CaSO4-Ca（OH）2-H2O体系相平衡（英文）

为了给含高浓度硫酸根离子的重金属废水中和法处理提供理论指导,并更好地理解硫酸钙结垢的形成机制,采用Pitzer电解质溶液理论计算298.15K时CaSO4-Ca（OH）2-H2O三元体系的溶解度,并采用光学法结合XRD测试技术测定该体系的等温平衡溶解度,采用计算和实验方法分别绘制相图。研究了5个区域的物理定义及特征点、线所表达的物理规律,并分析了各区域SO42-浓度对中和水解过程pH调节的影响。中和水解过程pH值的调节取决于体系中SO24-离子的浓度。Ca（OH）2与CaSO4·2H2O在水中溶解时,相互影响的规律体现在相图中的点、线及面上。     

CaCl2-Ca（OH）2-H2O体系中氢氧化钙的平衡浓度

绘制了25℃时CaCl2-Ca(OH)2-H2O体系的c(CaCl2)—c(Ca(OH)2)图和c(CaCl2)—pH值图。结果表明:体系中c(Ca(OH)2)和pH值随着c(CaCl2)的增加而不断减小,c(Ca(OH)2)变化趋势与Debye-Huckel计算值相符,当c(CaCl2)<3.78 mol/L时,体系pH值>10.4。当c(CaCl2)>2.57mol/L时,有沉淀物CaClOH生成。经计算,理论上CaCl2母液可以循环配制石灰水132次,研究结果为石灰水法制备氢氧化镁工艺中CaCl2母液循环配制石灰水提供了一定的理论依据。     

Thermodynamics and technology of extracting gold from low-grade gold ore in system of NH4Cl-NH3-H2O

1 Introduction Hydrometallurgy with ammoniacal ammonium chloride as extracting system is a new developing field with many merits. Above all, NH3 and Cl- ions existing in the system have relatively high complex ability with some heavy or noble metal ions. …     

Synthesis and high-temperature performance of Ti substituted α-Ni（OH）2

1 INTRODUCTION The development of electric and hybrid vehi- cles is proceeding against the backdrop of environ- mental problems ,and nickel-metal hydride batter- ies( MH/Ni) with high output ,high energy densi- ty ,low cost and long durability are being consid- ered the alternative cardinal components for these vehicles .In recent years , synthesis of Ni(OH)2 powder with perfect high-temperature electrochem- ical properties has gotten more and more attention since the lowcharge acceptanc…     

Al代α-Ni（OH）2充电效率的研究

利用LAND充放电测试仪考察了1种新型的镍氢电池正极材料α-Ni(OH)2充电过程中析出O2量的变化，对α—Ni(OH)2的充电效率进行了研究。结果表明Al代α-Ni(OH)2的充电效率高于β-Ni(OH)2。随着合成温度的升高，α—Ni(OH)2的充电效率增加到一定值后趋于稳定。环境温度升高，充电效率增加。电流密度增加，充电效率几乎没有变化，说明α-Ni(OH)2电极的大电流性能很好。     

Al代α-Ni（OH）2的结构与电化学性能

采用化学共沉积法制备了Al代α-Ni(OH)2并对其结构和电化学性能进行了研究。采用XRD，IR，SEM和TGA等方法研究了其结构特征和热稳定性，采用循环伏安法研究了所制备的α-Ni(OH)2的电化学性能。结果表明：采用25mol％的Al取代的方法得到的晶体结构为α-Ni(OH)2，且试样可以在碱性溶液中稳定存在。与β-Ni(OH)2相比，其具有较大的扩散系数，电极反应受扩散控制。     

Preparation of homogeneous ZnO nanoparticles via precipitation-pyrolysis with Zn5（CO3）2（OH）6 as precursor

1 Introduction Recently, demands for high product performance products have necessitated a precise control of ZnO particle properties for applications such as electrode of solar cells and photocatalysts. Much attention is given to the high chemical reacti…     

