Extraction of alkali metal, magnesium and calcium ions with cyclopentadienyltris(diethylphosphito-P)cobaltate(−1)

Abstract The extraction of lithium, sodium, potassium, magnesium and calcium ions with the oxygen tripod ligand cyclopentadienyltris (diethylphosphito-P)cobaltate(−1), [(C 5 H 5 )Co{P(O)(OC 2 H 5 ) 2 } 3 ] − has been studied as a function of pH and ligand concentration.Li + could be successfully separated from Na + and K + . The separation of Li + from fCa 2+ and Mg 2+ was achieved by masking Mg 2+ and Ca 2+ with EDTA or by precipitating them with the ligand before Li extraction. The composition and stability constants have been determined for the complexes of Li + , Mg 2+ , and Ca 2+ .