PURIFICATION OF THORIUM FROM URANIUM-233 PROCESS RESIDUE

Abstract

ABSTRACT Thorium-229 can be used to produce 213Bi. Researchers in phase I human trials are investigating the use of antibodies labeled with 213Bi for selectively destroying leukemia cells. Other types of cancer may potentially be treated using similar approaches. Crude 229Th was liberated from Rachig rings by sonication in 7.5 M HNO3 followed by filtration. Contaminants, included significant levels of uranium, a number of other metals, and radiolytic by-products of di-(2-butyl) phosphoric acid extractant (which was used in the original separation of 233U from thorium). Thorium was selectively retained on Reillex HPQ anion-exchange resin from 7.5 M HNO3 at 65°C, where U(VI), Ac(III), Fe(III), Al(III); Ra(II), and Pb(II) were eluted. Thorium and uranium isotherms on Reillex HPQ are reported. The thorium was then easily eluted from the bed with 0.1 M HNO3. To overcome mass transfer limitations of the resin, the separation was conducted at 65°C. The resin stood up well to use over several campaigns. Other res...