Initial atmospheric corrosion of zinc in presence of Na2SO4 and （NH4）2S04

Initial atmospheric corrosion of zinc in the presence of Na₂SO₄ and (NH₄)₂SO₄ was investigated via quartz crystal microbalance(QCM) in laboratory at relative humidity(RH) of 80% and 25 °C. The results show that both Na₂SO₄ and (NH₄)₂SO₄ can accelerate the initial atmospheric corrosion of zinc. The combined effect of Na₂SO₄ and (NH₄)₂SO₄ on the corrosion of zinc is greater than that caused by (NH₄)₂SO₄ and less than that caused by Na₂SO₄. Fourier transform infrared spectroscopy(FTIR), X-ray diffractometry(XRD) and scanning electron microscopy(SEM) were used to characterize the corrosion products of zinc. (NH₄)₂Zn(SO₄)₂, Zn₄SO₄(OH)₆·5H₂O and ZnO present on zinc surface in the presence of (NH₄)₂SO₄ while Zn₄SO₄(OH)₆·5H₂O and ZnO are the dominant corrosion products on Na₂SO₄-treated zinc surface. Probable mechanisms are presented to explain the experimental results.     

钴的添加方式对α-Ni（OH）2电化学性能的影响

采用化学共沉淀法制备了可以在强碱性溶液中稳定存在的α—Ni（OH）2，比较了物理添加Co粉、晶格掺杂Co^2＋以及表面包覆Co（OH）2等Co的不同添加方式对α-Ni（OH）2电化学性能的影响。利用X射线衍射（XRD）对电极循环过程中的结构变化进行了表征，采用恒流充放电测试方法研究了所制备的α-Ni（OH）2在不同电流密度下的放电比容量。结果表明3种方式添加Co都可以在一定程度上提高样品的循环稳定性和大电流放电比容量，其中以表面包覆Co（OH）2的方式效果最为明显。     

Equilibrium of hydroxyl complex ions in Pb^2＋-H2O system

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.     

Bi^3＋—Cl^——H2O系热力学平衡

运用同时平衡原理和质量平衡原理对Ｂｉ＾３－Ｃｌ－Ｈ２Ｏ体系进行热力学分析和计算，在此基础上绘制了Ｂｉ＾３＋－Ｃｌ－Ｈ２Ｏ体系在２５℃下的各种涫淀物的平衡浓度对数－ＰＨ图，分析确定了各大相沉淀物稳定存在的ＰＨ。结果表明，溶液中铋离子和硝酸根离子的浓度及溶液的ＰＨ值是影响各固相稳定存在的重要参数。由热力学图得出，可以直接从溶液中沉淀的Ｂｉ２Ｏ３，要得到高纯工的ＢｉＯＣｌ必须严格控制溶液的ＰＨ范围。     

Thermodynamic calculation of Sn(IV)-NH~(4 )-Cl~--H_2O system

1　INTRODUCTIONAntimonydopedtinoxide ,forshortATO ,withexcellentconductivityperformance ,isakindofmetaloxide powders .Duetoitswideapplication ,thepreparationandapplicationareabroadintheworld .Atpresent ,tincompoundssuchasSnCl4 ·5H2 O ,SnO2 andSn(OH) 4areusuallyusedtoprepareATOpowders[18] .Allthesestanniccompoundsarepre paredbypure ,expensivetin ;furthermore ,SnCl4 isveryeasytovolatilize ,whichcauseshardmeasure ment ;inaddition ,usingSnO2 orSnO2 ·2H2 Otopre pareATOdemandforrigo…     

Thermodynamic calculation of Sn (Ⅳ)-NH4+-Cl--H2O system

According to the principles of simultaneous equilibrium and electronic charge neutrality, the thermodynamics of Sn(Ⅳ)-NH4 -Cl- -H2O system under normal condition was calculated. Relation between all sorts of complex of Sn4 and pH was plotted. Based on thermodynamics analysis and calculation, some experiments were done to validate the relation between the total concentration of tin ion and pH in this system. The results suggest that the total concentration of ammonium and pH are the most important factors which determine whether (NH4)2SnCl6 or Sn(OH)4 exists in this system. Results further suggest when contnet of HCl is more than 6 mol/L, Sn4 in this system will be also precipitated in the form of (NH4)2SnCl6. These results lay the solid theory foundation to preindium tin oxide(ITO), from the tinny material.     

