Study on extraction of Ni~(2+) by microemulsion system of P_(204)/Span80/kerosene/NaOH

The formula and stability for microemulsion with saponified P204 and Span80 as mixed surfactants have been studied.Through extraction of Ni2+ from feed phase using the microemulsion system of P204/Span80/kerosene/NaOH,different factors effecting on extraction rate of Ni2+,such as the mass ratio of P204,kerosene and Span80,the concentration of NaOH,the ratio of volume between microemulsion and feed phase,the pH value of feed phase and the times of oil phase recycle,et al,were investigated.The experimental results show the extraction rate of Ni2+ was 99.9% when the mass ratio of P204 to kerosene was 1 ∶2.5,the mass ratio of P204 to Span80 was 1 ∶1,the concentration of NaOH was 1.5 mol/L,the ratio of volume between microemulsion and wastewater was 1 ∶5,the pH value of wastewater was 5.5,the extraction time was 10 min.This microemulsion system exhibits several advantages including good stability,simple process,lower cost,high efficiency of extraction.