Extraction of cobalt(Ⅱ) from aqueous solution by N,N'-carbonyl difatty amides

The development of economic and environmentally friendly extractants to recover cobalt metal is required due to the increasing demand for this metal.In this study,solvent extraction of Co（Ⅱ） from aqueous solution using a mixture of N,N＇-carbonyl difatty amides（CDFAs） synthesised from palm oil as the extractant was carried out.The effects of various parameters such as acid,contact time,extractant concentration,metal ion concentration and stripping agent and the separation of Co（Ⅱ） from other metal ions such as Fe（Ⅱ）,Ni（Ⅱ）,Zn（Ⅲ） and Cd（Ⅱ） were investigated.It was found that the extraction of Co（Ⅱ） into the organic phase involved the formation of 1：1 complexes.Co（Ⅱ） was successfully separated from commonly associated metal ions such as Fe（Ⅱ）,Ni（Ⅱ）,Zn（Ⅲ） and Cd（Ⅱ）.Co（Ⅱ） stripping from the loaded organic phase was studied in aqueous solution.These results are useful to recover Co（Ⅱ） from aqueous solution utilising（CDFAs） as an extractant.