Study on extraction of cobalt(II) by sodium laurate/pentan-1-ol/heptane/NaCl microemulsion system

A microemulsion consisting of sodium laurate, n -pentanol, n -heptane and NaCl solution was investigated for Co(II) extraction. The dilution method and conductivity method were used for the determination of structural parameters of sodium laurate/pentan-1-ol/heptane/NaCl microemulsion system. Co(II) was found to be extracted into the microemulsion phase due to the compound formation of [CoCl] + [R 11 COO] − , which was confirmed by the continuous variation of R 11 COONa concentration. Moreover, the effects of cosurfactant, the contact time, the phase ratios, PH and the NaCl concentration in feed solutions on the cobalt extraction yield were investigated. Under the optimum conditions, the extraction percentage of Co(II) could reach 98.9%.