Translated Title
Thermodynamic equilibrium in Co-Ni-Fe-Mn complexation?precipitation system
Translated 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.
Translated Keyword
secondary resources of cobalt and nickel
complexation?precipitation system
thermodynamics
Access Number
WF:perioarticalzgysjsxb201302033
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