How to separate impurities nickel, from acidic solutions containing cobalt and / or scandium

Provided manganese, iron, zinc, nickel from acidic solutions containing impurities such as aluminum, a method capable of separating efficiently and cobalt and / or scandium and impurities. A valuable metal extractant of the present invention is represented by the following formula. In the formula, R The following general formula, glycine units, histidine units, lysine units, aspartic acid unit or n - have a methyl glycine units preferable. .Field