PRODUCTION OF RARE-EARTH-OXIDES OF HIGH-PURITY

A novel industrial technology for producing rare earth oxides of high purity (>99.99%) by temperature pressurized ion-exchange displacement chromatography is reported. It was concluded from the technological pa rameters that the concentration of complex agent in the eluent can be several times higher than that used in the classical ion-exchange meth od if a certain amount of buffer is present; the height equivalent to a theoretical plate (HETP) decreases linearly with increase in the ope rating temperature, increases slightly with increase in the flow-rate of the eluent and depends on the particle size of the ion exchanger. R are earth oxides of high purity were manufactured on an industrial sca le using a solution of special composition as eluent, and enriched rar e earth mixtures or single rare earth oxides with low grade as raw and processed material on a temperature pressurized ion-exchange multi-co lumn operating system containing polytetrafluoroethylene as the inner liner.