Separation Properties Of The Typical Amino Chelating Resin Toward Copper, Nickel And Cobalt Ions From Aqueous Media

Copper, nickel and cobalt are not only an important raw material and strategic resources for the development of national economic construction and national defense science and technology but also an important indicator of environmental pollution. Separation and purification of metal ions are of great practical significance considering the scarcity of such resources. In this work, great efforts are devoted to choose and prepare amine chelating resin to investigate the selective adsorption behaviors for Ni (â…¡), Co (â…¡) and Cu (â…¡) in sole and binary aqueous.A polyamine resin S 984 was selective explored to separate nickel for cobalt. The calculated adsorption capacity for nickel and cobalt was 1.129mmol/g and 0.814mmol/g at pH 5. The experimental data could be well fitted by Langmuir isotherm model. Adsorption thermodynamics revealed that sorption processes was endothermic and spontaneous. The kinetic data could be well fitted by Lagergren-second-order equation. The calculated initial rate constants (h) were in the order of Ni (â…¡)> Co (â…¡). Thomas model could be partly used to predict the breakthrough history of Ni (â…¡) and Co (â…¡) in column adsorption. The breakthrough rate constants were in the order of Co (â…¡)>Ni (â…¡). In the In binary component adsorption study, the lower adsorption yield and initial rate constants of nickel and cobalt validated the antagonism between the two metal ions with the possible direct competitive effects on the active sites of solid phase. The results of competition experiment indicated polyamine resin could selectively remove Ni (â…¡) particularly at the high concentration solution of Co (â…¡). Although S 984 adsorbed preferentially cobalt rather than nickel, the cobalt ions adsorbed were displaced by the subsequent adsorption of nickel ions, The fixed bed breakthrough curves for simultaneous adsorption of Ni (â…¡) and Co (â…¡) demonstrated cobalt ions adsorbed were displaced by the subsequent adsorption of nickel ion on S 984. It could be calculated that the total purity of cobalt in the former 100BV,120 BV and 300 BV effluents could approach to 100%,99.999% and 99.99%, respectively. The effluent solution would satisfy the quality criteria for the production of cobalt, the concentration of other heavy metals lower than 0.0001%.To separate copper for nickel, polymer-supported 6-aminonicotinic acid resin was prepared using chloromethylated macroporous styrene-divinylbenzene copolymers. The characterization of ANA chelating resin was carried out using elemental analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and so on. ANA resin contains 5.70% of N, suggesting the content of functional groups 2.04mmol/g. There existed extensively macroporous distribution and different types of N,O in the resin.In single component adsorption study, adsorption isotherms results indicated that the total sorption capacity was 1.022mmol/g for Cu (â…¡),0.446mmol/g for Ni (â…¡) at pH 5. The static equilibrium fitted Langmuir equation very well, the adsorption behavior was monolayer. The new resin exhibited satisfactory kinetic properties towards metal sorption. The calculated initial rate constants (h) were in the order of Cu (â…¡)> Ni (â…¡). The results of competition experiment indicated that the adsorption capacity towards copper increased when the initial concentration molar ratio increased. It could imply that the adsorption of Cu (â…¡) was not inhibited by Ni (â…¡) and the selectivity toward Ni (â…¡) was excellent onto the ANA in high concentration nickel system. The total purity of nickel in the former 222 BV and 248 BV effluents could approach to 100% and 99.999% as demonstrated in the column experiment. The effluents could be recovered and used through simple concentration. The application of high selective separation technology is of great practical significance considering the scarcity of such resources.