Simultaneous separation of copper from nickel in ammoniacal solutions using supported liquid membrane containing synergistic mixture of M5640 and TRPO

Abstract

This paper addresses the simultaneous separation of copper and nickel from ammoniacal/ammonium chloride solutions using supported liquid membrane containing synergistic mixture of Acorga M5640 and trialkyphosphine oxide (TRPO) as carriers. A number of influencing parameters on the Cu(II) transport and separation of Cu(II) from Ni(II) were studied. The results indicate that the mixture of both carriers (TRPO+Acorga M5640) induces antagonistic effects in the SLM system on the transport of Cu(II) and especially the Ni(II). The difference in strength of the antagonistic effect allows the selective separation of copper over nickel from ammoniacal solutions. The metal ions, Cu(II) and Ni(II), were efficiently separated with a factor 16.0 when the following conditions are employed: stirring speed of 1000rpm in both phases, carrier concentration of (10vol.% TRPO+20vol.% Acorga M5640) in a kerosene based diluent, metal concentrations of 100mg/L for each of the copper and nickel dissolved in 2.0mol/L total ammoniacal feed solution, and 50g/L H2SO4 as a stripping solution. Under the optimal conditions, up to 98.4% of the Cu(II) is transported from the feed phase to the stripping phase within a period of 12h with a permeation coefficient of 1.21×10−5m/s. At the same time, less than 6.1% of nickel is transported, suggesting a substantial selectivity in the transport phenomena of both metals. The membrane stability of the SLM system was also evaluated and shown to be satisfactory for at least fourteen runs (7days of continuous operation).