EXTRACTION OF URANYL-NITRATE FROM CONCENTRATED AQUEOUS SALT-SOLUTIONS BY TRIBUTYL-PHOSPHATE

Equations have been proposed for describing isotherms of extraction of uranyl nitrate from concentrated aqueous salt solutions by neat tri-n-butyl phosphate, with account taken of variations of activity coefficients of the components in organic phase over a wide range of its compositions. The constants of extraction equilibria, calculated for a standard hypothetical 1 M aqueous solution of uranyl nitrate and the state of pure components in organic phase with a mole fraction of 1, have been determined assuming formation of uranyl nitrate disolvate and trisolvate in the organic phase. The excessive thermodynamic functions of mixing tri-n-butyl phosphate with uranyl nitrate disolvate are presented.