Solvent extraction separation of cobalt(II) from nickel and other metals with cyanex 272.

Cobalt(II) was quantitatively extracted at pH 8.0 with 5 x 10(-3)M Cyanex 272 [Bis(2,4,4 trimethyl pentyl) phosphoric acid] in chloroform. Cobalt(II) was stripped with 0.5M nitric acid and was determined by atomic absorption spectrometry as well as by spectrophotometry of the complex with nitroso R salt. Cobalt(II) was separated from vanadium, chromium, nickel, manganese, iron and zinc. Mixtures having different ratios of iron, cobalt and nickel were separated by proposed method.