Distribution of trace amounts of M2+ ions during Co(CH3COO)2·4H2O crystallization

摘要

Distribution coefficients(Henderson-Kracek,Khlopin),D_(2/1),of trace amounts of Ni2+,Mg2+,Cu2+,Zn2+,Mn2+,Cd2+,Ca2+,and Sr2+ have been determined during crystallization of Co(CH3COO)2·4H2C).Their dependencies on some properties of cocrystallizing salts(acetate hydrates)as well as cocrystallizing ions(M2+)have been analyzed.The D2/i values are comprised in the range of 0.004(rD_(Sr))-3.3(D_(Ni))but most of them are less than 0.06.This indicates that most of investigated M2+ ions may be effectively removed in preparation of high-purity cobalt(II)salts.M2+ ions for which |r_(Co2+)+ - r_(M2+)|/r_(Co2+)>0.05,cocrystallize with Co(CH3COO)2·4H2O only in slight degree(Z)2/i<0.06).Ions having electron configuration d~(1-9)cocrystallize with Co(CH3COO)2·4H2O on an average in the considerable greater degree than ions of electron configuration d0 or d10.