Cobalt(II) membrane-extraction by DP-8R/Exxsol D100 using pseudo-emulsion based hollow fiber strip dispersion (PEHFSD) processing

摘要

The transport of cobalt(II) from acidic sulphate solutions through PEHFSD was investigated using the\udextractant DP-8R in Exxsol D100. The acidic feed solution containing Co(II) was passed through the tube\udside, and pseudo-emulsions of DP-8R/Exxsol D100 and sulphuric acid was passed through the shell side\udin counter-current mode, using a single microporous hydrophobic polypropylene hollow fiber contactor\udfor extraction and stripping. In PEHFSD the aqueous strip (sulphuric acid) solution was dispersed in the\udorganic membrane solution in a reservoir tank with an impeller stirrer to form a strip dispersion. This\udpseudo-emulsion phase is circulated from the tank to the membrane module to provide a constant supply\udof the carrier solution to the membrane micropores. Several hydrodynamic and chemical parameters,\udsuch as variation in feed pH (3–7), cobalt concentration in feed (0.17–1.7 10 3 M), carrier concentration\ud(0.16–1.28 M), etc., were investigated. Mass transfer modelling was performed and the validity of\udthe model was evaluated with experimental data. Moreover, the system was applied in the cobalt\udpurification of synthetic lithium solutions derived from the processing of rechargeable batteries, with\udcobalt/lithium separation factor values around 25.