“…The processes of separation of stable isotopes on columns with packing differ from one isotope to another by: the elementary separation factor, the speed with which the isotopic exchange between the liquid and the gaseous phase takes place (kinetics of isotopic exchange), the size of fluid flows in countercurrent in the column, the chemical concentration of the liquid phase in chemical equilibrium with the gaseous one, the column temperature and the operating pressure. The proposed model can be successfully applied for other stable isotopes ( 15 N, 13 C, and 10 B) if the separation process parameters are known (flow rates and nature of fluids in the column, their concentration, operating pressure of the column, working temperature) leading to the determination of the constructive characteristics of the separation cascade (number of columns to achieve a desired separation, height, inside diameter, type of packing in the separation column (stainless steel wire Helipak, Berl ceramic saddles, glass balls, copper wire mesh, and connection mode of columns in series or parallel)).…”