SO4, Fe2(SO4)3, MgSO4 and Al2(SO4)3 at 230–270 °C

This work presents chemical modeling of solubilities of metal sulfates in aqueous solutions of sulfuric acid at high temperatures. Calculations were compared with experimental solubility measurements of hematite (Fe₂O₃) in aqueous ternary and quaternary systems of H₂SO₄, MgSO₄ and Al₂(SO₄)₃ at high temperatures. A hybrid model of ion-association and electrolyte non-random two liquid (ENRTL) theory was employed to fit solubility data in three ternary systems H₂SO₄–MgSO₄–H₂O, H₂SO₄–Al₂(SO₄)₃–H₂O at 235–270 °C and H₂SO₄–Fe₂(SO₄)₃–H₂O at 150–270 °C. Employing the Aspen Plus™ property program, the electrolyte NRTL local composition model was used for calculating activity coefficients of the ions Al³⁺, Mg²⁺ Fe³⁺ and SO₄²⁻, HSO₄⁻, OH⁻, H₃O⁺, respectively, as well as molecular species. The solid phases were hydronium alunite (H₃O)Al₃(SO₄)₂(OH)₆, hematite Fe₂O₃ and magnesium sulfate monohydrate (MgSO₄)·H₂O which were employed as constraint precipitation solids in calculating the metal sulfate solubilities. A correlation for the equilibrium constants of the association reactions of complex species versus temperature was implemented. Based on the maximum-likelihood principle, the binary interaction energy parameters for the ionic species as well as the coefficients for equilibrium constants of the reactions were obtained simultaneously using the solubility data of the ternary systems. Following that, the solubilities of metal sulfates in the quaternary systems H₂SO₄–Fe₂(SO₄)₃–MgSO₄–H₂O, H₂SO₄–Fe₂(SO₄)₃–Al₂(SO₄)₃–H₂O at 250 °C and H₂SO₄–Al₂(SO₄)₃–MgSO₄–H₂O at 230–270 °C were predicted. The calculated results were in excellent agreement with the experimental data.     

在288.15K时H3BO3-MgCl2-MgSO4-H2O四元体系的溶解度等温线

研究了MgCl₂-MgSO₄-H₂O、H₃BO₃-MgCl₂-H₂O、H₃BO₃-MgSO₄-H₂O三个三元体系及由它们所组成的四元体系H₃BO₃-MgCl₂-MgSO₄-H₂O在288.15K的溶解度等温线。确定了六水硫酸镁的存在,讨论了各相之间的关系及各化合物相互间的盐析作用。