文摘
Separation of Ni2+ from ammonia/ammonium chloride solution using a flat-sheet supported liquid membrane (SLM) impregnated with Acorga M5640 in kerosene was investigated. The fundamental experimental variables influencing Ni2+ transport, such as ammonia concentration, carrier concentration, H2SO4 concentration in the stripping solution, stirring speed, and initial Ni2+ concentration were studied. Almost all of Ni2+ was transported from the feed to the stripping phase after 18 h of operation with a permeability coefficient of 9.28 × 10−6 m s−1 under optimum conditions: stirring speed of 1000 rpm in both phases, 20 vol.% Acorga M5640 as the carrier, 1.70 mmol L−1 Ni2+ in the feed phase and 0.10 mol L−1 H2SO4 in the stripping phase. The flux value of Ni2+ was 15.82 × 10−6 mol m−2 s−1. Additionally, the influences of temperature and ultrasound on flux were examined, and results indicated that higher temperature and ultrasonic assistance improved transport of Ni2+ through the SLM. Selective separation of nickel from cobalt in an ammonia/ammonium chloride solution was also achieved through SLM. The stability of the SLM was examined on a continuous run mode and satisfactory stability of the nickel permeation was observed for 84 h (7 runs).
