Fe^(2+)-Ni^(2+)-NH_3-NH_4^+-C_2O_4~2-H_2O体系的沉淀配合平衡热力学  

Thermodynamics of precipitation-coordination equilibrium in Fe^(2+)-Ni^(2+)-NH_3-NH_4^+-C_2O_4~2-H_2O system

作　　者：张传福[1] 姚永林[1] 湛菁[1] 

机构地区：[1]中南大学冶金科学与工程学院,长沙410083

出　　处：《中国有色金属学报》2012年第10期2938-2943,共6页The Chinese Journal of Nonferrous Metals

基　　金：高等学校博士学科点专项科研基金资助项目(20090162120080);湖南省科学技术厅科技计划一般项目(2010FJ3012)

摘　　要：针对草酸盐配位共沉淀热分解还原法制备超细铁镍合金粉过程中Fe2+-Ni2+-NH3-NH4+-C2O42--H2O体系的溶液平衡建立热力学分析模型,并根据模型进行相关计算,揭示反应体系中各物质随pH值、氨及草酸浓度的变化关系。结果表明:溶液中的Fe主要以[Fe(C2O4)n]2 2n络合物形式存在,而铁氨络合物含量很低。当氨含量较低时,溶液中的Ni主要以[Ni(C2O4)n]2 2n存在;氨含量较高时,在酸性条件下,溶液中的Ni主要以[Ni(C2O4)n]2 2n存在,在碱性条件下,则主要以[Ni(NH3)n]2+存在。低pH值下,Ni的沉淀率较Fe的高,而高pH值下,Ni的沉淀率则较Fe的低。The thermodynamics model of the precipitation-coordination equilibrium in Fe2＋-Ni2＋-NH3-NH4＋-C2O42-H2O system was established and the calculation of the model was carried out. The relationships of each substance in solution with pH value, ammonia and oxide acid were revealed. The results show that, Fe in solution exists as [Fe（C2O4）n]2-2n mainly in contrast to low content of [Fe（NH3）n]2＋. At low ammonia content, Ni in solution exist as [Ni（C2O4）n]2-2n mainly. At high ammonia contents, Ni in solution exists as [Ni（C2O4）n]2-2n and [Ni（NH3）n]2＋ under acidic and alkaline conditions, respectively. The precipitation rate of Ni is higher than that of Fe at low pH value, and lower than that of Fe at high pH value.

关 键 词：铁镍合金 溶液平衡 络合 氨 草酸 PH值 

分 类 号：TQ138.1[化学工程—无机化工]