【摘要】 针对反应体系Cu²⁺-Ni²⁺-NH₃-NH₄⁺-C₂O₄^2--H₂O中Cu²⁺和Ni²⁺的反应行为,根据物质守恒原理,建立热力学数学模型。模拟计算结果表明,该体系中金属离子的沉淀是一个复杂的动态平衡过程;在高pH条件下,Cu²⁺和Ni²⁺与NH₃配合分别形成[Cu（NH₃）_n]²⁺（n=3-5）和[Ni（NH₃）_m]²⁺（m=3-6）的反应占主导地位。当[C₂O₄^2-]T=0.6 mol/L时,Cu²⁺和Ni²⁺的共沉淀pH范围在[NH₃]_T为0.6 mol/L和4.2 mol/L时分别为2.0-6.5和2.0-5.5。在pH>7.0的纯水体系中,由于Cu²⁺和Ni²⁺的分步沉淀,Cu-Ni草酸复盐热分解后得到的产物为Cu-Ni复合物。改变沉淀介质为混合溶剂（水/乙醇）可最终制备具有高纯度和良好结晶度的棒状Cu-Ni合金粉末。更多还原

【Abstract】 To investigate the behaviors of Cu²⁺and Ni²⁺with the change of conditions in Cu²⁺-Ni²⁺-NH₃-NH₄⁺-C₂O₄^2--H₂O reaction system,mathematical models of thermodynamics based on the principle of mass conservation were established.The simulation results indicate that the precipitation of metal ions from the aqueous phase is a complicated dynamic equilibrium process,during which the coordination reactions of Cu²⁺ and Ni²⁺ with NH₃ forming[Cu（NH₃）_n]²⁺（n=3-5） and [Ni（NH₃）_m]²⁺（m=3-6） are predominant under high pH conditions,respectively.The pH ranges for the simultaneous precipitation of Cu²⁺ and Ni²⁺ are 2.0-6.5 and 2.0-5.5 when [NH₃]_T equals 0.6 and4.2 mol/L,respectively,with the prefixed [C₂O₄^2-]_T of 0.6 mol/L.Due to the fractional precipitation of Cu²⁺ and Ni²⁺,Cu-Ni composite is obtained after the thermal decomposition of Cu-Ni oxalate complex salts prepared in a pure water system when pH>7.0.By applying the mixed solvent（water/ethanol） as the precipitation medium,the Cu-Ni alloy rods can be finally fabricated with high purity and crystallinity.更多还原