Selective Extraction and Separation of Trace Amounts of Cobalt-57 from Nickel

Trace amounts of cobalt-57 were separated from nickel and extracted into isopherone in the presence of thiocyanate as a complexing agent. The effect of various parameters on the separation yield was investigated. These include: concentration of the complexing agent, aqua and organic phases volume ratio and acidity of aqua phase. The extracted cobalt-57 was backextracted into concentrated hydrochloric acid and the effects of hydrochloric acid concentration and volume on backextraction yield were investigated. 4% (WN) ammonium thiocyanate solution, pH=1.5-2 and lower organic to aqua volume ratio gives the highest separation yield. 99.57% back extraction yield was achieved for cobalt-57 through 5 steps of washing with 5N HCI.