Ni(Ⅱ)-NH_3-NH_4Cl-H_2O体系中物种研究

Study of species in Ni(Ⅱ)-NH_3-NH_4Cl-H_2O system

根据同时平衡原理,借助计算机牛顿迭代,计算了在Ni( )-NH3-NH4Cl-H2O体系中各物种平衡浓度。通过绘制组份分布图,探讨了Ni(NH3)2+i(i=1,2,…,6)、Ni(OH)2-nn(n=1,2,…,4)、NiCl+络合物平衡浓度随NiCl2、NH4Cl、NH3·H2O及pH值的变化规律;组份分布图中提供了参于电荷转移步骤的NiOH+离子平衡浓度的变化规律,为电结晶过程的机理研究奠定基础;pH值<9.5的范围内,随pH值升高,反应物种平衡浓度均降低,因此pH值不应太高,与实验确定的最佳工艺相吻合。

According to the principles of simultaneous equilibrium, the equilibrium concentration of each species in the Ni (Ⅱ)\|NH\-3\|NH\-4Cl\|H\-2O system is calculated with computation methods. The influences of NiCl\-2, NH\-4Cl, NH3·H\-2O concentration and pH value on the equilibrium concentration of Ni(NH\-3)\+\{2+\}\-i(\%i\%=1,2,…,6)、Ni(OH)\+\{2-\%n\}\-n\%(\%n\%=1,2, …,4)、NiCl\++ are discussed. The changing of NiOH\++ concentration is showed in the diagram of each species, equilibrium distribution, which is useful in the study of the electro\|crystallization mechanism for its important role in the electron\|exchange step. Under the condition pH<9.5, the equilibrium concentration of the species that take part in the electro\|chemical reaction will decrease with the increasing of the pH value, so the pH value must not be high, which is approved by laboratory experiments.