EXTRACTION OF RARE-EARTH-METALS BY CARBAMOYLMETHYLPHOSPHORYL COMPOUNDS

The extraction of rare earth metals and nitric acid by diphenyl[dibutylcarbamoyl-methyl]phosphine oxide and O, O-dibutyl [diethylcarbamoylmethyl]phosphonate was studied. According to the data giving the dependence of distribution coefficients on the atomic number of a lanthanide, the pH of the aqueous phase, and the concentration of the salting-out agent-lithium nitrate, it was found that diphenyl[dibutylcarbamoylmethyl]phosphine oxide is close to trialkylphosphine oxides in its extractive properties, while O, O-dibutyl [diethylcarbamoylmethyl]phosphonate is similar to alkyl sulfoxides and trialkyl phosphates. Taking thulium nitrate as an example, it was shown that lanthanides are extracted with three nitrate ions into the organic phase. Using the equilibrium shift method, it was found that three molecules of the extractant enter into the composition of the extracted compound.