Partitioning uranium/thorium decay

In the solvent extraction step thorium and uranium are co-extracted in the first cycle subsequent partitioning of thorium and uranium in the second cycle gives two decontaminating cycles to both products while using only five columns. For short-decayed thorium a reductant, sodium hydrogen sulfite, is continuously added to the feed streams of both cycles to decrease the effect of nitrite formed by irradiation. Without the sulfite addition, the nitrite formed by radiation decomposition of nitrates converts ruthenium to a solvent-extractable form. Acid deficiency in the second cycle feed is achieved by adding dibasic aluminum nitrate (diban). 

Another example of an important effect of bulk composition on partitioning behavior is provided by uranium and thorium partitioning into clinopyroxene. The decay series is frequently used as an indicator of the nature and timescales of magmatic processes (e.g., Condomines et aL, 1981 McKenzie, 1985). The parent isotope... 

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