摘要
According to the principles of simultaneous equilibrium and mass balance, a series of thermodynamic equilibrium equations of Ni（Ⅱ）-C2O2-4-NH3-NH+4-H2O system at ambient temperature are deduced theoretically and the logarithm concentration versus pH value（lg[Ni2+]T—pH） diagrams at different solution compositions are drawn. The results show that when pH is above 8.0, nickel ions coordinate with ammonia, the precipitation proceeds slowly accompanying with the release of nickel ions from the multi-coordinated Ni（NH3）2+n（n=1, 2, …, 6） and the morphology of NiO powder precursor is fibrous; when pH is below 8.0, nickel ion directly reacts with C2O2-4 and the morphology of NiO powder precursor is of cubic-shape. Some experiments were made to confirm the relation between the total concentration of nickel ion and pH. It is shown that the thermodynamic mathematical model is correct and the calculated values are basically accurate.
According to the principles of simultaneous equilibrium and mass balance, a series of thermodynamic equilibrium equations of Ni（ Ⅱ）-C2 O4^2--NH3-NH4^＋-H2O system at ambient temperature are deduced theoretically and the logarithm concentration versus pH value（lg[Ni^2＋ ]r-pH） diagrams at different solution compositions are drawn. The results show that when pH is above 8.0, nickel ions coordinate with ammonia, the precipitation proceeds slowly accompanying with the release of nickel ions from the multi-coordinated Ni（NH3）n^2＋ （n= 1, 2,…, 6） and the morphology of NiO powder precursor is fibrous; when pH is below 8.0, nickel ion directly reacts with C2O4^2- and the morphology of NiO powder precursor is of cubic-shape. Some experiments were made to confirm the relation between the total concentration of nickel ion and pH. It is shown that the thermodynamic mathematical model is correct and the calculated values are basically accurate.
出处
《中国有色金属学会会刊：英文版》
EI
CSCD
2005年第4期926-930,共5页
Transactions of Nonferrous Metals Society of China
基金
Project(1998053306) supported by the Doctoral Foundation of Education Ministry of China
关键词
NIO
草酸盐
纤维
热力学分析
盐类体系
thermodynamic analysis
NiO precursor powder
fibrous shape
cubic-shape