硅锌矿在(NH_4)_2SO_4-NH_3-H_2O体系中的浸出机理

对硅锌矿在(NH4)2SO4-NH3-H2O体系中的浸出行为进行了系统研究,揭示浸出反应机理,阐明其难以浸出的内在原因。结果表明:硅锌矿浸出反应方程为Zn2SiO4(s)+(2i-4)NH3(aq)+4NH4+=2[Zn(NH3)i]2++SiO2(s)+2H2O(l),i=1～4。浸出中,硅锌矿中的硅溶解进入溶液,再以无定形SiO2形态从溶液中析出。SiO2在(NH4)2SO4-NH3-H2O体系中的溶解度很低,仅略高于0.3 g/L,而其从溶液中的析出速度非常缓慢,是硅锌矿在该体系中难以浸出的主要原因。当液固质量比从5提高至500时,锌浸出率将从2.72%提高至84.15%。     

V(Ⅴ)-Fe(Ⅲ)-S(Ⅵ)-H2O系热力学研究与钒铁分离方法理论

针对酸浸液钒铁分离的难题,绘制298 K时V(Ⅴ)-Fe(Ⅲ)-S(Ⅵ)-H2O系中存在的各种离子随pH以及浓度变化的热力学平衡图,全面分析钒、铁物种随pH和钒、铁、硫浓度的变化规律,在此基础上提出相应的钒铁分离方法并进行理论分析。结果表明:强酸条件(?1相似文献   

基于同时平衡原理的Au-I~--H_2O系热力学分析

采用同时平衡原理对Au-I--H2O系的浸金热力学进行分析,分别研究溶液与固体Au以及Au I沉淀与固体Au平衡时的φ-p H关系、Au I存在条件和溶液中含金组分的变化规律。结果表明:随着溶液中含金组分的总浓度cT(Au)的降低或含碘组分的总浓度cT(I-)的增加,还原电位φsol/Au迅速降低,Au3+/Au2O3的平衡p H值增大,非常有利于金的碘化浸出;随着溶液中cT(I-)逐渐增加,出现Au I沉淀且其沉淀量呈先增大后减小的趋势;在cT(Au)为1×10-4 mol/L的条件下,当溶液中cT(I-)浓度大于0.0021 mol/L时,可避免Au I沉淀的生成,金主要以Au I2-络合离子形式存在。Au-I--H2O系的浸金热力学分析为金的高效碘化浸出提供了理论依据。     

Li-Fe-P-H2O系热力学分析

运用同系线性规律对Li-Fe-P-H2O系中缺少的LiFePO4和Li3PO4的ΔG■进行估算。结合已有的热力学数据,运用φ—pH图的绘制原理,得到25℃时Li-Fe-P-H2O系在不同浓度下的φ—pH图。结果表明,在水溶液中,LiFePO4具有较大的热力学稳定区域,这对湿法制备LiFePO4很有利。根据所绘制的热力学平衡图,详细讨论了各种LiFePO4软化学制备方法的可行性途径,并就液相法制备LiFePO4可能的技术途径和条件进行分析,为在水溶液中用软化学法制备LiFePO4提供理论依据。     

Li-Mn-H2O系热力学分析

绘制了25.℃时Mn-H2O与Li-Mn-H2O系的ε-pH图, 并对锂离子电池用正极材料锰酸锂的湿化学制备以及溶液中锂的回收问题从热力学上进行了分析, 指出了可能的技术途径和对策; 计算发现, LiMn2O4完全或部分地占据了各种价态锰离子化合物的稳定区域, 在水溶液中的稳定性很好. 这对湿法制备LiMn2O4十分有利; 而LiMnO2的稳定性较差, 仅在溶液中维持较高锂离子浓度时才可存在. 湿法制备LiMnO2的条件较为苛刻; 对于从溶液中回收锂, 锰的固体氧化物如MnO2无疑是极佳的吸附剂, 理论上有很高的回收率. 吸附的锂宜采用提高溶液电势的方法进行氧化性解吸.