Effective and Ideal Separation Factors at Sublimation Refining of Sm, Eu, Tm, Yb

It is shown that the application of ideal separation factor in calculations of hightemperature sublimation refining of Sm, Eu, Tm and Yb has confined character: in considered base-impurity systems a difference between effective (β) and ideal (βi) separation factors increases with deviation of βi from unity and can be very significant; the measurable difference (in limited of a one order) between β and ideal βi is observed at deviation of βi from unity not more than 2 orders. The discrepancies between the effective and ideal separation factors in evaporative refining processes (distillation and sublimation at low impurity content) are not associated with the chemical interaction of the components.