(北京工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，北京 100124)
摘 要: 根據(jù)質(zhì)量守恒和同時(shí)平衡原理，以Me(Co、Ni、Fe、Mn)為金屬元素，建立Me-OH-、Me-OH--CO32-、Me-OH--S2-、Me-OH--NH3和Me-OH--NH3-CO32-等多個(gè)配合-沉淀體系的熱力學(xué)平衡模型。結(jié)果表明：Fe3+可以在Me-OH-、Me-OH--NH3體系中通過調(diào)節(jié)pH=3預(yù)先沉淀分離，而Co、Ni、Mn僅在Me-OH--NH3-CO32-體系中有分離效果。Me-OH--NH3-CO32-體系熱力學(xué)計(jì)算表明：Co、Ni、Mn在溶液中的行為受pH值、配合劑、沉淀劑濃度共同影響，碳酸根初始總濃度[C]增大和氨初始總濃度[N]減小有利于Co、Ni、Mn形成沉淀。當(dāng)[C]=1 mol/L、 [N]=2 mol/L、pH值為9~10時(shí)，大部分Ni以高級氨配離子[Ni(NH3)42+]、[Ni(NH3)52+]、[Ni(NH3)62+]的形式保留在溶液中，而Co、Mn以MnCO3、CoCO3的形式沉淀出來。Co可在Me-OH--S2-體系中通過調(diào)節(jié)pH<6從溶液中與Mn分離。研究結(jié)果可為鈷鎳二次資源綜合回收鈷鎳、制備鈷鎳產(chǎn)品提供理論指導(dǎo)。
關(guān)鍵字: 配合-沉淀體系；熱力學(xué)；鈷鎳二次資源
（College of Material Science and Engineering, Beijing University of Technology, Beijing 100124, China）
Abstract:Based on mass balance principle and simultaneous equilibrium principle, the metal element Me (Co, Ni, Fe, Mn), complexing agent of OH- and NH3, and precipitant of OH-, S2- and CO32- were chosen to form the complexation–precipitation systems of Me-OH-, Me-OH--CO32-, Me-OH--S2-, Me-OH--NH3 and Me-OH--NH3-CO32-. The thermodynamic equilibriums of these systems were studied. The results show that Fe3+ in systems of Me-OH- and Me-OH--NH3 can be separated by precipitation through adjusting the pH value to 3. However, Co, Ni and Mn can be separated only in Me-OH--NH3-CO32- system. The theoretical calculations show that the behavior of Co, Ni and Mn in Me-OH--NH3-CO32- system is affected by pH value, complexing agent concentration and precipitant concentration. The increase of the total concentration of carbonate [C] is in favor of the precipitation of Ni, Co and Mn, but the increase of the total ammonia concentration [N] has the opposite effect. When [C]=1 mol/L, [N]=2 mol/L and pH value of 9-10, most Ni is complexed in the solution in the form of senior ammonia complexes [Ni(NH3)42+] and [Ni(NH3)52+], [Ni(NH3)62+], while Co and Mn precipitate in MnCO3 and CoCO3. Finally, Co can be separated with Mn from the solution in Me-OH--S2- system when pH<6. The results provide a theoretical guidance for cobalt and nickel recovery from secondary resources and the preparation of cobalt and nickel products.
Key words: complexation-precipitation system; thermodynamics; secondary resources of cobalt and nickel
