Application of benzo-12-crown-4 to lanthanum separation from rare earth elements of cerium and yttrium subgroups

A possibility of lanthanide (Ln) mixtures separation by means of precipitation using benzo-12-crown-4(Q) is studied. Lanthanum and neodymium nitrate mixture separation in acetonitrile solution was performed by adding Q up to La:Na:Q=1:1:2.5 concetration ratio and by separating the precipitate of the obtained lanthanum complex. La-Nd mixture separation coefficient made up 750-900, and La-Er - about 1.7 times as much. It is shown that using the difference in the rate of formation of precipitates of Ln(NO3)3xQ complexes for Ln, forming precipitates of various structure, it is possible achieve effective Ln mixture separation by means of single precepitation of their nitrate complexes with Q