Extraction of Trivalent Rare Earth Ions with an Acidic Tridentate Extractant, 6-<i>N,N</i>-Di-<i>n</i>-Octylcarbamoyl-Pyridine-2-Carboxylic Acid

Extraction properties of trivalent rare earth ions (RE(III)) from acidic chloride solutions with 6-N,N-di-n-octylcarbamoyl-pyridine-2-carboxylic acid (CPCA), which has three functional groups: an amide, a carboxylic and pyridine, were investigated by slope analyses the distribution ratio (D) RE(III) FT-IR measurements. The dependence D on pH CPCA concentration indicated that 1:3 RE(III)−CPCA complex was predominantly formed in organic phase. analysis Dy(III) extracted suggested coordination mode to tridentate. Plots extraction percentage (E%) versus atomic number revealed E% increased La(III) Er(III) then remained almost constant until Lu(III). Y(III) similar Sm(III).