METHOD OF ZIRCONIUM AND HAFNIUM TETRACHLORIDES SEPARATION BY MEANS OF RECTIFICATION Russian patent published in 2008 - IPC C01G25/04 C01G27/04 

FIELD: technological processes.

SUBSTANCE: invention is related to chemical technology of less-common and high-melting metals, namely, to methods of zirconium and hafnium separation from the mixture of their tetrachlorides by means of rectification. Method of separation includes supply of initial chlorides in rectification column under pressure, separation of zirconium and hafnium chlorides in rectification column; separate condensation and recovery of zirconium chloride purified from hafnium and head product in the form of hafnium chloride concentrate. Supply of initial mixture of zirconium and hafnium chlorides and recovery of purified fractions is carried out continuously with maintenance of constant melt level in evaporating cube. For maintenance of constant melt level in evaporating cube of rectification column negative feedback of control valve and cube level indicator is used. Supply of initial chlorides in rectification column is carried out under pressure of vapors, which is equal to or exceeds their pressure in evaporating cube, through the system of separate supplying melting volumes, which are connected to each other. Temperature and pressure in volumes of feeders from the first to the second are evenly increased.

EFFECT: provides simplification of hardware arrangement of process; significant reduction of metal intensity, increase of efficiency, stability and reliability of rectification plant operation, reduction of rectification column dimensions.

6 cl, 1 dwg, 1 ex