Mg(Ⅱ)-NH_3-NH_4Cl-H_2O体系中Mg(Ⅱ)配合平衡热力学  

Thermodynamics of Mg(Ⅱ)complex equilibrium in Mg(Ⅱ)-NH_3-NH_4Cl-H_2O system

作　　者：王瑞祥[1,2] 唐谟堂[2] 曾婕[1] 

机构地区：[1]江西理工大学材料与化学工程学院,江西赣州341000 [2]中南大学冶金科学与工程学院,湖南长沙410083

出　　处：《中国有色冶金》2010年第1期69-73,共5页China Nonferrous Metallurgy

基　　金：江西省教育厅科技项目(GJJ08279);国家"973"计划资助项目(2007CB613604);国家自然科学基金资助项目(50674104)

摘　　要：用双平衡法研究了Mg(Ⅱ)-NH_3-NH_4Cl-H_2O体系中Mg(Ⅱ)配合平衡热力学,得出氨水浓度和氯化铵浓度在0～5 mol/L范围内变化时体系中各物种的平衡浓度,绘制了热力学平衡图,揭示了镁在该体系中的溶解规律。该体系存在着镁的高溶解度区域,镁的溶解度随着氯化铵浓度增加而增加,最高可达1.07mol/L;而在纯氨水中,镁离子浓度不随氨水浓度变化,始终接近0;向体系中添加氯化铵并保持其浓度不变,镁离子浓度随着氨水浓度的升高先略有降低而后逐渐升高,呈现一个浅碟型,在氨水浓度为2.5mol/L附近出现最低点。Thermodynamics of Mg（ Ⅱ ） complex equilibria in Mg（Ⅱ）-NH3-NH4Cl-H2O system was studied based on double equilibrium method. When the concentration of ammonia and ammonium chloride is variable in range of 0-5mol/L, the equilibrium concentrations of all species were calculated, respectively, and thermodynamic diagrams were plotted. The dissolution laws of Mg（Ⅱ） in the system are revealed and the high dissolution fields of Mg（ Ⅱ ） are found. The solubility of magnesium increase with the ammonium chloride concentration increasing, and the highest solubility reaches 1.07 mol/L, whereas the concentration of magnesium always remains 0 in pure ammonia solution. Added ammonium chloride to the solution and maintain its concentration constant, the concentration of magnesium decreases slightly with ammonia concentration increasing at first subsequently it increases and presenting a fiat dish figure. The bottom appears at the concentration of ammonia 2.5 mol/L.

关 键 词：NH3-NH4Cl-H2O体系 热力学 Mg(Ⅱ)配合平衡 双平衡法 

分 类 号：O642.42[理学—物理化学]